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BS 4076 :1978';~1~lt~~
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Specification for
~.:
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;1
Steel chimneys
••••
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sua,.
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: ';",-,;~}~~}(.~~";~:
t
-
-----
r,,'."
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,
i
Spécification
des cheminées d'acier
Spezifikation
für Stahlblechschornsteine
I
f,
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CO\TE:-iTS
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f r o r;
Inside
Ccroeracing
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o
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organiz3tions
"ge
:2C~
Jver
S:ope
~e:~:::'~r',ces
3. De f i n t i cn s
4. Chirnney shells
í
Suppo r
i n g s t r uc
:;t.r~'~};;'f;:
Te r-pe ra t u re coefficient,
Carrosion
allowances
In,ulation
values
Va l u e s oE K for d i f Ee r en
4.
2
FIGURE
6
6. Chimney
:ini~gs
7. Exterior
insulation
8. P'ro t e c t i ve t r e a t t-e n t s
6
8
t
I.
2.
3.
1
I
I
ur e s
t
P age"iéPj"'fj:
TABUS
CO":_:r
SP;:CIFICATlON
S.
__.•••• , _,,_o
! 978
BS 4076:
,.
••,_~.:..-;_~
Kc
",~o
3
cypes.of
t
c c+ s ; :"'.!t.:tlon··
,,
I. Effcc:ive
height
of chimney
i
shell'
1
9
'j
APPE~,D ICES
À.
In sp e c c i o n anà
B.
C'.
~ind
ma i n t e nanc e
oscillacions
excited
Re corrsne nd a t i ons
an d' o t b e r
S
tee
for
t he
USe
11
11
of s
t
e i a l= s s
;;~~~
13
15
-v, )o{.
~~:i
.:::
i~6:~·
~
.:
.•••1':::
.' .:
"'
FORf.\';ORD
This
standard,
which has beeo prepat'ed t;ndet' the
d i r e c r cn ':)f"che
Coces
o f Pr ac c i c e Corr.n t t aa for
Ci"il
Er.?ineering,
'.Jas f i r s t ?:;t>lis~ed
i r: 19ÓÓ.
Si:~c~ rhat ~la(e three anend~e~~5
h~ve be0~ issue~
wM~_ch hav~ d~alc ~ith the eff2~t
~[ w~n~ ~~
í
í
cirClllar c11imney shafts
r e l a t i oris h j j, w i r h CP
Lo
ad
s
".
A
FAneral
r ev
in ord~r to ~ai~:ai~
Ch ap t e r 'i: ?art
i s i on
o
f t he
s r
and
3:
2
c
r-;
the
'\{ind
nas
heco~e necessary,
afcer the require~e~ts
~f this
st~ndard
hed been a9plied a~d additional
eXt'2rie~ce had heen gained in i:s a?pljr~~i0n
c u r i nc the i n t e r ...-e n i np y e a r s . Th~ ()pror;:!.!~!i.ty
nas
aL;0
b e e n t.!~e:1 to ::'Ptricate
tJith
BSr ?nlicy.
:.;.~t? s
t
a nd e r :
1:1
2ct:ordance
1[,:(> c l aus e dealing
t.~:<7q["lded
an d
t
he
r..:
w it h c o r r o s i o n h a s 02,,;:-1
';:CSiO~1 all,~)·.,;an::e 2~~:::.:-?ç l~
ence. In vip~ of che fnct chac
th~ light af exper
the majority
of ch D~ey shafts
are n0~ ~~!àed,
it
h0S
b~en cnnsidered
essential
tha: provision
be
~a(~e in this stan~ATd
to enSUT2 chat 5ecl~ ~elding
is carried
out i~ 2 satisfactory
r~~nner. As A
r~slJlt of c~is ~ev21o~me~t
it is no;~ 00r2 :h~11
-r
:l~:'C~~:;:;·lry::;'1.~': t"1J·:.'1U.-l~C
,~":~3~,:'.::r2:~.~·~ b~
given to ~ind effect upon s~ooch shafts cf this
constt'uction.
Appendix
B has therefot'e b~~n
t'evised and expandeà
to accord ~ith the I~test
te
i
ma t i
on t i vet'y important
con t ró've r s i a l s ub j e c t , A'lt ho ugh
mor e r e s e a r ch is
neede~t[n
this field, it is hoped that the
info~.r.;:,,:'1contained
i the
i wi 11 prove
Q! aSSi$(2~Ce
to designers.
clmic
a
l
n
fo
r
on
h
s
a
f'"
nd
. : ..
, ~.
o
n
app
e
nd
x
Ic has be~:'1 assumed in the drafting of this
standa~d
chae the àesign of ste21 chimney
s~afts
will b~ en:rusted
to appropriately
qualified
engine~~s
for whose guidance
ir has been prepared.
an d t ha t lhe
vo rk w l l be
e x ec o t e d und e r the
direct~a~
of appt'opriately
qualified
supet'visors.
> . ..
..•..
í
;
It can~~t he toa stt'ongly stressed
thar it is
essen[;~l
ar the enquiry st222 that alI t'e1evant
i n f o rrn.i
t i on b e p r ov i de d 50
t a a t the con:rac=ar
h as c o+ n lot e a n d s u f f i c ie n t in t o rma t ion . Any
special dcsign Ot' site considerations
(e.g.
fO'..lnda:io~s, which at'e not normally
designed
by
a spe c i al i s t chimney
co n t rac t o r ) should
be
inc ludrd 50 that a satbfacl0ry
e s t ima t e c an b e
given. T!1is will avoid any Qi$ll~derstanding3
a r i s in.; :rom inadequate
information.
~:cen:~J~
~3 also drawn ta
consen~ mAy be necessat'y in
examplc,
The Greeter
London
o f the Lo nd on Building
Ac t s
,
('0:
o
,.
'c:"
the fact that sca~~L:ory
cercein
cases, for
Council,
under Part IV
(Ameridmen t ) Act 1939.
100
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BRITlS;';
~ ~A.:;D/ ~
S'IEEL C .~~~EL
SEClrrC';'TIO~i
...;1:
•••
..
FOR
-------------------------------------------------------------------------------------------
'~f4~')Y
.'..ooft'
1. SCOPS
•
3_:
.~~~~,:":~',"
standar~
the structu~al
tO
d~sign
r
-,
and
of lini~i
o~ cla~di~g
e
a
r
to
í
ns
e
c
o.i
a
n
ma
n
e
to 1uch
nanc
e
a
r
e
ve
n
~idely iu height, 5hap~, pur?ose arrd de5ig~. The
design of chimneys of other than circular cross
section is not included in this standard. Chimneys
in pair3, rows ar gro~?s, a~d chose near oeher
struccures
of co~?a~~bl~
hei6he,
may be subject to
axcep~ional
~ind force and particularly
~inGinduced oscillation
greater chau tnat allo~2d for
in t h i s s t and ar d , Ap p rcp r i.at a exp er t a dv i ce should
ther~iore be obtained in chese cases.
The pur?ose for which che chi~,e7 is reauired will
àeternine whether lini~g, insulation
or cladding
is ne ce ssa r y ,
..'~.•.
il
e
..:.~ld. i c
r
s
z
ou.ic
a
ti
A ch icnay
on
s u p p o r t e d by
,
ch i rane y ,
i~
í
J~
c
3.10 b ra c.ic t , A co n s t ru c t j o n providing
r e s i s t ar.ce
to I a t e re ~ d i sp la cec.en t; o f t h e ch i criey , and zo r
suppotting
part or alt of the weight of (he
s t e e l c a i.an e y s , wít:h ar :..:~ti~out
a~à thei~ 5up?Orts, a~d to the
ch iran ey s , wh e r e r equ i re d , Re cotaaerid
a t i o n s ·...·i t h
g
d
p
ti
d
i t
gi
ap pe nd i x ..~
Th e p r i r c i p l e s d e s c r i b e d
n ~;d.~
s t arid a rd app ly g ene ra l ly to c h i.cm ey s v a ryi n];
"',0
_
relates
con s t ru c t i on of
li~i~5s,
applicacion
(
b
a
this
..~-::1o~nse~ c::i::cn7{.
~oi.le
';:"~':'~::';',
3.11 brac~~ted ch :::~~!.
A chimn~y ir. which ~ot
a11 e xt c r.:nI ap p l 2C 10aJ~ (",.g. ·.·ind) are
cBrriúd e:<clusiv~ y ~1 the structural
sh~ll a~~
for which bracke~s are provided
to ensure
stability.
The tities of the sta~dards publications
r2fe~red
to ic t~is sca~card
ar~ listed on the i~sici~ bac~
cover.
3.13 cleaning door. A door, nOl'2ally at che ba5~
o f the ch i.mney, tO p e rraí t the r enova L o f flue
dus t •
3.14 cope bando A 5(ee1 section attached to the top
the ch i mnsy ar o und its pe r i.met e r to g ve adde d
strength and corrosion resistance
at this level.
<\
For the purposes af (Oi5 British
fo l Lcv i ng de f in i t ion s app Ly :
~
.
í
3.15
cope no od , A hc cd fitted ex t e rn a Ll y to t he
t op of
Li na r , co ve ri rig t he up s ran d of the C2?
a
plate,
Standerc
~Ã;,
.
'
A
3.1 dccesS door.
perso,,~,"L.
~00r
for the en(ry
the
.
of
haoks. F::cings ~elded to a ChL~~~y to
pe rrní c toe a t t achr.er.t o f s t e ep lej ack s eq u ip.nen t
(see llS JÓ78).
top
3.3 aerodvna~ic
stabilizer.
~ device fitt~d
structural
shell to r2ci~ce ~ind-excited
o s c i Ll a t i o n s D/ ::1~d~ r:;i:-:; '':O:-~~·X s h ec d i n, .
,
~.
~.:
3.6
A horizontal
plate
fixed
:\ CO~i.':21.
c h i rrne y
COw
3.18 c rav a t
rooip~r
r a in wa t e r .
J.l
d
re.i.nf~-{L
r
)
to toe
bRS~
fins of ite2~
anci to 'che
3.7 base stool. A construction
vertical piates, welded to the
to the baseplate,
su~porting
a
through which the nolding-doN~
Eixed
ba~2?{ate.
comprising
t\olO
chimuej shell and
horizontal
plate
bolts passo
3.8 bl ank in z+o f f p·late. An irr,>e:
forate p la t c
fitted i~~ediateiy
beneath the inlet of a COtmney
to p r e ve n t t he was t e g a se s re ach í.ng t he 1.,)\""::'portion of the chimney.
.
j
-~~:1{~t~~-····,~:?:'\""t~--. . !!f4'II'
• .<.ifiii!'.i'!'
..,
:.1
l,
of:--zhl:
o
"
~~':'l~
wo:
\
«>0 '".
t,.'.~~,.'f!\'8:·..
.-
~~""'.......-;<r.~~~~""
t
0::- d isn e d C2.p
:i t ce d to th~
o r ed u ce Lhe in g re ss o f r a in
uo
]
,
up s t aad f i xe d to the roo I ,
cap plate to prevent the ingress
A:1
l:L; :,1(1:::!. .',
c
vhe r e i n c re as e d s tr e s s e s
pLa::~2
t'iX2J
o
t.Lê
s
n
of
a
Ll
:'J
o c cu r ,
3.20 double s!un c!\L~~ey. A chimney con s i s t i rrg o:
an outer load-bearing
steel shel1 and an inner
steel liner which carríes the flue gases.
3. 21 ~.
gussets. Tria~gular
tO Ch2 sneli ai' the chio~ey
e
to the
3.4 base cone. A trcnca:ed cone incorporRc~~
imme,:!Lately above t h e oas ep la ce of a ch i n.ie y to
reduc~ deflection.
3.5 baseplate.
base~~mney.
ai rain water.
te r.
t.J2
l
.'./ ..
th~ ingress
3.ló corrosion test o e ce . A f i xe d or r e mo vab la
steel plate insere, ~enerally of lesser thicknes5
than the shell of the chinney, in coutact with the
waste gas~5 end fittcd at strategic
poincs where
rna x imurn CU[ r o s i cn i s e xp e c t a d to o c eu r •
3. I 7
3.2 acceS5
.
to prevent
í
3. DEFI:-iITIO)lS
IC"
~
3.12 cap plate. A sloping plate fitted to the tO?
of the structural
shell, covering the a~ea
between ir and the liners and incorporating
c r ava t s t hr o ugh \.;hich
t he
l í.ae r s p ro t ru d e ,
of
2. R.E:Fé:~~CES
,
A w re rcp e attached
í
at cne end
to a
ch i tnnay :lr.J anch o r a d =t the o t h a r 50 as to p r ovi Le
t e n s i Le r e s i s t aa ce
[O ;::1.e La t e r a I d i sp Lace man r; vi
the coimn"y.
3.22 guy bando A s t e , l se c c i.on fitted a ro un d
outside of 3 chi;~ley with provision
for the
attachment
of GUYs.
t he
3.23 gu}:ec!chirrr~. A chirnney in wh i ch no t ali
externally
applied loads (e.g. wind) are carried
exclusively
by lhe stru~tural
shel1 and for which
guys are provided to eusure stabi1ity .
•••-~.....•.....- •.•.•~---.-
.••- ... -~~,,":,"","""'-'-'-"---'---.
~.---:_~--";>-...~.-:-.~
-7" .•.-:- .••
111,.1I1
•• ,."IIR'
_.-'ltll
•••••
"
.. 076:
55
;11~~1
1978
3.24 ~_~di::~-down bolts. Bolts built into ·t
b r i ck base
c r SU?PC:':'~~6
an ch o r ag e a t toe case
o:
CO:. _·e7."_cH'::1dacio~,
:- • .lC'k:..; •..·;:Ç
to p r o vi de
~r. i ::1'-,,/.
.J •
J.
.J02?iac?
15 e S •
~" 26
í
the
A s ho r t duc t f i xe d to t,;'le s ha ~1 ar
o f a ch i cr ey f o r t~e e n t ry o f f~t!·~
•••
~t
.I
inter::-.ediate
!:i~~·:,.;':T.e-i~a~2
::í1~
a~ded
3.27 joi~tin3 fla~~e.
A steel
section
fit:~d
ead ar a chi=ey
section
co ep.a':Jle sectiO:l3
cor.r.ecced
together.
Ducts
cantained
wi:hin
liner
base.
A suitable
a co nven e o t heíght
ab o ve
s t r uc t ur a L s t e e I shell
to
í
a structural
s cp po r t p os t i one d a t
t he b e s e p l a t e o f t h e
c a r ry t!':e Ioieight
of t h e
í
(B
through
tne
BH is
t ou r
p r ov i d i n g b o th t e ns
resist.ance to t::e later2.1
di s í) ~acemen t o f t:he ch i~
__
'""le)'•
.Ao
r i g i d "~l:1ber
í
(:c;:p;e3sive
ch
i rme
y,
t,,'J
Le
".. cs
of
in
this
3: Ch ap t e r V:
less
tri an 1.0.
exit
velocity_
on
referred
ia o~der
(s e e 7.1).
It
to mininize cold ai.r
i s s ooe t i ce s i n c o r r e c c l y
-
3.38 t~l~dish. A cc~ical ar slo?i~g
pla~_.~p"rovid2.d
v it h f a c i Li r ie s ~~r
bla~ki~~-off
d r a i n a ge .
.s ,
-~;;~~:l
:h:.~~<"J)C,-j. ..\ ~,o Jt~ c e s i ,;r:
:::) 5 ~l?;: :"-~.
in
~at(~r ciear ai the cravat ~i,d p~'cve~t its rntry
í~to the bui!ding.
The d~te~~inaticn
recommendations
of
Part
2, and subject
oe
0~ d2a~
l~~J,
~ind
i c ac c o r d ar.c c wi.ch
CP 3: Ch ap t e r v;
to the follo~ing
the
for
level
above
factot
B at
class
for
~~lf
the
ground·
class
C at
t~e
... #/ ...•'.. -.
above
ground
h e i gh t; o f ch i mne y
for
the
(Ln
rn)
values
i
n
•!.
o s c Ll a t i on , o n e
sh a Ll, b e adop t e d ,
r
e
Pare
J
pcovisos.
'J'
c~:::
e
s
n
o
:
ch
For i.n s t an c e , he l i c a l strakes
of t h r e e r a i l s h av n g a p r o j e c t o n of 0.1 to 0.12
t i.ne s the
oI Lhe ch i rariey , \,,rCt!.:-'.c) 2qual1.y
s p ac e d , r cund t.h e p e r i cie t e r o
Lhe shell
a t a I)~tch o f about
t i rm-s the d i ame c e r o f t he ch i m..e y for nc r l~SS
t h an
t he lL:pper
or.e+th
r d of
t, I
í
í
í
í
?
. ~.
í
r
sh
a
l
.t",
I
(e) D·o':l,·ction. The de f Le c c i o n at the
top of the
chimn~y
?roduced
by the desiin
wind
load,
calcu~a[~d
as acting
on the circular
cross
sectinn,
in the case
of designs
according
to
4.I(d)(I)
or 4.I(d)(2)
shall
not be greater
than'
h/200. lhis
requirel:1en~
doe3 not incl~de
the
-:,..;ind ;'C':"'':2 C~1 s t ab i l i z e r s , no r do e s i:: ap p l y to
chi~~~ys
dasigned
in-accordance
with
che fo~ulae'
i n B. J. 2, and B. 3.3.
5HELLS
ar~d o cn e r ~.)a'.!3 sa a l l
factor
cn t rr.ey s less
t.h an 10 rn h i gh
class
B column shall
be used.
a
~',i.'
4.1 l..
oading.
J".
h)
.-
(3) Chi~ney5
may be dBsig~ed
in accordance
with
R?pendix
B to provide
for increase
af
Lo a.i i n g for dynami c e ff e ct and , if ne ce s s a ry ,
for
tr:", f i t t i ng o f s t ab i I i z e r s , li
s t ab i lizers
;'J'
-::.;;33:Y,
d
ig
e ch iane y
be ir. .i cc or dance
'.;i tn 4. J (d) (I).
to as a ve~cllri,
CHI~EY
~~ .
(2) 5elf-supporting
chimneys
not ficted
with
aerodynacic
stabilizers
or tensioned
guys shall
be so c!esigned
that
stabi
Lizers
o r guys c an
be fi: ced quickly
and without
difficulty
La t cr , i f requi r e d , L.e.
a l l owan ce for v i od
forc~
0n the stabiLizers
ar the Ioads
on the
guy s s l.a I I be made as specified
in 4.I(d)(I).
The ma i n ax t a rna l s t ru c t u r e
i o g any f l an ge s ,
e x c l ud
che
~,
c crie . ,\ t r un ca t e d cone o r other
t:(";lce
fi~ts!~~--cç
t o p G! a chir:::"ej ;',,') ii!-:reas~
::-:e grl=i
*
'?na
(I)
Cn irnney s fitted
'.o'Íth aeroàynamic
s t ao i l i ze rs sh a l 1 be designed
for
a force
coefticient
af
1.2 ou the part
fitted
with
scabilizers*;
The 1atter
shall
be measurad
as the projected
area
of circular
cross
se c t i on enclosing
__t he s t ab i.Li z í.ng r Lb s , For
o th e r t yp e s of s t ab i Li.z i ng devices
see B.3.6.
ara providcd ta ensure stability.
3.~37
the
and
(80
70
(d) Oscil Let.Lon ; To a110w
of tb c iollo',.;ing.procedures
í
3 . .'36 s t ru c t u r a l shell.
is
For
the
s tdj'ed
ch maey . A ch i mney i o wh i ch no t e11
externally
applied
loads
(e.g.
wind)
are carried
e xc l us Lve Iy by the s t r uc t ur a I shell
and for wh i ch
3.35
l cu.i
C )
H
H
appcopri~te
leveI
h i 5 r h e actual
rooE.
J.J!. s t ay •
a~d
4.
-
H
approp,iate
C
í
í
add
i.e.
3.33
self-stepTJorting
chinney •. A ch i rrrie y i n T..Jhich
exte::nally
applied
loads
(e.&.
wind)
are carried
e xc l us i ve Ly by th e s t r uc t ur a L s ae Ll arid vh i ch ,
't o ge che r w t h t h a fovnd a t í.on , w i Ll r e rna i n stable
unde:: a11 design
condirians
wit~.:Jut
additional
s upp o r t ,
i.nver s
2
wh e r e
3.32 ,oo:plate.
A p l a t e vh ch f o Ll ow s th'e con
of Lhe roof round the chi~.ey w~ere i~ passes
t:\~
requir,,-'
are
í
í
3.31
mu Lt i.r f Lue ch i cme y , A g r oup o f t:'JO o r rao r e
ch i rrmays within
a s t r uc cur a I f r acevo rk or a g ro up
o f ('';0 or more liners
v i tb i n a s t r uc t ur a I sh e l L,
ar
the
~ordar.ce
Je
calculata~
~'·.iQ~
.(
e.
í
l.i.ne r s •
~tUy1
che
O~
p
~or
1.
(c) Ea c co «: 51' For chimneys
o ve r 80 m in he i gh t ,
the f2ctor
51 shall
be taken
irom
the class
C
co Lucn , ::0:: th os e ch irmeys De c-."een I O rn and
80 m t h e c l as s C facto r s h a l I b e increased
by
the dirference
between
class
B and class
C at
the app r o p r i at;e level,
rau l t i p l ie d by 80 mi nus
toe ch rnr.ay he gh t , and d i v i de d by 70,
to
sh=ll-.-----
3.30
:he force
(b ) Fact.?r
5,.
The f a c t o r 5, inCP
Pa r z :'.: '972 s h a l L be t ak e n as not
expansian.
liners.
C~
ac cc r c an c e with
standa:c.
to che
to be
].23 lateral suo~o~~s. Su?por~s pos:tionec 2~
a~propriate
lavels ~ithin the s:ructural
5t~11
locate the liners and to allv~ fo~ their
inde?endent
í
~ind
fo:ce
0n ladder5
constructed
in
wich ~s ~21: fixed
to a chi~ney
shall
de t e rra i n e d in a cco rdauce
wit:h ê;"le
reco::-::--.en:i-ólti:>p.s of CP 3: Ch aci e r 1,' ..
c o c e , A t r un c a t e d cone
,::-:~:::"~~:I 5~e:.!. dt :i:1
Le ve l C"J r e cu ce c-2::ec-::u~.
!,~I:::":-~~~r1:eC~!1
3.29
(a) Force coeffícíent.
The force
coefficien~
a c r c u l ar ch í.mney of s mco t h cons t r uct on ,
with
no external
ribs
or pIate
projecti:~s
exceeding
l/ISO of the diacecer,
otne=
tha~
horizoncal
ones,
shall
be ta~err
as O~6•
í
d i arne t e r
five
':. "
:
,:;:":~:\~,
~\~~t
,.;.- .. :<>-"
(f) Guyec, stayed, bracketed
or gr~~p5 ~f
chiwneys.
Oscilla:io~
af g~/ed.
scayed,
b ra ck e t ed , pairs o r g ro up s o i s t ack s i s o u t s i de
(
;'
that the weighe Df ~he flue linic~ shall be
included i~ the ~2aJ
laa~) b~t its stre~gt~
sha~;
be ~xclud~J fro~ th~ :;.~~la~ioGs for be~ding a~~
stiff~ess*
the scope of this .standard excep: to require
that guys, stays ar brackets
shall be aJe~uate
to elioinate
appreciable
increas~ oi s:reS5 due
to ::1ovecant.
,
4.3.2
tsi nir: ..:1 thic:",,,ss c E steel
4.3.2.:
Chimney shell. The rain iraum t h ckne s s o r
the ,..Jad-b"·,d:1g cn i xney sh e Ll , in single or
rr. ~ c i p le 5.'e II corist r uc t on s
s ha lI be the
calculR>'
thickness obtained
from stress and
í
4.2
}~ateria ls
~
í
e.
â
4.2.2.2
High tensile steel: structural
quality.
The !:laterial used for tne manufacture
of high
tensile steel bolts, nues and uashers,
roe which
pe rmí s s ib le stresses are g ve n in BS 449, shall
have a Q~ni!:lum tensi1e strength of 580 ~/~2 and
other me ch an i c a I p rcp e r t i e s app rop r i a t e t,)
grade SOB of BS 4360:
1972.
minimC!m thickness
of British Standard
(se e
4.2.1)
hollow sec:ions sealed at the ends, used
for external construction
exposed
to the wEath~~
or other co rro s v e influences
sh a ll be 4.0
and for cunstructic~3
~at so exposed) 3.0 ~~.
The
í
=,
í
4.3.2.',
Angle I Lariç ec , Th a m i n irnuni t h i c k ne s s o:
j o i n t rig .m g l a s to chi rrie y f la~gf:'5 sb a l I be
6.0 mm.
4.2.2.3
Friction
gr~p colts. Friction
grip bolts,
nuts aod washers shall co~ly
with the
requirements
of BS 4395: Part I, and~shall be used
in accordance
with the requirements
of BS 4604:
Part
am.
4.3.2.3
SJpportinq
sceel~ork.
Th~ minimurn
thickness
for h~c roiLed sections used for
external
construc:iJn
exposed
to the weather
Sh2l_
be 8.0 C~, and for co~structicr.5 not so exposed
an d a n c i Ll u rv s t e e lvcr k , 6.0
r.n (s e e IlS 449).
These pr0vi~io~s
~o r:~: apply to the webs of
Br i t i sh S~:lndarJ (se2 4.2.1)
r o llad steel
sections,
or te pac~i"6s.
4.2.2.1
ni l
steel. Ali raild s t e e L bolts an d nu t s
shall have a tensile s:rengeh oi noe 1ess chan
400 N!=2 and a mi n i nu,n e lcnga t io n o f 17 ;:, as
defined i n BS 4190: i9Si
and BS 4395: Pare J:
1969.
"
corrosion
í
6.0
~
and nuts
the
4.3.2.2
Chimney Lirie r ; Ihe mi n imura t h i ck ne s s o f
the steel lioer in a cloubie skin ar multi-flue
construct~u~
sh~ll be coe calculated
thickness
obcained
[r.J~
stress consideratio"s
plus the
corrosion atlowatlce, but s~all
be not
less
than
í
Bolts
co n s i d e r c t i o n s p l u s
,-1..~O:l
ance (s ee 1,.3.-".5),
b ut s h a II no t be less
than 6.0 ~", nor 1ess thao 1/500 of the outside
d ame t a r o f the ch cme y at toe saca he i ght ,
a Ll ow
í
4.2.2
I
í
4.2.1 Plates and sections. Seeel plétes used in
the construction
of chi.:::neyscoraí n g ',;ithi:lt he
s co p e o f t h i s Br t i sh Standard shall cornply '••ith
the r eq u i re me n t s for grade 43A o f BS 4360: 1972.
Alternatively,
suitable
stainless
or al10y steels
oay be used in speciai ~irc~ta~ces
(see
ap pe nd i x C) b ut t h e t hi ckne s ss s sha Il Ot::é rv s e
comply ~ith the require=eots
of this spec~fication.
Sup po r t i ag s t aa Lvo rk a ad an ci Ll a ry f i t t irg s sha ll
comp ly .,ith t.h e r equ i rene nt s of BS 4 or c,;; !,d48
for àimensions
and witn not 1ess than gr2~ê 43A
or S03 in BS 4360: i972 f o r q ua li.t y .
í
4.3.3
4.3.3.1
!.
stresses
Al10wable
A1Icwable
workiüg stresses
shall
to tak2 eccount of the most adverse
General.
be calculated
4.2.3
Gu",. ropes and fittings. Guy r o pe s s n a l I
comply with the require~ents
of BS 365. Fictings
for guy s sh a l I be g a lva n i zed and s ha lI co.cp l y ."ith
the requirements
of cne re1evant: British Standards
(e s g , as 462, as 463, BS 464, BS 825 and 35 5281).
Guy ropes with hecp cores shall not be ,us2n.
t ernp e r e t u r e
to
h
r••••
í
ch
o r p a r t rnay
h e :-::er::ner
t
reasonabJy
be expect~~
tO be ezpcSicl and shall
be ubtain~d by DulcipLying
the allowable
stress~~
sp e c i f i ed ia BS 449 o r tae c otnpre ss i vs s t re s se s
fron the eyu~ticn
i~ 4.3.3.3
by che appropriate
temperature
coefficienc.
Kt, froa taole 1. The
expected
temperac~~e
of the steel components
shall
4.2.4 Access fittings. Ac ce ss flttings.sh 1l1
not be allowed to exceed 480 eC• The values in
comply with the r eq u i reme n t s of BS 3'ifT"i~.·':'h
between
attach:::ent o f p e rtaane r.t l adde rs to s te",1 ~(, -:-.r:eys tabIe 1 may be adj~s:a~ proportionately
c
.e
is
no t
comply
r e cornrae nd e d b'..:c. i f r e q u i r e d , t he.
w i t h the r equ i rcne n t s of BS 4211.
S:.J
t
L1
he .12~-iro.,l
TABU:
J.
'j
t
ao •..
:l::.::.<
·:al·~;~.s.
U·!PEP~\TLP-!:: COGFFICIU;T,
Kt
4.3 p.-S,signand cons·t7L:ccion
4.3.1
sheil
-'.',
The use of
companents
be ~n ~!,:r,:vrc.!2:1ce r..Ji~.::: (':-.e
.relevaot
cIauses of BS 449
,
.-'
I
:.1,:
....-
c:
..'.
~:
General.
and ochar
"
steeL for the
chimn~ys shall
r e qu ir erne o t s o t
Temper=:.-r
"c
~(~~.'
-30*
to 315
370
4807
425
J
1.0
I
,_ 0.9
" S~e
(C.H) af ap~e~~ix
C.
t S~e
(C.9) af appen~ix
C.
I
0.7
0.5
.(a) mi n mura thickness;
í
defl",ction:
(c) a I Lov ab La compressive
stress in circular
shells due to direct force and bending ~omént;
4,3~J.2
E~·.fer;;ti'/9
i:e ].1t o: cc irxieu s iie l L, Fo r
tll~ purpo~es of ~.3 •. 3. the efie~tive teight
shall be taken from
:gure I.
(d) a1lowánce
4.3.3.3
(e) allowance
(f) stresses
~é}·
I
I
~
•
ror corrosion;
con
~:
.deu["
__
The r e comme nd a t i.ons in BS 449 regarding
t ue
f o Ll ow i ng ma t t e rs sh a ll , hove var , be s up e rse.Iad
by the requirements
o f this standard:
.
(b) allowabie
,
structurai
af steei
for terr:perature;
due
-'I~i'··
r
o
uc
ng
,
ccnp
r
e
s
the shell.
s
í
va
s
t
re
s
s
To
c
aus
e
d
by
f ib re s t re ss due t ,
bending and d i re c.t load shall no t ex ce e d the
following,
redu:ed furcher, if necessary,
for
temperature
(sei 4.3.3.1)
and ca1culated
with the
corrosion
a1lowap~e
jed~cted.
to wind.
Ali rnenbers, incIuding
guys,
.taken into ·account in design
Compressive
stress in
L b
k Li
th(>
the comb irrat i o n o f e x t reme
t
if any. shall be
ca Lcu Lat ion s , e xcap t
3
~~
.., ',.,:;S;.~..
~~~.•.. }'i-)i!.';,,~. s,1
··~·\l·;9
\,
..~r~;O:-"'·"'''''':'":''·'''·,:"~~~~~·~.,........r''
-:",''''-~,,,',"••"~'-"""'~.-''''~
.•••••...•••••.••.•.•...••
."... ••. - .••~_ .•>'-.,"
._- ...,.
••" •••
_-
..,••--.,. •...-...,..,..--~--,-_.,
.". -
._-:::;.;
1.11
.,.-<,
, :~~'~~~.~Jéi~~·
)·;r:'·BS,'4076:
. 1/.... .' ~
1978
;:"
\í~~roop,",,,
seress
v"
115
(.;/=2)
.~ ,( B
'
4.3.1..3 Internal carrosian. The corrosion
of the
internal surface o~ a chi~ne; is a direct resule
of th" corroslve effeet of the flue gases ""hi::h
i t c a r r i e s , If the flue g a s e s a r e of a
ncn+co r r o s i re n a t u r e , DO co r ro s Lo n a l Lowanc e is
h
"'"where
A
h
0.54
,--"'.;0'... :
"
-
'. '"
h
i .Lf ~
D
'
(0.019
+
,')1
'-
e
i: D
I
e
2 I;
»
rec u
F' re 'sa:;~3 a t t a c k ~·~.e i n t c r i rr su r f ac o s
d C:i:--:-:·.c:': ii '..:..;~J02:15ac~o!". :.:1kes t.-' ~·.Jl.e.
I':: th2
D
í
'~I
t
(
•
~_.
inner
.urface oE :he chi~ney, whi::h í5 in ccntac:
the f l ue gaSe-s,
is a Ll ow e d to f a l l b e l ov t h e
,cíd ce~ point ar the gases (:or normal boiler
~lue gases this m2! be taken ~s 132 °C)
condensaclan
cakes place and acid attack results.
[f the inner surfece oE the (hi~ney is kept above
~he acid de~ point cf the gas~s which it is
c a r ry i ag , i nt e r n..ai. a t t a ck
·il~ t ak e p l ac e anil'
whilst the inner se=ia~e of the chimney is being
heated to above th~ acid de~ point. This a~ot.:nt
af corrosion
shall be taken as 'average' in
table 2.
1"\
'.•1 :.:
2 70!:..
o
.,', and D
.'.
!2
~
..
if
(!
\
<
ó7
-
.!:..)
i ; "--"
J
U
J:)O ,
3':: ;
3 '"
t is the thic~~êSS of ?~2:c a c
considered
(ie. m)
where
r,:...
a: c.he
D is the cean dia~eer
consicered
(in c)
".:
.~:~
~-':.,:-.~'..
.~.,~""'.",-
leve L
th a
l••••
leve 1
: :~ \' .•.~·'w'
•
h
:;~~·r:.'·
-
is the eifective he~g~c for consideratio~
e of buckling
( ia m) (saa fig~re_I).
~.3.4.4 Temperature control. To ~Âíntain tne
te~era:ure
oE the lnner surrdce oE the chi~ney
'/-'.'-'
4.3.3.4
Deflect~or. stresses. If the c~l~ney carri25
.: a vertical
load other t
it
i t,
f
exa:nple, to the r e ac t on of S'-lys.
a he avy l i.n i n g
",';~:'
or an imposed Lo ad , s o that ao app re c i ab lê!
~~';.'~~co!llpressive
stress results, deflection
due to w nd
":\cay cause the a x i a I load to o e corae e c cen t r i.c ; t h e
,"Tcoment 50 p ro d u ce d shall be determined,
added to
''':"thatfrom the ·..,rindload and any o ch e r live ar d e a d
'"load and used to c a l cu l at e t h e co zb ne d s t re s s e s ,
"which sh a I I no t a x ca e d t h os e s p e c i f i.e d i ..•.
4.3.3.
This procedure
i s ne ces s arv only i f t~e total
/axial
load p ro duce s stresses g r e a t e r t.han I/J"'/H
":~:thebending
stresses due to "..Iind.
h
an
s
ovn
••.
e
gh
du
a
,
c
abo';e the acid d~w point
::1ini~izE:
r
ticting suitable
clause 7).
í
,'o"
heat
ChE;
lo s s ;
cladding
it
ij
t h is
ar
necessary
be
can
to
a c h i e ve
insulatian
d by
(se~
(
í
4.3.4.5
Allowar.ce Eo~ ca~r4:ion. The total
allo""an~e ior corrosion shali be the s~ of the
exter~al
(Ce) end internal (Ci) allowances given
1n table 2. 1hi5 cotal allowance
sha1l be added to
the thickness oE sheLl obcained Eram che
calcl11aéion of the stresses and defleccion.
Inter~al flanges shall have corrosion
allowar.ce
Cio and tne externaL flanges corrosion
allowance
ce on all exposed surfaces.
í
J'-,
"':.:'4,.3.3.5 Safety i ectio : of gt:y rapes and fittinqs.
A
minim~
factor of safety of 3 shall b~ used: i.e.
__'designed b r e ak n g load;;' 3 x raax imun calculated
',",' Lo ad , Be c aus e o f the large v a r i e t y o f f i t t i ng s
"'(see 4.2.3),
g r e a t c a r e s na l l b e t ak e n
n the
f t.h se i t ms , to
t
the ..
,,,minimuCl f ac t o r of safety is p rov i de d by a11 '.'.,
components
o f toe supp or t í.ng s y s t ems ,
~~--;
IA3LE
í
Degree
í
:
s
e
Le
í
ct
on
o
e
e
e
r
s
u
r
e
h
a
2.
CaRROS IO~
ALLOl-iA.'iCES
corrosicn
of
D('sign
expecced
Ext e rna • C
,e
'.-;..4.3.3.6
Stresses aue to wind forces.
Except for
--'~,stresses caused by f a c t o r s de s c r i b ed n 4.3.3.3
and
'those for ch cr e ys d e s i gne d in ac co r d a a c e w i t h
,4.1 (d) (3),
t he a I Lov ab Le s t r e s s e s g i van i n this
spsciiication
may be exceedeci by 25 % 1n cases
where an increasi:: in stress i3 solel)' du~ to wind
forces. nie s t s e l th ckne s s h ove ve r , s h a L no t b e
''less .th
that
if the w
stresses were
,.peglected.
í
j
í
ne
e
de
Ab o ve
í
\ooe
co
s
n
o
h
Ln
(i.e. unp r o t e c c e d
r age
me:
mm
1.5
Í
20
:-;il
13.0
f~
e
a
Ll
arid
e
x
e
a
Ci
(e.g. non-corrosive
;~ses
c r t:\e s t r u ctu r al
o f ~u 1.; i p 1e c h i :~ne J' 5 )
Generai" A cn i nne y s h e 1: is s uo j c c t to
by
r ro io
b t
t rr
y
t rri
y .
The corrosion
of the exterior
ser face is caused
,by at mcsphe r i c at t ack : t h s i s r.o rraa l I y min i ma l
, compared with c:-:~ at t ack whic:, t cke s p l a ce on .~he'
:,inner s ur f ace
ue to the co r r o s ive e f f e c t of ~-e
'or :
::'",i:;':1ey ~ó
:'Jr
prdtracted
per ods.
ack
ave
Internal
nd
'4.3.4.1
tt
y e ar s
í
d
:::··4~3.4 cor ros i on
a
10
)'ears
:;one (i.e. p a i n t , i nsu l a r i on ,
c l add i a g ar s i ra i La r p r o t e c t i o a ) l:-;i1
í
an
life
~
..\,-:·e:-ag~
Ll
(eg
ar na~u~al
.
I i n od ,
flue
she l l s
Nil
~il
I. :;
3.0
3.0
5.0
No t
~ot
i n s u l a r ..-·.j
gas-fir::.!)
í
,
flue
gas
e
s
:~e
ur.us
e
Ab o ve
;
.~.
oLl-fired
.~
recorr:- recor:l'"'
lCended rr.ended
:.• 3.5 .:;11o".N2nces to r Ler qe a.::ertt:res in Sh211.
~ha ailo~abl~
str~jj~S ap?ly co the shall ?la~as
after Jue alLowanc," ror rivets and bolt holes.
'.,'bereLa r ge ape r t u r e s are cut in the shell plates,
as for i n Ie t s o r i n sp e c t i on p ane l s , a s t ru c t ur a l
analvsls of the stresses shall be ~ade and
cOlCp~n$2ting ma t e r ia l p rov ide d , as r equ i red , to
~nsure that the str~sses specified
in the
5tandard are oot exceed~d. Ap2rtures
in the shel1
.
··..::·
.....(b) acne, i.f t n e e xt e r i o r i.; .r.a at a i ne d a t
re gu l a r í.nr e r va l s .and p r e ve n t e d from rus t ing ;
'<~'::"regular'painting ;lith a s c i t ab l e pa i n t is an
,':~_.
ef.fective t re a t raen t ;
í
:c?,::'
(c)
above ave rage , f it i s unp rot e c t e d by
painting
or ather exterior anti-corrosive
treatment.
~\)al-iired)
I
(e.g. l1n~rotected
(a) none, if t he chimney
fs fitted with
weatherpr~of
insulation
ar cladding;
.. :.~
-?.52
í
'4.3.1 •• 2 External corxoe i.on ; T~.e a-ncun t o f
•
'corrosion
tlh::'chx ak e s p La ce c n t ne exterior of a
chi~~ey shell (see table 2) s~all be take~ as:
"
E! r
.~:~ce? c o na i
~
C""
av
(e.g. unpr0tected
í
•..
4
~r
""';
.
.~~;!
\•..•. :~~;.'
"
..
',
(
..•.....
'
..
.~
.....
':
plates, cther than ·fiue inlecs, sha1i ha~e ~he
co rr e r s r ad ius e d to a ::!ir1i~;';::l c i tO t, ·.<;ere
..
t
is the thlCkness o: t~e plate.
4.5
4..3. 6 2as~?;late iL--:':! ."--:·:)2:::;:;-r.c~r:.co : cs , ~~.::
b
p l
d
l d i g+d o-....
it
h l l 0-.:>
qua r e
to
t ak e r h e Lo ad s t b e n d i n g ~o::-:~n~;s
;J.:10
r e a c r i on s
bet~een th~ shell a~d che· s~9Porting s:~~cture
or fOl:ndations, the position of ~~lding-J0~11 oolts
~~q~~re~2:\~5
a
s
e
a
c
e
an
and base
o
n
gussets
-n
co
or stcols
s
s
a
a
t
í
,
.,'
'
..
"
lt i s re cornmende d that ve Ld n g p roc e du ra
approvdL tests carried out in accorda:1ce wich
this sca~dard and witnessed
by an ind~pendent
inspecting
aucho:lty
should b2 accepted by ot~er
i n s p e c t i ng aut ho r i t i e s p r o v i d e d t h at a11 t he
provi~ian5
have bcen fulfilled.
..
,:,.,
í
.'i
~...:
mae
arid
to
l
r
r.e
an
s
e
h
e
í
a
4.3.10
Sealing.
Ri ve t ed ch raaeys should b e
caulked, especially
if condensation
is likely
occur.
The welder who completes
satisfactorily
tha
procedure
ap p ro va l test is thereby exetnp t f rcm
further we lde r approval teses involving
the s ane
range of pracedures.
í
to
4.3.11
Gas tight.'1ess.
Lh e degree of g as c ight ne ss
shall b e app rop ri a t e to t he ch icn ey s USé'.
4.S.4
of weI ds (shop eriâ site).
In
h e r cq c i remo n t s of 1•• 5.1,
the
manufactur~r
shall Ddlntain
quaIiey control by
4. J. ::1 s roce cx ior: eç e.i rvs t: l i qn triiriq , Su i t a b l e
periodicaL
checks. These shall consist of
protection
against ligh:ning,
in accordance
with
radiographic
examinacions
carried oue in
the reco~~endacions
of cha relevant claus2s of
accordanca
wich
the
requirements
of BS 2600:
CP 326, shall be provided.
Part I, and shall cover an aggregate
of at leasc
4.3.13
Erection
tol~ra~ce.
The departure
af the
3 m af concinuous
welding to include at least
ch i mn c y f ro:a the ve r t i ca I on e re c t o n s r.v. 1 .io t
f o u r s e p a rn t e j o i n t ..• a c e a c h t h i ckn e s s p r od uc e d .
excee.J 2S
or 1/1(1,'):lf
t hc he i gh t , ·..;hi-h·_:'.:e:
is
1 li ~ p" r i ('.
i i c c h e c r~s :;r. a L1 t H k e p 1 a c e a t i n t e rv 2 1 s
che g:eacert
at any ?O~~t.
ai ~ot ::l;~2 th~~ th:'·!e m()n:h~.
e
=
Fixing
4.4
.',
~:~'.
:,:"
,.
.
~ ',O
..
'
.:
(:
.'
.(
<:0
t
í
of ~uys
lhe
accepta:1ce lcvel6 shall
1 i n BS 4870:
Pare 1:
be in acco~~ance
wi~j
4.4.1
t ab l e
There s h al I be a mi n imu:a of t h ree guy r ope s to
each set; guys shall be positianed
radially
i11.
plan and the angle bet~aeg any adjacene pair cf
guy s s h a l I no t exceed
130 •
••
\-.'henrando", radiagraphy
af part of a weld reveals
unacceptable
planar defects,
two further welds i:1
the group representcJ
by this weld shell be 30
t~s(~d t~ :':2 S3~1~ ~x~~~t. !~ch~s~ ~u~~~er ~~l~:J
show no u~~~cept2ble
planar defects,
th~ defects
in t he I i rs t we ld s sh a Ll be r ep a red and t h en
re-radiogiaphed.
lf the repair is satistactory,
the group af welds shall be accepted.
Position.
Guys shall be positioned
su f f i c i e n t Ly b e Lov t he outlet o f the ch i c.ie y to
avoid the corrosive
accion of ehe emergenc
comb u s t ion produccs.
A rai n imun d i s t aric e o f 'J rn
i s ra:::'J::=.e:,.C-2d.
The guy rapes shall
the horizontal.
...
Ouallty
add i t icn
t
"
í
4.5.3 vle':'c1er e pp ro veL tests.
Welders ercp Ioye d i~
the manufacture
2nd erection of steel chi~eys
made in accordance
with the requirements
af this
standard s~all have been tested by the
manufacturer
"Slng an approved
procecure.
Compl~te
racorda aE such tests shall be availab1~
for
ns pe c r i ou by t he pu rch ase r ar h i s r ep re sen cat i va
as specified
in BS 4871: Part 1.
4.3.9
Clear~'1ce. wn;,re a ch i cm e y pa5Iê·~',[hrough
a rooi ar other pare of a building,
provision
shall be made to acco~ccate
che I:love~enc o: tne
y
i rai
t
tr
f r ai
t ,
Norcally
an air gap of 50 rnm ls desirable,
but
flexible heat-resista:1t
packing may be u~ed.
ch
511:.
~;OTE.
=.
í
.~j
A ~anuE3cturer
shall be exempc fre::Jmaking
procedur~ tests ia accordance with th~
reGuire~~~ts
vi chis clause when he ca~ show tnac,
for the !Jrc·,ious t~lr~e years, h~ has 5u~cessfuily
und e r t ak en t he \':le l d i ng o r s t e e l ch irnne y s to a
qUdlity ~quivalenc
to that required by as 4870:
Pat:t : i:l the p ro ce d ur e s f rorn wn i ch he s eek s
e x e mp t i o n ,
o ase gu sse t s
e ra o ly o e .
e 11. Sr.oLl e r
t we ea r he na i a
4.3.8
F'la.'1ge bolts
i."l the str:.JctlJr~s!:e~1.
AlI
flange bolts ia the s cruc t u ra l s he lL'<sh a ll o e
pc s zi orie d not more r n an f ve d i ame t e rs c,e[\·Jaen
cen t r e s , wich a raa x i oun o f 150
Ac co un t shall
be takan in the design oi the bolts for the
eccentricicy
due to che bolt position~~
í
"
t
Base g u s se t s s h a lI De of acp le height a:1J s na ll
extend :0 :he edge c~ the baseplate.
The an31e
of tne slo?ing edge of ~~y gusset to the
horizoncal
sh a l I be n o t l e s s t h an 60°.
Tu e .ni.n i raum
th i ckrie s s ai che 'gu s se t s h a lI be 6.0 ='.
~
o:
t s for
we l d i riq •. t.Jeldi!"'l~
accordance
with t he
4.5.2 Pro ..,aurc D?proval tests.
Before a
ca~ufn~:u~~r
i~ pernitted to weld chic~eys in
aC~'.rJ~n~~ ~ith the requirements
of this Briti5~
5_Jndar~.
na shall adequately
a~d successfully
cest hi~ ~everal pro~edures,
and com~lete ~eco~J$
oF
." c~scs shall be avai1ab1e
for the purchas2r
~C
his r~presencative
as specified
in as 4870:
P a r t J.
e
being
4.3.7
Base çiis se zs erici stools.
r"ner
ar s t oo ls are used, t~ey sh ou ld pre
e ven l y d i s p o s e d ro und t h e ch imney s
s e co nd a r y g us se t s ca;: be p ro v i d ed be
gussets.
. j
c
Ce:ieral
teq ui remen
b e c a r r i e d 01lc~.;
~ ~5.1
:aken i~:o
be a de qu a t e ly
t i cn s :0 p re ve.r
the st,ipping
cf tr.reads, and the :,aseplace shail
be p:operly
giouted .
í
~/: .
. ", ..
n
ielc~:lg
!•.
shal1
acc o cn c , Ho Ld i ng+dc vn oc lt s shall
t i.gh
t e ne d , •.•• t h
ap p rc p r a t e p r e c au
,.:,..
1973
BS 4076:
not exceed
an angle
•
ai 60°
í
lf one af the cwo Eurther welds shows unacceptable
planar defects, each weld 'in the graup soall be
radiograph2d.
Unaccc?table
defects shal.l be
r e p a i r e d ..lurJ th e n r e+r ad i og r aph e d •
to
4.4.2
'::.recr:io."l tzeris i or: , Th e tension
n C"" t,'.:ys
after erection shall be not less than 15 % nór
more (han 30 7. of tha calculated
maximu~
tension
,due to the wind.
í
4.5.5
í
.... ,
Si tc, wei iriq
â
An adequate and prap~rly-supported
worki~g
platform
shall be pravided
to enable the walder ta
stand and move comfortably
in the positiún he
normally
adopes at graund level to carry out the
welding.
4.5.5.1
4.4.3
si te .tensioning
of guy roi.es ; Th e anoun t of
p re+t ens io n ng ap p l i e d to the guy ropes on s i t e
shall be in accordance
with tha appropriace
desiin
considerations;
it may be measured by the use of
a suieable
instrucent.
;
1974.
5
,
J.l}'t>;
!;t~
t'3/
:,)
,~
\~~~:!:
':"';il"~~
~~;?: .
ti~es
~oe ~aximUQ overturning
moruent due tO
stres3-increaslng
dead loads,
leiS 0.9 times
due to stress-:educing
10aJs, plus 1.4 times
due to ~ind and imposed Ioads.
-;:"',-:4.5.5.2
The weLdi ng area an d ·..;orking p La t Fo rm
'~'~~:;.'~:
s ha L~ b e pro t e c ce d ade quat e ly f roei t he ve a t he r.
',){,~'.~~
_->'-./ •• 5.';.3
Su r f a ce s to be •.•e Lc e d shall
b e free f r orn
<;"'-~~i:;t:ure.
Pr e c au t ion s shall
b e t ak e n t o prevent
. ~-~~.,,:.
...
'<~4i;}::::,t~~:1'de'scent o f CO~ s t ur-e (1. e. :-a i n anó . ".::.
..tff,·~~i~L~·nâensat.i.o:';.)c n to toe t,.;e:::::~:;6 are a ::om t h e
}~tt'structurc
ab ove the po int; o i. ·rielding •
• ,-~;.;.'l.:>~;.
.. ;
-
<0.9
:\.f2
'.,.i:
Ma
';'/.";
)í.s - toe ove r t u rn ng morne n t p rc Ju ce d b;: crie
winc and ioposed
loads (i~_;~)
f-!..;
í
í
is
.'{m
í
".fe
;~{:{~':'>~~~~RTL"G
t
rie ove r t u r n ng
í
l o a d s wh ch ,na!
combi~ed
moment (i~ ~
exceeding
•..•
1·•.•...•
~·~I
(
í
,)
c c r e as a
~:
"
"
-r
thc
fcundatioil
bearing
,I
·t,
pressure
n :, m)
í
t ~:'
í
í
:<i~,~~P.,~2004~
.:_
~;;'l~iÀ"ehiinnéy taay be counted on t h e smoke box of a
j~,';~boiler,
p r ov i ded t ha t the s cok e box , boi ler an d
:.-B,::boiler foundation
are de s gc e d o r strengthened
,::;;:~f .to' comp Ly with the re qui r eraen t s of BS 4t,9 and
í
•.
í
ln the case of se1f-supporting
chi~~eys.
the
require~ents
of 5.2 shall be observed
so that the
speciiied
combination
of loads will not produce
roore t han 1.8 t írnes t he al:":,·"able foundation
bearing
pressure.
Subclause
2.3.2.3.3 of
CP 2004:
1972 may b e app lied whe n ca l cu l a t ng t he
allowable
bearing
pressure
for liruiting
settlemen~,
but no reduction
in wind load o~
increased
bearing
pressure
ir: accordance
with chis
sub c l aus a shall
b e ma de when designing
for
foundacion
Ioad limicacion
to prevent
shear
failure.
í
-:t~
':
r he r e s t o ri n g morae n t p ro duce c o y t h e
f o und ac ion v i chout e xce e d ing toe allowable
ma t er i ...
r l s t r e s s ano the g r oun d s t r e s s w i th out;
STRt:GURES
<":-'
ro duc.id by cead
ae:"
í
:'5
H;)
":?' '5.'1 'General.
Structures
sup po r t iag chioneys
shall
'l"'be,,construc::eci
o f s cee l , co nc r e t e , b r ck or o t he r
)~<;,suitable
mat e r i a l s in accordance
wito the
requirement
s of the re levan:: Br i t sh Standards
or
'~~-codes
of practice
for the c!asign and use of thes<,
~;-""'-',ma:terials. Reference
shoul d De ziad e to the
reco=endations
in the f o Ll cv ng do cumen t s r
);:)'-BS 449, CP 110: Part I, CP 111, CP 114 and
p
.t
[;lOS';'
o r othe r
i s t h« o ve r t u r a i ng .rro men t produced by de ad
or,other
10êds which act àt alI cimes to reduce
combinéd ruomenc (ir. ~ m)
:;j~~(';~ :'.",':".." . \,'
!tii;~:;5.2,Stability.
_-:iQ';. wh~re w~nd
1r:~;~',:load carried,
0.9
.'·Im -
(
where
ALI ~lectrio
weldir:~ cr: site
shall
be
out •...
.i ch t he ::Jlni::JG:l p r ac t i c a I length of
cab l o be twe e n the -po·..-er source and t he
ar e a , The supply o f -.'eld:ng current
in
of vo l t age and aep e r a ge shall
De adequate
welding procec!ure b e i ng erap Loye d ,
.:~~~1f,~
:,2004.
1.1
+
i
p a r t s be i ng cor.ne c t e d by wl:Iding s h a I 1
f i rml y to e ach o t ne r by bc Lt ng ,
o t h e r me chan ca 1 rae an s until
welding
i n the a re a ,
'rr:":-4.5.S.4 Al1
',~- b-e attached
"c Lanp í.ng or
.v-. i8 compl-ete
4.5;5.5
carried
_li:'; welding
.:;(, working
'-}',,irespect
':;'$;,'_ ..; for the
i e , 1.~:iN
Chat
that
.í
,e , 1.6
0.9
(a,,, + C'm) -
0e
1.8 cf
<
par: of the structure
are reduced by the dead
and ",-hera this i s t ake n into
_~~~:
-accourrt, a c a I cul ar on shall
be cada t.o shov t h a t
-'fl}~: the--stress
- ic?osed
by 1.6 t ice s the total
of wind
::-::~~~load.p Lus any s t r e s s+Ln c re a s i rig mpos e d loads,
:_~jÇ'i_-less0.9 times the .mín ímum d e ad load e xc l ud ng
:;'}~;:::anys t re as-e r e duc í.ng Lmpos e d l oa ds , w l l no t
exceed 1.8 t i.zces the. a l l.owab Le s t re s s s pe c if i ed
where
<~:-;'
6. CHI~~EY LININGS
~
'.-.~.t.~.\~~{_
~::.3;:~.•
6.1 General.
Li n i ng s for steel
ch íraney s may ':te
required
,for one o r more o f the following
purposes :1
j
For every
Lo ad stresses
~i
0w-' c~ and 0e are
defined
a~ i5 the allo~able
~ (Ln N/m2)
í
in 5.2
foundation
bearing
pressure
í
í
í
-Ó,
•. -. .:
-:!~~)i~e~;'.1.6:(aw
+
0rn)
-
0.9
rJe
<
1.8
0a
J~
.i··
,.,
~~~~~~~~~'~~~~tt:_:;'~,
•'
':~~;i;~ciw'iSthe
s t r e s s produced
::j';;ii;;;~;~c?("c
'(in N/m 2)
• <
I
(a)
by the
wind Load
':tJ:~:~~;";·.'ÕJo''':~~,;
,;'~~:+"àrtt"is .ché s c r e s s produced- b y any ocher load
.~~~~;<y,.-.may act to increase the comb ne d s t re s s
wh ich
(o) eo maintain
gases.
2
;:',.-kóa
~ ~ 1 _ ~._'..
_,_~st he ",,-_Q~a:Jl,-
.,"/' ";jA';Y' -,(i n
N/ m
'S.3
.!
covering,
.1
,
sere",
_..
=.
2 )
~...
• - • ~ ~
i
; ~
.I,
ci r e ..• __', ~.3.J
a
,
Foundations.
accordance
crri
~
~
thus
'~
temperature
of
che fl~e
~.
~
~
~~
a
a
nd
a
r
e
The foundation
shall
De designed
the r e cocrae nd a dons
of CP 2004.
.': ..•
~equir~~~~t
í
(c).
~~~ s~rengt~
an~ hard
--~~~~&Z:,~:~~."
. ~~-~ .. -.-'....·..t:f.~·'!:....
~-.;
~
frot:l abrasion
Suitable
propercies:
bricks
hav~ the
f0110wing
Therrnal; coriduc t iv i t y
about
Bulk density
not less
kg/m3
j
I
~
~
surface
wculd give protection
to the steel
when this has to be considered.
,
~
~
1.25 W/(m K)
í
' ._
,~
This type of linin~
fuIfils
rcquirement
(b) and
to a degree requirement
(a) in 6.1 up to a
temperature
of about 1200 °e, but its high
density
makes ic oE Iittle
use in respect
of
I.< i t h
,;;;;~.~;~tt~:
'-i::::'
~
~
~
1
~
the
n
~
f
heat;
Firebricks.
to suic
case o: guye d or La t e r a Ll y su opo r t ed
::~':chdmneys , t he s t ab i Li t y of 't h e s t ruc t ur e and
~. foundationas
a whole or any parc of it shall
be
Lnve s t gat ed , and weight or anchorage
shall be
provided
50 t h a t , ••••
ithout
ex ce e ding the al Iowab l a
,:i5tmaterial
stresses
and founda t on be ar í.ug vp re s su r e ,
.:X,'t,O.9 .t íraa s the leas t res toring mooent including
-~;::}J.ancho.ragewill'not
be less than the sum of 1.1
'<
fro~
These are made in radial
form
chimney dimen~ions;
firebricks
having
2.7"'1
l
CO:~:-?:".:
:'~t~·;2~i1 ~:'; ~
J:! :;
satis~dctory
for ~tte rr.ajorit)'
of applicacio:-\.>.
These b r ick s are SE: t in .nor t a r ffi2.Je f r cra g r c und
iireclay
ar io a suicable
fir~ cenent.
6.2.1
;.::'~,
úi, the-
-<
the
shell
6.2 }!ater'ials
,:i;/~:"~rtsure
s t ab i Li ty at alI t írces , ac ccun t sha Ll b"
-~ -taken of probable
variations
in dead load during
construotion,
repair
or other si:niIar
\..'ork.
"~>in
chimney
)
"?Ji~1à;':,;~is the s t ress produced by the dead Load
·:·"~:"-::;~':ii:"-.:and
any o t he r load vh i cn a c t s at ali times
It~T~/df,;;:'and will
reduce the corro ine d s t r e s s (in ~/m2)
\.:~~::;.ri}t;~'f~•.
the
'(b) to act as a protective
r e d uc i.ng co r ro s ion ;
í
-::f.~[(;;:~i,,"(i~ ',N/ro
to protect
than
2000
~
~
:~
<$
:~
~~
6
,':=>"
-;;;
.
".;,;-'."
.".
.
.~~
'~""""~--,~"~'---:-""'---"~.'-".
'--
..-...• - •..•~!·~·-r":"-:~-~~
."::;
...,~~':"""';·~::~~·······~·
••
,*!
j
.~
.~~::\~qJ.:
.
BS 4076:
.)
'1'
\!~
T'
·"·-e····'
··
·
'::-
-
• ~l>1
;;
-
:~
.. ~,.'
_:
'"
.
not
Cold crushing stren6th
~...
.
Coe~rlc1ent
o f ex~ans1on:
For
Le s s
ha n
t
the
I!. N/r::m'
t ernp
to 3 .3 x 10 -6/ K
up
o f g as , rC("JÍ~e::lent (b)
e r a tu r e r arige ) SO C to 870
t
y pe
6.2.5 Retractor!:, concrete.
A
lining may be formed in situ
'gunning' procesl. In use it
f ír e o r i ck Li ni n g 3.r.d fu l f i l s
(see BS !. 207) •
chi~,eys
taking gases from certain proces5 or
equi~:::lentac te8?erar:ures i:-.. ::.:eS5
o: -1~CO !)C, ,a b :'.:.;: ',..;i.-ch a ~igher ·;-:.~·~c::i:!2_~:-:'C':::lt
is nc~ded and 1 ni~6i ~or suc~ .~eeial _~cies nee~
'.individual
deta led cons d o ·_.:íon.
í.nc i r.e r a t o r
"1:
1978
.;.
° ir'.6.1
in
t
he
C.
r e f r ac t o r y co ncr e c e
or applie~ by the
is 3i~ila~ to a
similar
rL1I.l:'re-::..e~:s
í
6.2.6 Scl....íd d.t1d cetner.t mixtures'.
I'he s e ar e 5\.!~ta~:e
6.2.2 Solià grade c'::a:' .lceou:;
ar i ck s , Th e s e c an
for Li ni
t
t d by t h
'.: be mace to suit the
.a:r.ece::of che ch mney and in
more gen~rally for use in toe 10~ teruper~ture
ch ck ne s s e s (g e ne r a Ll y be cve en 7.6
and
I) 4 mm) to
range (see BS 4207).
suit the degree af ir~.: _:ion required. This type
6.2.7 O~~er materials. Uther lining ~teria15
~ay
of brick is se: :.. .co r t a r cade irom the b r i ck
be r e q u i r e d for use i n spe c a l c i r cums t anca s a..c d
material g roun d to pC'_'cierf o ra ví ch add t i o n oi
these shGll be applied inaceordance
wich the
Portla~d .cr high alu=ina cene~t) ..according
to the
manufactur~r's
specification.
gas tej~erature.
or in mortar suppli~d by tne
bric~ =anuiacturers.
Conditicns
like1y to lead to
6.3 DesigrL 2nd construction
10s5 of s t r e ngt h o f a i gh a Lura i a a ce.:::.ent
.1::2 kncvn
and
·,.;iere t
6.3.1 Ceneral. The interior surfac
of t~e steel
s í.gn i f i c an t ,
shell shal1 be e1ea~ and sha11 be reee from 100se
rust and scale, e.g. by wire brush ng, iomedia~ely
,~
This class of l n n ',;o\!!dcevar requite:~er.:s (a)
before applying the 1ining..
(
and (c) and , cep~r:c rg upo n tr.é type-'i:pf'ilas,
6.3.2 Tnermal expa.nsion. The thermal expansion af
.';
.. require:len5 (b ) in õ I ;;"ichin t
t
,f'
the 1ining sha1l be provided for in design.
range 150
C to 8üO c.
Refractory
and acid-resistant
linings shall be
When dry this materia: has a 101.1coeffic~ene
of
divided i t sect~H!s: a suitable
i
f
ti
expansion
and is reslstant
to te~eracure
changes.
lS 6 m. Each section of the linir'.g shall be
Beir:g highly ;;ater-absoroent
these brlcks should
supporteJ by an internal steel ri~g securely
be s t o r e d i n dry su r r o cnd i.n g s ; briek Lí n i ng s
attached to the chic~ey shell. A space for
.shou1d be drie~-out
slo~ly and, preferably,
_
expansion
shall be 1eft above the top of each
maincained
at an elevated tenperature
tnereafter.
section 50 that lt remain5 elear of the ring abo~e.
Suitable bricks have the following properties:
The expansion spa~e shall be filled with asbestosS
fibre, mineral wool or other pliable,
;
'"·Them.al condu ct i.vi t y
not greater than
nori+cotnb u s c i b l e f i l l ng ,
:;
ng
s
con
s
ru
c
e
e
! gunn
í
r.g
'
p
rcce
s
s
,
í
=
í
í
í
·.:-~:.~-~
sb
a
l
L
b
e
í de
avo
í
d
vou
í
l
d
b
e
í
~.,
ae
.
-'.,
:.
"
e
cpe
r
at
u
re
o
..,--
II~,
H/(m K)
0.23
Bu1k
density
Cold
crushing
o
he
gh
c
o
s
e
c
c
n
í
<~1'
not'less
kg/m3
than 700
no c ~ess
th~i· 4.6
The thernal expansion of solid grade diato~aceous
i
earth brieks. or of concrete made from similári
material, being Lov , sec t on heights taay be gr e a t e r, c.
and, for small chimneys, a 1ining Df thesa
1
mat e r a l s may be t ak e n a l mo s t to the top o f t he
"
shell without dividing ir irito sections. D\!é
co"sideration
shoulé be given to the reneat
shrinkage of these caterials.
í
streng~h
"/r=
_-o
/,)
1='
• t:)
p :: :.:::
CO_." .•.c i en
e xp an s i on
.:i;.;,
. _•. A'i.:::;,:...
".~~~1>~.~){>~
.~/:<,'<;l.',:~:~.~'
·8 r··
Moddus
t o r
~...
'
~
Li r.e
í
-6
ar
: 2. O ±. O. J
/K
10
x
2
o f r up t ur e
: 0.90
Nh=n
Toe upper porticn of such a 1ining is subject to
d~age
by weather and it shou1d therefore
.terminate at a d i s t anc e b eLow the t op
approximatcly
eqc.:al to the diameter qf the shel1,
the lini~g bei~6 co~?leted with an engineering
bric~ or d~nse fire~rick, jointed wich 2 suitabl~
rnor t a r , lt i s r ecorc.c ad c c t h a t t he t o p s u r f a ce o:
the lini~i should be suitably protected
irom th~
6.2.3 s.ci
xes i s tinç
c r i ck s ; The se are used '..l~en
.' .; ;·::{C>.
the ilue gases are h gh Ly ac d i c o r are a t
t erap e r a cu r e s a t o r be~o'.-I150°C
(í ;e •
n t l.c
,'Y~:'"
ne i.ghbou rhood of t r.e c.:e·,;
po nr ) , Th ey a r. se t i n
'.', ·I.~:...
an
i
i ti
Cê~d'.t
as the obj,'::l i
'.i•.... ,,:" ,.' .
to p
t
i:::;:e·'r·:ivc.:s
Li
g,
.:yj,::::".:'f.:~- . fluctuations of t
r
should be
id d ,
':,l~~r.t;~~~;'/":~$··,~r':~;
~i,other' ... i s e z he r í.g i o i t y of the
l n ng may C[:!JSê i t
â
í
í
í
í
ac
d+r
r
e
se
e
s
s
a
ng
an
an
er.c
e
a
tur
d
,
n
í
s
n
s
ar.d
bec:;::e
ve
r
e
e
a
í
·.::f~}f~·~~~{~:~:n.r,:~:·
to f r a c z u r e
e
Le s s
eff
í
vo
e
c enc,
í
L;
'Wll~''''-lí!",···,·
. bIe f o r
:.~L
...;/'Y~;;. ::.: t h at. t.h'i s c 1as s ~ f" :JrlC~,. 15 SUlCa
/;:!y7t;>~}i"'c':"I" r equ i r e ne n t (b ) i.n 6.1 i n c i r cums t arice s o f
;,~?:;?:::;:;.~:.,.: '; flue g as t erape r a t ur e ,
;.-!~~~.
-r~.,.J..~~:'~.
"';. '.
;::i.:~
...i:;,r;\.;.:: ~,>'It i s
.'
we a t he r ,
í
. .
..
~. .
f.'JlloYw·s
i o•.•.
.
p rac t c ab le to u se h í.g h Ly v i t r i r i eu c i ay
o r vitrified
f i reb r ck s r e si s t an t, to
í
:~:k<;::'~\í~~~j':~.;\;:
br i ck s
::1~~;~~~~';)"~"
~::~:~~~~;~;.up
í
te
°c
S~()
and
! 100°C
}-\,;#it'tYJ:<:' The acid-resisting bricks and cemerir vshou i d be
··;';Jti;"'~~:~tti,;;c:"'chosen
specifically
to resist toe acJG.s known o r
:.-:.~
..(,."",,";'';
..•.
:\:'0:.;;:';':;", ..:expectedto
be present in the flue gfses.
.
.
': .~'<-}i·~~~~\t·
,
'.-i'f:.• >'t.;;:.;':
: ,ir,,::,:;;!' .':;":.'.
<,.:.:::'.:;."'.,;:
.. P
"'~·";""I\.','-:':~i:".
·~S·.~:.;i::t::·::
l·e it/i~:
· J5".~·.~.,.:.
':,.
·;'ct{';"'·
...
.
No rna l ly a b r i ckwo r
J)4 rnrnt h i ck nota ina
:';.~~},
'fi::f1b,?J;f" ~,;..
l
í
í
ê
appr
r
a
g
r
• •
.•
.'
.
~
..
.~;'
".;....
:'.:
í
í
í
>.:;f.~,:",.~,~;c~) coefficient
.;~~~?~r:;J:
'.
'2
Lí n ng s h a l I be not
Br i ck Li n i ng s no t Le s s than
76 rrm t h ck
are permissible
for çhimneys not more than
760 mm in internaI
diameter, by agreer::ent
between the parti25 concerned.
NOTE.
s c las s of Lí n ing has arelatl.vely
10'.01
of exp an s ion (see BS 4207)
a nd '..'ouIO
· .:~"!~::~t'},,,~~.
cover requirements
(a)
and (e) and , d ep e udi rg up.)n
:\,;i-''-{{~'íjJt·: : ..,. Th
:'.'
í
í
.'
~
~~
1ess t ha a
(se e note) and shall be t ak en
to the top of the c imney un1ess operating
conditions
are such that lining of the ~ho1e
C~\i~~2y li ~ot r~G~~red.
..
6.2.4
So.ud axeâe ,d.1.atomaceo Js concz-e t e , Th e
aggregate
io~ so l d g r ade dia t.orna
ce ou s C0r'C r e ce i s
.
f t ".=..
~
,·....;-1L'S as t"'0:1n e b __c
r
k S men ,..:
,").-1
.0
.._ scu....oe ~te
__
.. _...I"t.:
•.•.
"abovr::
in
op i c e
ad i ng s , arte. i s ra xe d ·t..'i.th
high a luraina cement. The coric r r t e can be p re ca s t
Ln s h ape s .as required, ca s t insitu
o r p l ac ed by
• the "gunn ng ' processo
t
...;
6.3.3 tsr i cawo rk ; Sn a p ed b r i.ck s shall be used f o r
chimneys up to ~ m :~ interna1 dianeter, or wnen
necessary
to meet the service requirements,
aod
the general contour of lhe brickwork
shal1
co r r e sportd w i t h the cu rva t u re af the ch i mne y
shel1. Joints shall be properly fil1ed and shall
1.:Je a s ~h:':-: .:1:1 po s s i c l e , :~c:-tar sh a l l no t b e
placed b~t~een ehe bcicks and the ateei iheil, anci
there shail be no cavity between them and the
shell.
~}::
,.~
"
~i.~
~~.
6.3.4 Supp:Jr=ing r i nç s ; \,nere sup po r t i ng r i n gs a re
used, the first course of brick above each ri;'\g
;:;
7
>~:
..
A
.~
1978
.,
:..:i
j
.:.:
oain': ~in t:;~ t empe r a t u r e of the
nne r surface
of
t'" -: ch i r.; ..::.:, ab o ..'~~ t~f: ac i d I·~~·" p o ín c u.~Cp.t" nO:':::i.:.l
':i'E:~a~ ~:lg ..:,)a<i~t: ..;:-.;.
shall
project
at least
10 ~,
so as to protect
the
~ing and allo~
any condenia:e
~o falI clear of t~~
." . .'!ir.i.ng b e Lcv , .l~~ s ze e l r::-::; s .ia l L ex:er.d i.n-...
·at..!
tliiit·.from t he shell
50 as
to r e a ch at least
0.6 t imes
;;i~f:the thickness
of the 'l n ng ,
.
í
:rt'.-"··.
.
';,;".6.3.5
Openin-;s. Ope n í.ng s for flue and acc e s s d.ao r s
" 'into
"t he ch crie y lining
s ne l l De p r op e r Ly f o r.ae d
~ith arches or suitable
sup?or~s to soffits.
fhresholds,
h e ad s a nd jazes
s a a l l, be su c cc l y
insulated
to ?revent
deteriçra~ion.
í
í
6.3.6 Conical base sections_
Ir. chi~~eys having
·0' conical
base se~~ion,
the li~i~i in such secticn
'should be rio t less than 229 =:::1 t h ick as f ar up a..
, ia p r.ac t.Lcab Le : t h e internal
d i azie t e r wiU
:;i-?normally
be equal to t ha t o: t ae lini:lg
above , The
.i.;-\'~ space bet·..,eer. che lining
an d t'~e s t e e L shell
sha L
í
í
~W~~'jé'::(b) loIeak coric r e t e (e.g.
~:"""J'"
':f
~.
•
.•~<~/rubble.
or
,';/{<.f.-,,- •. >•....
b e tve en 8 and 10 to
aggregate
such as br~ck
1)
It should be appreciated
thaC, however effective
the
ns u l a t i.on , i f the flue gas entry temperature
is too low, condensation
and acidic
corrosion
will
take place.
.
i,:t,':j',)~:'(C) â'suitable
comb Lna t í.on
(a)
of
and (b).
enâ insula tine; concrete lining.
>>'Xlt' is not ge a e r a lLy pr ac t i c ab l e to line ch itnne y s
·j;;?·of less
than I m shell
d Lane t e r with b r ckwor k o r
.".:) gunned Li.rring s af t e r e~ection;
in s uch cases
./:,"':'castab le refractory
mí xe s of va r ous compos i tions
. "~.i);,,may. be used
A number or insularion
fall basically
7.2 to 7.5 .
í
.,:
into
~ethods may be used which
toe four types described
in
7.2 Aluminium cladding.
Aluminium claddl:-tg* is an
effective
form of insulation
because of its high
therinal reflect i vi t y , and i c. shall be app l e d as
stated
b e l ov ,
í
'·~jfi··'
-
í
linings
shell
be se cur e d to the chimney
?:;-:,:shéll by a su i t ab Le ancho r ag e , Such anchorage may
?f~'con s s c of s t e e 1 raesh , (se e ss 405 and BS 1485),
'~;cconcentric
~ith the shell,
fixed by su??orts
'/ . ·,.;elded to t he s h e Ll, at ap pr ox i tia ce Ly 600
·{:;·centrest
or of mus h ro cm o r Y-shaped s t ud s at ab cut
<{~f450
cent r e s , The Lí.n ng shall provide
not less
::;;,'than 25 tmI of cover to ali rae sh and s tudi.. . .
~~
~~
,
:'Í
.~
~~'
..•.~
o,;
.:;;
,i~
.~
]
.i~
]
=
=
(b) The cladding
shall
cou s s t of a Lurninium
sheet,
Erom grade ~S3 to grade H4 as specif{ed
in
BS 1470:
1972 not l e s s t h an 1.6=
thick with
symnetrical
flaage
covers made in halves frem
~S3 or SI grade aluminium sheet
as specified
to
BS IL'70: 1972 wh ch a I s o shall no t be less than
1.6
thick.
í
;\:~~Thelining
may be appl í.ed w t h the cb í.mn ey s:h'ell
a horizontal
po s i t on , toe latter
being ro::â\'~>i
/:~: dur ng fo rmi.ng , if desired,
t o a vo i.d the
us e tof
,t~;:shuttering
(see IlS 4207).
á'~*
~.
i
-
~~
1
.\~
-:'.{.'f,
.'{
:,
í
í
=
.::f::If>linings
are applied
bythe
"gunn ng ' pr o ce s s
·.:;::.:,they.'shall be secured
n a manne r similar
to .that
!;:?: described for c as t ab l e Lí.n ng s and shall be cured
:óY'after
applicat
on as r ecommended by t he
"";'.
;·i$.:;t}?~n~tact.urer •
í
",:õ:
~
..
..
'.j..
~;'L
j~
.~
.~
J
í
(c) The cladding
shall
be rnade in strakes,
using
a n~~ber of equal plates
par strake.
Aii seams
shall
be connected
by aluminium allay
rivets
at
not more than 100 mm centres.
Vertical
seams of
each strake
shall be set a~ tha midi'oint
Df tne
strake
beneath.
í
í
-
-,
í
·i~~~'··:':>:~:·~F
-.~-.' :,~:~".'
'J'~':7.;~EXTERÍOR I:\SL1.ATIO~
.~
.
'.,~for w ind 'I oa.i c a Lcu l u t ion s , ::,,, ch irariey diaz:etar)
':~;;J.:5hali'be t ake n ove r a11 the c xt e r na l c l add i ng , For
)i.. aec t i.on mo du Lus , D s aa l l, be me as u re d over t h e
/bf:',
1. sue
1..
11 •
.~<~:stee
(d)The
claddin;
shalI be fitted
with its
nr er na l face 6 ",!TI a'.~a:; f r om t he e x t e r na l f ac e
o f the ch i zan e y shell,
or a s ne a r as po s s b l e to
clear
rivet
heads in the s:eel
she11, this
distance being ~2intai~~d tly conti~uo~s
c i r cumf e rc a c i a I s p ace r s o ; .) mm t n í.ck asbestos
tape coincident
with the hurizontal
joints
of
the a l umi n ium, Th e asbestos
tape shall
be
cemented into p c s i t on by ne an s o f s od i um
silicate
ar ath~r suitable
adhesive.
The ends
of the horizontal
rivets
i~ the aluminium sheets
serve to retain
the asbest05
tape in positian
aiter
erection.
The circu~Eerential
asbestos
s pac e r c -,i:"'Jide
r.he 6 ;;-.mi'.irspace
oet'"Jeea t ne
s t e e I ando t he a l umí n ium i nt o sections
no t more
than 1.5 ~ apart,
thus reducing
convection
heat
losses.
.: It has been f o und from cb se rvat i.on and
:~calculations
that the effectiveness
of insul~tion
"{,is
as shovn in t ab l e 3. It ia essential
that :the
.1:·grade of insuIation"
selected
is Buitabl,:
to "i .
(e) I-i'hen the Leug t h of t h e s e c t icn s of shell
between fLanges i~ not a whole cultiple
of tha
strake
w i.d t h , ou l y oue make+up s t r ake pe r
section
Qf... chimney shall
be used.
.'
General.
Ln order
to mi n i n iza l.o s s of he at
. :~ from a chimney and to maintain
the temperature
of
.',~ th~ steel
sheIl
above the acid dew point leveI,
.k:.externalinsulation
may be f i t t e d ,
'.':,:'.'7.1
;;}t;':.'
.:
t.
í
í
;'!:.'
,
e f f e c t i.verie s s of
~. ,,:'. (a). the
',' ,," (b ) the ve Loc i t y of the
··~r·~·.:.···(c)the
'::-; .•C- '. : '; ;.:,
inlet
temperature
-. :.
.
t
ae
flue
of
í
nsu l a t on ;
gas e s ;
flue
gases
,
-'
v
~~;i;~~W0.~
::;"',:,:
,;;::!::..~.·.~Sheet 'steel
".
ar other
:.•. :»
!;:~~,',,'
~",
.
.$$
." I.
.:.~:~~4.~~~;~:;:":'."<1'!_~:'~!/
.
forros of cladd~ng 'm.ay be sUl.table
,~
1~
.,
.~
...'
:~
'f~:
,.
_;1'
'jj
(:~
.;::~;~.
~n c.ertaln
cases.
,4'"
-~j
:.;r't;
.~,t~
..~~
t~~
t~
';f1
"~
~;
.I\:~~!
..
~ ~
. "',;%';.5 ~.
.,.".'~
'~~1~~~:;~:)N;};,:.-··
..R?:
.~
í
í
the
.~
í
o i i nsu La t cn r ec ui r ed to ma nt ai n thê
;~~rterilperature'
o f flue
g as e s vab ov e the acid d~{( po n ;
,:,::~~depends upon:
'
í
.1
í
.'
·:;~~·.:Thêamounc
~
".
í
in
í
',::
--1':-:
(a) The exterior
of the steel
shell
shall be
treated
as described
in clause 8, using a goo~
quality
heat re s i s t i ng a l utai rri urn p a in t (s e e
BS 5493).
í
..<;.
.,;
í
~,:n6~3'.7 Refractor'j
.;;i; ..Caatable
'.~;
~n
•
stable
't-;
í
~1I~í;;::~~~:;"fille~W1;:o:
;'~~'::.~,
'(a) br ckvork ; or
~ff~f·~u.~ng
a heat
~',
Th~ velocity
of the flue gases shall be as high as
: ~acticable
to ensure [heir
rapid passage
through
:he length of the chicney.
ldeally,
the velocity
·;hould. not fall b e Iow 4.5 isl s when unde r light
load, but a 10wer velocicy
is sometim~s
unavoidable.
If tne velocity
of the gases is too
lc~ they will not co~pletel;
fil1
the bore at the
tO? ai the chim:l~y, cold al[ ~ill
e:1ter ort the
wind~ard side, d~scend t~e ctlimney
for some
distance
and thu, cool the surfare
of the chi~n~y
to below acid dew point.
This effect
is known as
'cold a i r inve r s ion ' and ::Jay be o ve r corne by
f t t in g a t op cone to tn2 ch imney (see 3.37).
It should also be recognized
that gas velocities
above about 35 m/s may creace problems due to
acoustic
effects
but these are outside
the scope
of this standard.
í
í
~á .,
-'?' .'
8
""1"'\,
-.>,
..~." ...
.
._,.~,.,.,.
~r
,'~.<~-~~." '~~~"-~:--~":"'?"~~<~-"'
..:-''''''
,.;~~
.:..~
~~::m1
..v;
B5 4076:
1978
;J.;}~:~t~·~~~t.F·
::":'.
l'
3.
I>iSL1.ATIO~
(f) All projections' shall ~c c l a:..·•.Clcani:1g
doo~s and other points ~~_ce a:~ess i5 rcquired
sha I L Je ''Jcxed ia' '..rj' .. ,re;-··v ab Le, a l ;.":l1i :1 ~~::J
TASLE
pane 15.
ins\.,;lation
TY;Je of
I
VALL'ES
l'h i·::~c·~e
S3
Overal ..av~=ag~
U valuL5
.I
(g) The air space ~~ :t-:. ch imney t e rta na I shall
.be corap Le t e Ly se e l ed t, pre~ent ingress oi
rnoisture betwe~~ tha s r.e e L shell.and toe
cladàing.
Al\.:I:\iniu:n
.,.
(j) To p
it
t i
f coe
t
of toe
·.lÍthou': ecov í.ng toe
i ng ,
150
r:=i square cpen
c g s , Lo c ac e d at c ar e f u l l y
selecced points anc co var ed by removable
p ana Ls
app r ox iraat e Ly 230 = square, snàll be p r o ví de d ,
..... Su i t ab l e po s t i.ons
'are:
e
rtn
axami.n
ch.í
a
on
mney
o
s
r
e
el,
s
c
ue
Lad
l
app r ox i rca t e Iy
1.25
n~~f.:~~~~~.::-:
.:~ch iciaey ,
t«I-..::_'::
-,:·
v~
ere7:lo:1, t
c
and p a i at e d v ch a c l e ar Lacque
A:~er
'(k)
",~
he
may be
ng
de
g
r
e
as
:<
"
-~
I
I 1.15
I 0.7
50 rnm
7') mm
100 mm
.,
0.5
...•
.:
150 mm
~~
.~.~
0.35
',~
e
a
Rí
ve
re
a
no
ac
7.5.1
The rnu l t i+f Iue c h i tan ey i s ar. e f f e c c ve
me t hod of na i.n t a i n i ng the ve l o c i t y o f the flue
gases at various operating
levels and oÍ providing
adequa te insulation.
í
7.5.2 The liners ir. a mu l t i+f Lue chimney may b e
contained
in a 5tructural
shell of steel, brickor
reinforced
concrete,
in a shaft within the
structure of a buiIding or in ar. open str~ctural
load-bearing
frame buile from steel sections or
reinforced
concrete. Sormally,
each liner is
connected
to one combustian
unit so that "he
optimum gas velocity can be achieved{n
alI
operating
conditions.
ce
(n) G~ea~ care shall be takea to ensure cnac
.dissi:n:lar met a Ls do no t come into ccn t ac r w t h
eaco orner. l~ ie is essential
iu the design
that t~o dissimilar ce:al~ have to be conneceed,
a su i t ab l.e non+conduc c ive and wa t e r+i mpe r v ious
filo or agent shall be placed between ehe::l.
•...:
'.
í
7.5.3 The "emperatare
af ehe inner surEaee oÍ the
liner can be maintained
either by wrapping the
exterior of the Iiner with a mineral wool mattress
or by filling toe space between the liners and
'ehe structural
shell with an expanded mineral, or
both.
7:3 Mi~aral wool ins~lacion. Wrapping the steel
.shel1 with a suitable grad; cf mineral wocL fib~e
insulacing
material ar sufÍicient
thicknes~
'provides more effeccive
insulacion
tha:1 al~"ini\.:~
cladding wien the usual 6 ~ air gap. Thicknesses
oÍ over 50
are ap?lied ir: ::wo separate
layers,
the ou:er layer bein~ f~tted so that the ~~rtical
an d ho r i zo n t a l, j o in ts 2.;:~ s t a ag e r ed f r om ~:~~
joints o i t he inner ..:2}'c:r. Lf the angle j, . n c i ng
.
flanga of the chimne~ ~.ction p~ojects pas: ~he
, .....i(:<{-~·'1)~·;·· out e r f a ce af
t he
mí r.e r a l \"'001 ~ i t s h a l I ;.,!
}\f.~i,;Ü:(~·' ,wrapped wi t h an add t io n a l Lay e r of mí u e r.: l '·Jol
,>{O',i.':',,::.·.'
of the
t h i ckne s
ror at least 75
·:':}7i:;:i~s~~:~:c
.side
f the f l ange j i t , As
r a I 1.'001h
to
?·1),·J~';:~~t~~\::
b e p r c t ec t e d f.,.,jl"":'l -I"":' ~'::\3."'r.e':'" ::I convan
e-:: "a" of
;.J~:1:~
..~~t!~"
, ..
"'-:,-;~
. _.'~ .•\'.:: ~~rL.:._.I'~ .~.
-»: .•.
i,.~~,,,:,~,-,..es-. .. do i ng c a i s 1.5 to cove r i t .atn an a.i um i ni; ....
':~~:l:{' ·,tI.:.tt\~~l,!l~~·~..
.'
_.
..••
..
•
)l:!.~i;:~;::'.r!:r:~~
... c l add.i ng as de s c r i.be d 1n 1.2 but omr t t 1ng t ne a i, r
.;
..
í
,t;:·~../-;.
~ T•• ~;.~~ ••
0.5
'.:
7 • 5 :-lu 1 ti- ;:1ue ch it:L'l. e y
i!~r.
"I'
[00 rnrn
101001
r ,
í
e
\~.;'-
0.7
Expanded
mi ner a I
ed
The alu:ninium c l add i ng raay be app l e J o n
s t e e i che r be fo r e o r af c e r coe chir:mel" i s
erec~ed, o r at the ::la:1u:act\.:rer'
s work~,. If toe
aluxinium
is applied ae works or on site before
erec~ion,
greac care shall De taken not to
damage ~he al~inic~
sneets. lf a sheet becomes
d ama g e d , i: sb al l b e r ezove d and r ep Lac e d v i t h
a ne .•: s
t ,
t i ag
a p a t ch of a l umí n i uo over
the d araag d
is
t
p t ab Le ,
he
~[.~.
í
dd
75 rnm
Exp and ed
mineral
the top o f che
(m)
. ~·:;:.t:{:·,
~,
La
í
:~~k'u,:":'~"
'
m froo
~lineral wool
Exp and e d
mi ne rai
·.·!·~~5f;:~""'"
:.~~.~
'.t~!Wb~;;,t'·
.','-(2)
1.15
Expanded
mineral
any inle t;
o ppo s i, te
2.3
~[ineral
í
diametri cally
(1)
25 mrn
50 rnm
1,1001
".5
to
2.6 to 4.0
L
d
í
;;i~:.;.'h,~i~~·
3.4
18 mm air gap
:Iineral wc o l
~ineral
=.
.
6 rnrn ai r gap
Aluminium
(h) Each u??er .,~rake of a Iuni.n ium s ha l I la p
·.over toe lo~er straka oy a cinimuc of 25 ~ •
.The vertical
seams s i taí Lar l y sha l l h ave
a
::'
..'mnbum
lap of 25
'
•
W/(m2K)
í
:'
.,
=
7.5.4 I,nen a granular material is used as an
insulant te is essent~al
thae a gata valve be
provided f~= its r~~0~al and that a noeice be
affixed n~jdcent
to l!le gatc valve ~arning af the
cangers o[ o?eration
hy unauthorized
personnel.
í
s
arae
s
c
o
rnm
n
raí
,'"
ne
.a
a
í
7.5.5 lf liners are ~upported by an open
structural
frame, it is essentia!
thac they are
adequaeely
insulated
and ~roeected
from the
weacher. Suica61a ~ethods are outlined .ia 7.2 and
ch
s
>:
;;r-'5~~1C~:'7.4
8.
Doub le skin chí m.ie y, The sp a ce b e t we e n t he
outer s a e l I and the Li n er of a doub Le sk i. cu imnev
;:~'\",.:.),;<. can b e filled wit:h mineral \01001, exp an de d mi:\eral',
/(:.;:'-;-"/:'
..or o t o e r suitable Lns u lat o r , Un Ie s s a s ne c i a l
.!·.:~':'~~~~:~:~T;>·:':
he at+r e s s t í.ng s c ee l i s used f o r t:h~ 'li~eLJ
:h~
·.Y:'::>k~';::·/: temperature Tí.mí t at cn of 4.3.3.\
applies.
:<,::<':{:">
TRE ..•••
T~!E~nS
í
í
:,..
It is essential
that there shall be no me ca l to
• '"..::,. metal contact be twee n t he liner and the o c t e r
(Ií~~":'::' . shell, oth~rwise "co Ld spots'.occur on t he l~ner,'
~(~
:"':':
t.hus r ed uc i-ng local a re a s to be!·.)W the a c te uew
'/~..:.;.l~~~'
.. point Le ve L and Íacilitating
ae'idic candensation
':.u
~.:-l~.:
." •
•
and co r r c s i.on ,
t"
'i:--(-.J
PROTECTIVE
8.1 ;urfaC".~.pr-eparation fo!:'Eaint tre_a.trr.";2l.
Cons~deraL_on
should Ge given to the surface
prepa~atioi1 and protective
treatrnent of both th2
exterior a ad i nt e rio r s ur f ace s o f ch mne y she l ls
in arder to prolong the life anJ improve toe
appearance
of the chimney. lmmediately
before
app Ly i rig any protective
t re a t me n t; to the exterior
or the interior s ur f a ca of a s t ee l ch imn e y shell,
the surface shall be cleaned by chipping, scraping
and w re o rus h iug , o r by other me an s , to remove
alI dirt, 1005e scaIe, greas~, rust or other
delet-erious materials.
í
.·~i."'~;~·..:i~·~
..·Z v
.'"
7.3.
t't.l·1.~1!;·~,~~~;
:;:~
..
",jf:' ';1"";10 .i~. ".' gap ,
I-
.~i
í
••..•
f,\:~;J~~~:~>:"
,:~~t~1it+:··· :',:;
·:'1·'
., .~.
~~J{:.·;i.J~~J~:~
-
'~(~~~~~]1?":
.'
."';;':~'·/.'f,.""'t..-.,.•••.•..
.,...•..,·•.,
9
..
_ ...~
l':'~?
', ...'
~.~-~
;-;,;
'~':~'C'li..,~~';...;..:t:;~:
.',
:.:f';'?8';2
;":\,.,'
'.':'!..'.,
','~·8.,_.1
,,~~'
':: 110
I;'ainti,,;;
of interior
5ur':aces
..'
. i~: ;
1
l
chJ.:~J1e:J
a dv an t a g e in app l y ng
un
i.neá
s
ae
.1
í
;;;.::~:~,~~~ ~~t~:i~r.,
·_~:~t~r-~.•,.~.~_e>.~ .-
,-'-=. .•
•
There
r s gene r a l l y
p r o t e c t i ve treat:::e~~: to
~~h~:~:
S.;'~ I
s~~f~:e ..~f _.:~. "n,l:~e~
:>I~Q"
0_
••.
_.,.,;.
-
'; ...••..•..•• '-. •...•...3. _. __
i
•.• ..1,._.
.,0.-
·.,,{\~,Cwithstand
t oe cor rc s i ve , ab r a s ve ar.d t he rna l
'~~Y~F>effects o f t he flue g as e s an d thus prolong r:'.':
,<""., , Li f
f t h e ch imne
.
}~:,~,,::.
1. e. o
y,
the bond in contiguous
are as. Minor a~eas
dac~~~ ~ny be reetified
by the applic~tion
< .• t ab
i c a l um.i n i ura paint
a f t e r c l e an in g ,
of
of a
i i he-t
':)t'
r ay e d ,.:"··i·:-:i"'.';~ys
~e .uf u~itGr:~ sna~i[:g 0~ C~X~t;re.
Th,.
r
n
s
ap~)~a!":l~~CC;
s
f
::;l::
p
í
8.4.2 Sp~cifications.
,:,;~::;~~.".
8~2. 2 Lined c.'limne:; sbal
Ls , '..r.1eni ~is t;'.oug:-.r
:;.>,:,.:·,desirable
to use a p rot e c t i v e t re a ttae n t ori .'
·':·'.'·:."interior
s t e e l s ur f ace of a 1 i n ed ch an=;", sue"
". treattnent
shall
cons i s c o: c::e appli.:a:ion
o f ::::~~
'.. coat of a s c c ab l e p r ia n g p a n t f o l l c:...•
ed by t·.·,)
#:~.,:.:.:;coats of a finishing
p aí n ; c r p a nt s , applied
i ::
"1t~::.accordance
w i t h the
ins t r cc t io as o f taa .
·.:~l;::<.Clanufaccurer of t he particular
p a n t s ••
ALI surface
prepôrations
anda1uminium
spraying
shall be in accordance
the requirements
of BS 2569:
í
í
í
í
(a) for
applies;
temperatures
up co 100°C,
Part
1
(o) ror
ap?lies.
t ernp e r a t u r e s ab ova
100°C,
Pare
2
with
'1
í
í
~~i(1(;'"
':i'~"~~~
8.2.3
,~,:i." ';,surface
,. s:~
Mult_-L.!.ue
"
•
-r~c'
:1-
1
-
.
c!urrney
s:~e41s ••
i nc e r a o r
5 r
t ur
shell
f a
t i+f
e
g i.ve
n
one co'ar o f a s u i t ab l e
in acco r d ance ,••i t h ~he Lns t ruc t i c ns
of
':/:.:i':,'chimney shall
.~;.. ' ·p~int.
applied
.y .'of the manu f a c t ur e r ,
che
c
o
uc
a
L
o
rcu
l
l
ue
Ee
Y~',0\
a
s
u
r
a
ce
sh
a
l
l
,
Ho'
••
e
ve
r
,
' ••. '.~
BS 2569 defines
metal coatings.
the
requirernents
for
8.4.3.2
It is essential
tr.ae the blast-cleaned
surface
i5 sufficiencly
rough and clea~ to provide
adequa te key for' the
p
d l
iura
ti
The amplitude
of t he b Las t+ c Le ane d p r o f i Le is no t
stated
in BS 25hY but the surfaces
produced by this
method have an ar.l?litude
oE 0.1
0.05 mm and this
is satisfactory,
s
r
ay
e
a
umi
n
c
o
a
ng
.
('
8.4.3.3
Compressed air for nozzle blast
cleaning'
shall be effectively
iree from oil and moisture.
The pressure
during the b l as t ng p r o c e s s s ha l I be
not less than 400 kPa at the nozzle.·
í
··~/':(·,S.3 l'ainting
of exterior
surfaces
}:Q}iS.3.1
Exposed steel
shells.
Irzne d i a t e Ly after
.:,';'J).',+thesurfacepreoaration
ouz l i ne d in 8. lhas
been
,:~t4rdcompleted.
t
~xteriorsurfaca
be g
a
,'\":i)·.coat of a s u i t ab Le p r í.mi.n g p a in t fo l l o:...•ed by o ne
coat of f i n i sh iag p a n t ap p l í.e d in ac cc rdan ce with
V:'::,:.the reco=ndacions
of the n:a~uÍacturers
of the
:\':: particular
paints.A
final
co a c of p a i n t; s~ll
be
~:~;"~applied
a f t e r erection.
he
sh
':;:>~~>
a
Ll
í
t
ti
should
;:J3Íd to t
'~1'~portion
of the exterior
surface,
e.g. from a
distance
of 1 to 2 ch mney d i ame t.e r s dcvn from the
i,: ·to.P. where o n Ly those p ro t e c t ve treatments
sh ou l d
.,; be applied which are best able to withstand
tne
corrosive
action
OÍ tne ecerging
flue gases.
Spe
c
í
a
l
at
e
n
on
b
<:....
e
h
e
uppe
r
í
í
S.3.2 Shell with extern~l
cladding.
external
clad~ing
shall
com?!y with
·~·::·.where the cLadd
ng or insulation
is
,1Ú;;';,i·works. in wh i ch case the final
coa t
be omi t ted.
í
!tJ;(~
Shells
with
8.3.1 except
fitted
ato t h e
of paint may
·;~;j,~8~3.~
Multi-flue
..:..:,\.
,
.,'.
'::if.~':.s-.4'
Metal
y;o.o ",. :')
~
spr ap
.
r
e
a
n
s
c
r
í.be
Cxi
..
í
8.4.4.2
For shell
temperatures
exceedi~g
2üC Cc
the a l.urni.ni um co a t í.ng s h a l I no rma LLy ue app Li e d
by the eleccric
arc processo
The flame spr2ying
process
nay be used if the chimney is not Co be ,
j
t
to temperatures
i
550°C and/or
t ne rma l shock* •
sub
e
c
e
d
e
xce
e
d
ng
The spray shall
b~ sealed
with a suitable
s í.Li con e+b a s ed h ig h t e mpe r a t ur e p a n t , applied
í
a
f Lco
d
as
c o a t ,
(
8;4.4.3 lha
nominal thicknes5
of the coacing shall
comp Ly w i t h t he r e qu i r emen t s of AI 7 (0.18 mra ,
0.007 in) of c l ause 5, BS 2563: Part I: 1964.
nj
r
ay
e
a
Lum
.~
.~
n
,.
í
í
ed
of a steel
ch i.mn ey
cb e r i c cor ro s on by
r.e
tal co a t ng ,
:-::~tal for t h s
ne t a l s have
t s
f
í
í
frt
í
h
o
ur
a
ce
s
,
)
'\:':The 'i~itial
metal spray t r e a t raent; sh a l L be "'-,
applied
und e r controlled
co nd i tions before'
:,.;;.:erection
and c ar e s ha l I be t ak en to avo id d amage
:;:'i:~:-during
t r an so o r t a t i on
and
e r ecc i on ,
~;~\~/
•. ~ . ','
".
.
.
:.J"·.'. Reg i ons of d amaga where the co at ng h as been
'!>(j::removed ove r a n ar e a , tha rnax iraumw i d th o f vh i ch
-"~:::':exceeds 6
shall
be r eb I as t e d and r e sp r aye d ,
,,·~,:\cai.-e bei.ng t as e n to avo í.d d amagi ng ar loosening
.,~<,
o
••
í
=.
:;li~1i:~;;M~~L,
.
of
8.4.4.1
For she1l temperatures
up to 200°C the
a Lum i n i.um spray shall
be ap p l e d by Lhe electric
arc ar f1ame spraying
processo
s
na
;;k;·;.'S.4.1 General.
The exterior
?k';;:',may',be protected
from at nos
·;,-;:.,.:::heapp Lí c a c i on
c i a s p r ay e:
\,/')Aluminium
s che prefe~red
'·:f.;app1ication.
(Certain
other
Fo:,,,; disadvantages
·.... e n us
for
h
and sealing
8.4.4.4
Sealing coats. The p
d
i i urn
coating
shall De ~ealeJ.
for temperacur~s
not
exceeding
150°C,
certair.
crga:'lic base sealers
ar
pair.ts
are suitablc.
Special
high tem?erature
resistant
paints
shall bc sclected
for use at
t erap e r az u r e s e xc e e d ng
ISO °C. e.g.
r c s i.n -mo d i f i e d
silicone
base paints.
Silicone
base paints
shall
be used accordirlg to the ~a~:.!factu~er's
i:1structions.
cl1imney frar.:e:,'Ork. \oihe~e' á
r~~~.!';i;.ft'a.~ewor:;..
~orr.ls t he supp o r't i n ; s t ruc r ur e o f ' a
",1j:'multi-flue
ch i
the t
t me t; de
.::., ~.3.1.shall
be applied.·
,
mney
8.4.4 f.1ethods of application
coatings
í.ven
.->.!
{:,:'
8.4.3.1
sprayed
=
to
í
;",,0'
St.:rface p t e pe r atii on
an
.r;!::,':';S.2.4 Chlmney siie LLs: wi: th :::0:;01 i tl'li c linings.
,''i;\;;\interior
s t e a I surface
of a cb zney wh i ch is
be gi ven a nonoli ch í,c l i.n i ng ne e d s no further
-::·:;.';,;;;·pr.:;)tective t
tmen t , The
f
;~:;i\::be c1ean and dry i=ediatel:J
oe f or e the
:,:\3~:application
of the lining.
re
8.4.3
-~
8.4.4.5
Application
o E sea!.':'ng coats. Sealing
coats shall
be applied
to cl~an, dry surfaces.
Any
oi l , g r e a s e o r o t h e r c on t arai n ant s s h a Ll be r ernoved
by thoroughly
was~ing with t~inners
until
no
visible
traces
of contuminaclon
exist
and the
surface
shall
be aLlowed to dry for ac least
15 rni~ be~o=e ap~t~'ing t~e ~aating& S2al~~g coa~s
sr.a l L b e ap p Li.ed ue av i l y enough to produce a wet
appearance
and shall
be applied
in accordance
with
the ma:'lufacturer's
instructions.
The treatment
shall
be appllcd
at the treatment
contractor's
works as soon as is practicable
afcer spraying.
".;./t.
'
r , ,'''~~'
y
':
...•.
':~
\S:
p r oducud by ga s t urb ne e:<hau~t.s ,
.:~~
í
'.:!81~:~2~~';;··~
•.~~;,_ -..-.....
....•...
10
~....
.,;.~"'.
..... ....~,.."_~~·_V"'-·
__ "".':I''''''~'''-'~'''''';.-.. ··•·.-...•-.-.--~.-·~.;·r.r-"r,~A..~....•..
':'",...~~~
•••I:.~,,"'~.t'".'õ-":l1",..~~
..••~~~~-,.
~.,~-
<":~
'i
.~!
.•i.
B$ 4076
!9 78.,~
§.i
t~
:''t,
~~
DIX
Ln
I:
s
p
selected
-=-: IO)j·
l~~S?E
A.!
ri.
e
c
í
t
e
CG!::::0:"~~;' '...;. :.!t
•.:·3D -:I·!...~I~;:::,
:~,S_-:Z'
s r ecozraend e d ch at a11 chL-neys
d
'inspection
e r e c t i on ,
by
a
t
compe
should
e
n
t
p
rs
e
be abou:
on
th
anc
he
a
t
r
fir t
r.e
s
steel chimneys
should
be e xaraine d p r e f er ao Ly annua Ll y., and the
t h ckne s s of tne shell
de t e rtaí ned by e i t h e r
'ultrasonic
thickness
testing o-:-.by drill cescing.
í
flanges s~ould be inlpected
to qe~ if
a bu i Ld+up o : rus t b e cve en t he ra, as t he
o i: rus t b
c ar;
c:...
t
in tension. The rivec heads 00 tue inter~or of
r ve re d ch icne ys sho u ld be e xani ned to as ce r t a n
:tha:: tney are secura a,d have not eroded te a
'dangerJus
degr~e.
u
r
e
u
í
lc.-up
ove
r
l
o
ad
e
b
í
o
l
d
s
í
.A.S For li~ed
~:d i~sulated
chi~eys
it ~s
adv i s ab le to c ar ry out ao e xaziína t i on as ab ove a~
t h re e+y e a r Ly Ln t e rv a l s subsequent:: to t h e f rs t
eXa8i~ation.
~ined chi=neys
should also be
Lns pe c ced internall:; by cLo s e e xamí.n a t i c a f rom
a bosu~'s chair, or siwilar means of support, tO
as ce r t a in t h at the ~i:ü~g
s still in s e rvi ce ab l e
con c c i on an d fulfi Ll n g its t ask ,
snd fi=ti~iS,
~here Present,
should
be e):anined for securi:y
and tension and, if
~ne ce s sa ry , be cLe an e d an d gr e as e d,
OSCILU,TlO;';S
. B.I Ch i rnne y s a re s ub j e c t; to oscillation
o ue to
\;ind ac t ion , This 2?P2:1cii.x e xp la in s \.:hy
alter~ative
procedures
are suggested
ior making
an app rcp ri a t;e Lnc re a se in the de s gn Wi,Ld
Lo ac rig
and tO indica:e when strengthening
or the
incorporation
of devic2s for suppressing
Vo~
Kar!:lzi:t yp e o s c i ll ac i c ns is adv sab Le ,
í
í
ch imney s o f
ws
hcv
vo
e
she
dd
r.g
nat\Jral
frequ~ncy,
forcula
f, is:
for determining
th2
5üü(JD
b
D,)
Substituting
.B.I.3 The effect
v critical
:~
-'fi
H
.~~
.J,:.
)
..~
;~
;;
li.
''',i
~
>,
....•
,>~
:tl,
,':~
"
.~
this:
'i[~
.'\o,,~
w I
2500
S
D
(3D
b
t
I
~:*
- D )
t
j
mls
2
W' h
g
í
vhe r e :
h
B.I.4 Later~loscillation
due to resonance
effects
107ithin the critic~l wind speed range at the
natural period of a cylindrical
structure
may be
gr e a t ano ugh , when its e ff e c t isadded
ve c t o r i a l Ly
to t ne dcvn wind de r le c t ion , to cause s t re s se s
higher th~n those calculated
for the gust
velocities
in the code as static loading wi~h the
force factor in the scandard.
The calcul~tion
o f t he f ac co r C v l l p rcv de a gu í.de tu C:1E:
eout~ol likely to be requ~red.
The simplified
given in this appendix have bee;"l
í
s
.;~
t n e he i g ht;
of
Dt is the diameter
Db is the
11'
W
ch
ímney
.. ....,
(I n tn)
I<{~
at tO? (in m)
d i arnet e r at
:'~':.
'.,
b o t t orn (in m)
s t n e mas s p e r metre he i gh t at t op
lining or encasing,
if any (~n kg)
í
i8 the rnass per metreheight
s structural
shel1 excluding
,0
í
n c lud ing
ae top of
lining (ín kg~
:.('J
~:~
:1
í
f
s t h e natural
its foundations
í
f requen cy of the ch ínne y on
(in Hz )
.\~
.~~;1
.~;{
;~~
11
, ;:;.':i'~'i'
'~:\:I
,,),
1:
fi" 1
\/
r
, 2
ti
'j
of an extensive
jYste~ af
Ladd e rs , f r amewo rk , et c , at t ached to a c'lirr.:ley,·
may cause a ch arige o: t lov wh i.ch Ln c r e a s: s c he
a l on
g v
ad
dyn
amí
c
f o r ca
as
v,, ell
a5
s t at
~L
l o a d ,
,This
s :~=!n~ard' does íl.v:\~ co ve r such -eff.êc::,,;.
-
~:;i
a,
í
f
:':,
!l
SDtf
~
B.J.I An ~~proxirnatc
í
- -' .~\'J .
x
í
v cri~ica1
í
í
he
B.3 Ac co rd in g to t he o ry and experienee,
sevar e Von
Karman type 05cillation
is not likely if the
calculateJ
velocity,
known as 'the critical
Strou!1'.ll vc lo c i t y! , is g re at e r than the max izum
design v~locity.
The following
two fornulae
are
intended
to determi~e
the likelihood
of dangeroui
Von Karsan type oscillations.
The Strouhal
c r t i c a l ve lo c i t y for a circular
ch imn e y may b e
c a lc u la t e d f rorn the f o rraul a :
c i r cu la r
s t r cng ly a c ro s s vi nd
than alo~g wi~d. "It is chereEore reaso~a~)le to
co n t i n ue t he p r e s e n ; p r ac t c e vh ch i mpl i e s ch at;
a Lonz w ind os c Ll Lat L'J:1 \/i11 not c aus e s t res se s
at e r t:-lan t ho se c a l cu l a t e d for t ae gu,;t
,velocicies
n C? 3, (:1:i?Cer V, Part 2: ;;72 as
'stat::ic loading 107ith the force coefficient
proposed
in this standard.
í
e
í
·A.6 G~y ~i~e
I c nas b e en -L)u:-,.d t h a t
. cr o s s s e c t ion o sc l le t e more
n
B.2.2 In the present s t a te o f knowledge
t may Q~
accepted
that, even in the worst cases, a ehicr.ej
can be made safe by applying guys or strakes ar
any time after construction,
if experie:-lce shc~s
t he m to be t e qu i re d , and p ro v i d e d t h a t; t he chi=,ey
ia mada strong anaugo in the first place to
withstand
che additional
loae! from guys or strakes
applied later. Alternativas
are therefore
provided
in 4.1 (:1.) o f th i s s t anda rd ,
í
'B. I .2
re
í
í
í
Le
í
í
í
J
wind the regular vortex
shedding may be interfered
wiLh by fluctuation
of
t he Willâ, 50 that the b u i Ld+up o f a:nplitude is :10::
concinuous
as in a "índ tunnel, and it nay be wore
e f f e c t i ve l y r e s i s t e d b y na s s zad s r i f f ne s s , 1-:"1
i: r.
are.
if
t vi
as t ct
r t
i
s ho u ld be a l lowe d ror in p ra c ci c e , b u t i c is c le a r
that
10\<1 (j,..L'1'.;>Í:1g, ,:"."
ma s s and La r ge f le x i b i.Lit y
,
t!ust in c rc a sc t h e p ro b ab i Li.uy an d arnoun t of :;h-=
:;,
os.::illation of chim:l~ys. In many cases
the
j
behaviour
cannot be predicted with certainty.
It
~
is po s s í.bl.e to c a I cu la t e f r ora nf o rraat í.on available;d
t h a t some ch mn eys are likely
to oscillate
excessively, and others not. ln some cases the
o s c i Ll at i on '.-/i11be l imi t e d to sare amp l i t ude s
ii toere 1S a margin of strengch.
t he r e is
s
._~~
B.L.! In a natural
A.4 ~ngle
s
s t r-rc t ur es
í
A.3 At t he s ame t ze , any de co r at ve or o t h e r
s ur f a ce f í.n i sb 00 t h e exterior of the ch i raneys
raay b e e xami.ried , The i n te rn a I surface of l a rge
di ame t e r s t e e l ch imne ys may also be Lns p e ct e d ,
prefEra~ly
by close exa3ination-from
a b05un's
chair or si=Qlar ttea~5 of sup?ort.
e
te
í
í
r
app Iy
no':
e oi: ch i en ey
B.2 'c"ler ,ul ar fl uc t ua t i ng s i d e force due to ''';:\d t
is known o'; ~~~Kar::@an
vortelS._~he4.s!i..llL.
'w'hió
:~.ay bp
»duce d in 'a smooth a i r f low , will p ro duc e
sr'
.6 o s c í.Ll at ion at a ve Io c t y which
gives
_~sonance with the natuial frequency
of the
s t r uc t u re , Th i s effect
i s resisted by h gh d=;;i:"\g
an d raay b e p re ve n t e d by ho:::lical
st,!.§l~
or c t n e r
devices attached
to a circular
chi~ney.
rf the
tendency
LS strong, ~t is not efiectively withstood
by increese of strength alone.
one yeer after
í
-3.r'.. ':0
t yp
unc s ua l '. .j~or~ >,)(15, f o rra ot: cut Line , ~O=: zo a:-;~/
no t ~~o·.'.::ced
'~re~t
0:1. no rma I ly r i g i d f o und a t i.ons ,
A.2 t:n.i.nsulated and unlined
p
as s'..cab l o for the
'i;!
.;';'.
:~.!r!;
ij78
4075
....
:.'
...
.~
"
\
.;~~~;:r,:;,.:NC"::.
li
h
cne ch ítaney
a s a short cone at the t o p ,
u: are ali t c b e t ake n f·n the
"-:j'."'.,.""'.
....•• ,......•
..;. ..• '"
r::.-}.p
l..!_ .:l ••
4:.1: ..•..
:.,.;:·
.cy l 'di
n r.-C3._',:).::ap_ .. t: ~~'
O_l •...
W
0 .. 2,
- _.. _ C"
'~~-'''~.:::''''
"is 50 3\_;;~á
:':;a: ~:> i5;:--~,::.:e·::, t·:::..~:!. DI- + :i ~n.
.;.~
.. ~:~or-if 'a C0~e oi icclu~ed a~gle grea:er~than
JG~
.... '''ior.;:spar:
of t h e s t ruc t ur e , e xc ep t at t he
to p ,
Ú:;:;'~">the ab ove f o rtaul a ior f =ay be inaccurate anc
.b;'~:i';r.>shouldb e s ub s t i t u t e d b;: t he co r e detailed
.{~(;~;:~>calculaticn given
n :3.3.3.
,}l' . ,t~~:::·Dt.
W and
C ••
í
\,:,~ ~rB.3.2
V c
t
e
t
ity
"
as defined in CP 3, Chapter ~: Pare 2, Vs =
V.S1-S:-S ,
s e v e r e os c Lla t i on
is
~!}p~io~~v'~l
a n d
l
'furcher calculation
is resui:ed.
r
í
í
c
a
I
x
ce
e
d
s
he
de
s
Lgn
ve
l
o
c
:10
í
~ ;
:;"/'
\,\
.~/t:!/OA./AL
V cr it
li
í
c a I
í
s
Le
::1an tr.ê
s s
de
s
í
gn
í
í
. 'l"',::~,~'C
-
O 6 + K
/{:~~<~:~~,;:::
-Ó,
'
1 -
+~:
"':;;?'\'<~ ir; .the
I
·
J
Dt
~i
~ "
•
b
ff
b e s ugg c s t e d : s t ud y o f
t
no
a
l
e
ay
s
e
e
e
c
t
f
>,
d.~:J.~et:i!r;;;.'-.:!
ive
,
Nv
~lciat .~~
l:t'-;s
si.;:~l.e
c
an
th", l ayo ..~ by <;, _..:ia1iscs
:esti~g ~ay ~. nece- .ary •
and wiri~ tunnel
te is k nown th at 10" ciamp in g ::\0 s t i f f ne s s
wil1 increase the magni:ude
~~ .~~illat{on
either
a l o ng o r a c ro s s wi nd i-l
.,;.>onseto fluctuating
••ind. This ty~2 Qi osc~lla::Lon will noe be
r e d uc e d b y t he a d d i t i o.: o!' s c ab i l i z e r s ,
B.3.5
xc
a
o
n
dre
Ll5t:O,
a
e
nt
r
e
o
r
B.3.7 The value, oE K in table 4 are based on a
logarithmicdarnping
value af 0 03 for alI we1ded
chimneys;
0.05 for welded chimneys with flanged
and bolted joinls; and 0.07 for alI bolted or
riveted ch i mney s , Where t h e lining of the ch i mne y
is like1y to increase the daoping,
the vaIue af
K may be reducec! by 0.5. If che 10g damping is
kncvn orcan
be estimated ',.;i::h
g r e a t e r accur
acy
,
a value of K interpolated
fro~ the table may be
used.
c a l cu Laz ed
í
í
the
í
í
·j7!~~{~i·is
:·c:!:~··,):·'· ".~_'.
f r om t
e _ and the o t aer
var a
•
a.s·:gl.ven
t
Ic~u1a
g
a
"~:::~:'~"':C.
that: is Le s s than l , Von Kartran t yp e
;·.>:/iciscillations
az e unlikely.
If C s be tveen 1 and
·;~;>:;·-.·I.-Sthe co Ll e c t e d information
i.nd ca c e s th at t h e
,,~<r>chi=ey lvill no t b e ove rs t r e s s ed , if in design,
.,':.:;;',::
the ve Lo ci t y used i s incre a s a d by mu l, t p lying i t
{',f;:;>by the
f ac t c r C whe n c a l.cu l a c ing
t he
..,i.ndp r e s su r e
>·~}··according to C? 3. Hcwe ve r , li: C is be twe e n 1.3
(·;,fl::..•.'-.,,-Iand 1.5 exces s ve os·cillat:'cn
c anno t be excluded
,~;""'and p r ov i s on for coe f t t i.ng o f stabilizers
or
soee o t he r c-ean s of ccn t r ol Li n g cs c i l.la t i on s ho u ld
be made , For v a Lue s oi C ab c ve 1.5 t he fitting o f
:(f.~~Xst:àbilizers o r o t ae r me ans o f preventing
·.;;:~~;/.6scilla1:ion
s hou i d b e unde r t aken du r ing
cons t ruc t on , The v aLue s o i C g i ve n abo ve app l y
,·;·i;;;;:·. to ch irnneys -.Jithin ext ens i ve t ovn ar industrial
1:f',:~··areas.
Lf C ha s a "alue ab o ve 1.3, a design for
. :~';"::the co nd i t i on ·.át~ s t ab i Li ze rs adde d shall be mad e
with the de s i gn ••ind force, •. Jichout increase by
y::.,.:- the .f act or C. but í.niacco rdence '.;i th 4.1 (d ) (!) an d
ab
l
4
svebo
6
ab
ov
e
,
I:::
h
í
Ls
_:
_
s
rve
s
va
Lue
o
r
í
í
í
í
:v..·
<:::;,'
The frequency
·,~ívi!~i~;,~5~,~:).::-·
.... __ '.
u;
con s t
'•.1.~
'.
1
"
[ .L ~i:<z
including
the 1ioing
grélvitational
(
-
acceleration
..
:j.',
:-1.
.}
s t rc s s e s ir: t:!('~ low~r
p a r t o f v.
l a r g e {;~c.:nel.:r~:-.. ;.: 3:t'.)ul\.1 Dê: avo d e d
the vertical
c h izin ey 9f
í
by providing
suf~icient
cücu:ilferential
stiffness
around the chimn~y at the top_ Chimneys having a
gross plate thickness of less than 1/300
of the
diarneter, if no t e Lf i ci.errtLy stiifened by a Lin i ng
or enc as i ng , s ho u lc ha ve s t f f en i ng r ng s ad d ed at
t hs top (ao d 101"'1"do'...
-n if ~'1a he i g h t i s more t h an
20 tines
tbe d i ame r c r ) , T~ê d i s t an c c apa r t or t h e
s c i t t e n i ng ~i.n6:i
6~';Olil(!
o e :':...Jt ::o;:e C~.u:l 1500
times ehe thickness of the shell and should be
substantial
enough to give a total circumferential
bending stiffness
at Ieast equivaIent
to that of a
uniform shell o f tb ickne s s 1/200 of the dia:neter •
3.0
t
2.5
"~'.all r í.vet e d
.I -
Chimneys wh i ch have a h i gh diameter/thickness
ratio may be subject to wind-generated
ovalling
oscillations
due t o a c i rcumf e ren t i a l Ly varying
and fluctuating
?reS5ure.
Besides causing
circumferential
b~nding str~s3es :his can increase
f.~..;n6ed and
:::~~;':'bolted
joints
"
B,4
3.5
,·:t:~··~~
''':0;Bolted r i.ve e d o r
e
.•..:,.;;.~
!(
:::!)::""A.l~ ..,elded
. ,>~~~~~·'.Welded
;~k~-~-'" . wich'
I. vl(x)
of a sectian
(in kg)
g i.s the rate af
(í n m/s')
W~L::';:' 01' K FOR DlU:.REN~
OF CONSTRUCTION
~:,t··.: -.----------
(:;)
lLTi
x ii the deflection
of the sarne section due tothe
force equal to gravity acting on its mass
no rma lly at the rnas s c en t re , \.·:tichthe base
fixed and che top free (in m)
_~ ._
.
ruc t i.on
f =
W is the mass
or covering
í
·;;,l:,;.
: of
...
·,;.··-·Type
.~
.',.;here
,>'..
. ,'0N·,·'TABLE
·;i;;.;r'.·:TYPES
"
. 3.3.8 Instead of thc appro~i~ate
formula for.
frequency given 3bov~a
more accurate formula m~y
be substitueed
as follows. The natural frequency,
first mode, for a chimney of varying diameter or
thickness can be calculated
by ~i"iding
the
chimney into a number af sections.
í
í
.~~>:
i.
0
d ef Le c t i c n at t he t op o f
:':BXi,_thechic:1ey :0= unit d í.s t r b ut.e d Lo ad ng of
:,;-,;,·Z,i>,:t kN/m%. Th s deflectico s h a Ll, be calculated on
f;'f?t"de!li~n t h ck ae s s alone ·.;i~hê),;t
including the
;<Z;~!(:~~~
.."'corrc3 ion a l t ovance ,
.;F/
:l;:;;c:J:,,;':'~a:·::l/:
~i~:i~~ uE s:~~il~~~rs i5 u;~3ily hemay
e
>;,:':'.>velocity, t.o e t e ndea cy to o s c l l ar e :;:ay be
·::::!/:';.'.=estir::ated
b:J a ma n Ly et::;:>i=ica1
fo:-:::u1a:
~~(.~\~0'
-: IIOD;
l'--
tha:~
8.3.6 IE d~vice.; to i~~=e:!~.eda~?ing ar reduce
wi~d
it t i
t he p t
ho l da
speciaIist
who rccon~ends
[hem should give
info~atio:1
as lO the naxic~
orag and li~e1ihood
of any dynamic increase for the purpose of designo
In any case the strength should not be less than
proposeci in this stanoerd •
•
" B.3.3
c Lc s e r
_."
í
lf
of chi:nneys or ocher :a11 5 ructures Io:hichmay
oscillate
excessively,
part cularly if they "
í
í
.B.3.4
For ca i nm e ys expo se d t o ·.;ind f rora the s e a ,
~- bJ' ri. Lak e , n ::a\:
coun t ry o r :.~ilc
o n expo s e d
rounded summits,
the vaiue oi C calcuiated
from
the formula at which Von Ka~=a~ oscillation
may
_.' océur,will
be 0.1 tO 0.2 l oi...
e r , The fo rraula wi11
." not·necessarily
app1y to pairs, files and groups
í
t,ft':\
~l&
o'
12
Ó: -,
.,~~.__:~-;;~;~it!iÃ~0:;~;;_~·.
__~~~ __ _. __.._~ .
.__
~_ _. ._.
:~',_~'-'~;~~':~xS{.~"t"im~~ff',,~fl'
...
-"':·~"'··~
·-.~!~~~~~t;~~t~·
o
••
_
_.
__
.'0_.
•
••
.......•...~~~"'l""'~t'f~;:~.-:
_
•
•
•
.•
.•
...
!7'.•r•. ol~.'~~:'*''E'}l~~.;"\oe~;;~~,~><?'
.•..
~i"?
• '-"-'.,.
' •.•
,~;;-.
:~
•.••;..•••• .....,;.,;
•••••••....•.
~-".".:~.,.;.;,
•. ~~-_
.• _-".,,j.,
,.
~_,-""':' •..•.••.
,~...,..:...~'r.J''''''''_
~'
',.
!
APPE~DlX
I~
FOR T:lI
l:SE OF S:Al:;LESSAc;r)
OTHER
.~
.
\\.~(.
J:,,~~;~:~i
At.:,.";,,
,'~T:~EL S
~=.~ In
v., J Sr a i a l e s s a..c
a l l c y 3::e215
.: 'J~;:" .:.::.ally
.u s e d i;t t:12 f ab r i c a t i cn o i ~ ,~l
ch~ ··.::cys wh e n toe
g i s e s are ai an e xt r e ce l v '66!'23"
:e na t ur e ar are
ac a t e mp e r a t u r e hi;he~'
~ha:: ' , "c.
; igh nickel
and c h rom i urn content
a l l oy s , The·se',.::~'.':;i'.t·,"
"~;:; very resistant
to ac i d a t t ack b u t; are
";':'-:",~,',:
co ns i d e r ab Ly more co s t l y than s t a i nl e s s s ce e L•.':" ..~";:;;.;·,
C.2 The use of the ~~rrect
gr~~~ of srainles~
s~eel
ca •• i nc r e as e ch e ~if", - - ....~ c h i r-ne y o v e t' and ab ov
t he
l f e e xp e c t a r... ~' v~ ~ilc
s t e e l , Al t hough
ir is
difiicult
to predict
~he i~cre~5~
in life, in
'genaral, stainle5s
steal ai the ~orr2C: grade
í
should
at
chimney.
leasc
double
the
eX?2c:ed
1i~e
of
a
C,3 From experie::ce
ir has bee~ fou~d that
of the
stainless
steels
in the 18/8 grJ~e, thc one ~hich
has tha DOst resistance
tO corrJ
io~ caused
by
fl ue g a s e 5,
i 5 3 165 I 6, as 5;:> e c i:' e à n BS I 449 : .
Pare 2: 1975. rl--; a l cc s t c e nc c a gr-ãG2 is 316512.
í
í
í
C.4 It should be noteà that stainLess
stee1
i5
norma1ly
supplied
in ics oi11
ftnish condition
which
is a :natt
líght grey colour
and 1S not
s upp Li.e d i n a pc Li sh e d "m i r rc r ' f n i s n , If a
mirror
finish
is required,
the cost
of po1i5hing
is high.
':«
"' :4~~~
r-a xí.mum ico r r o s í.on a t t a ck can'' be anticipated~',:/~:1'r'~~~:
,
....
.
I'
..,':,).'"':.1,,.,ln .•.t-,
t ne top
se c t i.on o; a c.u.mney or
1.:1e1:.
. .,: .'::'~"I-!\:.'~,>t:~"i:.:
C
RECO~'.E:;DAT10:-;S
í
t.S
Because
of the
no rma Ll y on1y
high cose
i t is
of
scainless
us e d in po s c ons
í
í
cases
of vcr
c
.,·):,:s'i.de:-ac.ion
s
ho
y
L;:;
'cc r r o s iv>
gi',n~:l t
t.il...:
:'' ;
o
.
e
ci
e.
.'
s
e
e
l
,
tha
í
r
r
e
s
s
c
ance
í
ac
d
at
cack
;'y .'
..
,.
..~!
.,,
.1 .~ .
..;.-
o_o _
'\~_
•••
:
' •••
:'.~,<
. ,~
.~'.,
I·.·.·
J1"'
•
....•....
.'
.. - ..
l',
•••
1.,-
f'
./
r .
-~':;..;;~
...;..
':,r:.~.r·'
"
i(
/-.
'-:-,:".;
í
,-.i, .
.'
~h~.;.\;">;:~:~".;,~.:·
C.7 It has b ee n f cund f rcm. axpe:ience
thar;thelow::~:!,
co ppe r alloy
steels
have a coris i.d e r ab Ly greater::.::.:,.'~;'~';.
resistance
to atmospheric
co r ro s í.on t h an mild ';'.~"c.f~·;:·
t
but
i
to
r e su l t ng f r orn the condans a c i on o f flue
gases
is' ..
a o ou t; t he
s ame
as t h a t of zai.Ld
s cee l ,
.
.".,,~:.:.
~. '•.,q.': i:".:
( .8 For chimneys
t ha c '.rill
be su b j e c r; to aI:lbierit :'.'.'~~(.i ir
t erap e r a t u r e be l cv -10°C
for
10["6
pariods.,it
..:,~:~:
; s r e c onme nded
that
lc..•.
t emp e r a t ur e a l l oy steels
~; ~"":';
.:.,, us e d , The p r op e ré i,,~. of these
s t e e Ls C\U1 be ~.;;~:'~'-::'_.
.:;scertainedfl'om·'th(!
steel
manuf ac t u r e r •. "
..
.
,"'"7 ... ". ~,"
l.9 For anticipated
me tal
t empe r at ur e s above
..'./.
'"80°C in unlined
ch i ranay s it is necessary
to U5,e
2n alloy
steel.
The sceel
manufacturer's
advice·
sh ou l d be s o ugh t r c g a r d i ng service
t cmpe r at uraj
consideration
should
aLso be given
to the
.
a l Lowab Le s t r e s s a t s e rv i ce t empe r a r.ure , '-""'..""':'):"(':)';i"'.:
·~,r/:
..
':,'f;:.:.
...
J ••
~ F,
,,
I"
I ~';'':'.
.....
»..
,~:r
us
.i
.!,
'.'
attack·/;~~;~t]~~\~3·~,
se'lere
steel,
whe r e
f"
(~?:
'~;...
'.• -'''~·~··,'';''f':'''i·:·'''''-',.
>.~
.:
-.
•.•••
.'
·~,.I.~;~;""
•.••• :"': ••
'''o:-'''J.ft.-;;. _ ••.••.••~• .,~ •.•:.••.•.,!..,
,.-~~_•._.~.....~•.".."'!--.., - ...•....•
"""f~.......
:.--:.•..•.••.~.~:'" .....•...••..•... _ ...•••....•.•......
- .•.~.•...
..0 .. _ .....,..;l-l::':':
.:
.. .
.•~ ,J:.:. !.t.!~,~~·-
,
. .•....•• , ....,
..-
ES 4076
;
·,i
'~~"h
~
1978
11
"
:;r.,' ••
...'....
Effect
ive
r;!':lght
he
.
.~~:.!;~;
. '. '.'?~
;i~r
...•.•...
',<
"
.'.:.t-t
;':
Ih,:% a
'1
Self-supporting
chimney
- •..•..'....
• ,"
.;
. !.:\<:'
.. .!; .•,,ç',.
-c .
••••••
.:-::'
-1'
~t·
:
..
.;~;.
'~'
:~..'.:'
(J
• ~"" t,
C ross - sect ia n
considered
",{:
.,
". 0'/77/// /
..•;
,,"
~
'~i:'
,,'...\0
• - ", .
For stresses
he= /;
. ~:.'
·~/r'···
C,.
"
Supported
chimney, fixed
base
.'
For.stressesin.AB
B~
he== 0,85
I
'.
':.'
.~- ~
~."
(J
.....
Ia
I
I,
A L-_, ç , . , ,
5
,
,)
,
.
,
"
,
:..'~
):
For stresses
h:::./;
sf.7
C 1
Supported
ch imney, pinned
base
in BC
..
,
1,'
e
,;.\
~
!' ..':
For
A~Llt
st r e s s e s in AB
he= (J
..
'.
.: ':'
.~'
......
.."'J.,.
"
\
;:
.):;
C"~:
.'."
.
o'.:
'-.:
Figure
I.Effectivc".
helgilt
of
ch irn ne y s he il
'.
.<,-
.~.
./
"
i···./:·
"'r
,,'
;.
..
'
••• -~,
"
"
.
•
.<
'
..... ;.
.""
.
~.'~
'\.'
";:i::::';~
~
l"
v
. ""~:;.~'.o"'"
"::""~,:.",~~.".,~II.,,,.,,,,,,,.:;";""'"
,..•.~.".,,....;<..•.;,._ .••. ~
..
'"-i._·_: '_._._..
~I·•.•.••
:....
•.•
-'·_~
.._·J..
",. _,...;."..••""•..••_._ •••.~",.. ••.•,•..
.•.,' ..-:~~
~'~'~~;".'"
~';':;""-'";"':''''''~~~~~'';'':'''''''---~'
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1
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STA.'\DARDS
PUBLICAI1WS
BS
4
B5.
31)5
-,.
, :-.:'
-"" J
>'
~:.
y.;'
;t~
. BS
449
BS
462
BS
463
,,~ :'64
BS 325
;,S 11.:'9
~,)
~
:;~
"
BS 1470
.;;
~
}";'
'r~;
BS
s~
..'.
1485
TIS 2569
;.
F
::':;
"'(1;'
;'~
~'.
BS
2600
.
ES 4190
~.
,.
i
oS 4207
BS 4211
BS 4360
BS 4395
~~
~';
?
',
3ectio~s
~~r~ r~??~s ~cr shi~s
(ite2~
in~ ~~:~~=a:
r
St~:'::1~5;:;
an
a
r
1
5
uc
=
í
n
d
a
-a
nd
a
rc
l
uc
s
n
s
ng
um
=
nd
.
. '.'~""'1 .\:.~'''' '1
. The us~ o f hígh strength.
f:-i~tio:t
bolts
i.n s t ruccur
a'l s t ee .wo r z , ~êt.r:.c·;~.:.;}··,-,.· !
s e r ie s
.
Pare 1 Ce n e r a L grade
', I..:-:.<Ç"$~~~;;. I
Hc c+r o Ll e d s t r uc t u r a l s t e e l sei:tioris'·:f'~::~~~~\· i
Approval t e s t i ng of we l.d ng procedur.
Pare 1 F~sion. we Id í.ng of steel .•
I
Approval t e s t i ng of ve l de r s WOrklng.;}~,'!.§~"l.~7V
II
approved '.Ie Ld i ng procedure s
. ·.;';:·.{;:'f\f':( ".
P art 1 F·us i on we ld' i ng o fI'" stee
' ,",.,1·,,,,..·
,;:r<"~~.f&~~'"
•
•
,.
~ '''J'J,)':..'..
Metal-are
Ld
of
and car~o.~",:S~;'··
mang ane s e steels
'
"", . ·~v.:'~f1''I~~·}~'1
t
F~rrule
s e c u r e d eye t e rmi na t i.on s fo.r~:.;~!f.Jji!:
v i r~ e ropes
'
. ',,~~.;f.';""~.
., "'''':'·~iJ.-,1rl;,!:~"~ '1
Protective
c o a t i ng o i i r on and steel'.1J''T:f'~r~:; ,
.~~,sy~~~
:
s c ruc t ur e s ~6aLnst corrOSl.on.
"\,t-~;n:~?J~;i':::
j
Code of b as i c- da t a for the des gn of}t'c::i,·.r:"'.
bui l d i ng s
.
. -.:~:~~-;!f.:,::.
-Chapter V. Loading
·j~·
Part 1 De a d and imposed l o ad s
:. ':.,;;:.';':,~;>
P a r t 2 to; i n d 10 ad s
.
The s t r uc t u r a L use of coric r e t e
... ,~~t"S-:.:,;,:ti:
Part 1 r.,.•• s g n , materials
an d
. .,..
. workmanshlp
.
Structural
r e commend e t o ns for,""
Lo adbe ar ing wa Ll s
".,,\~I.~~~?~;n:~~~:,~
.•
"
".VI'.~':'~:r-~<d.1'::;
St ruc t ur a I use of rel.nforced.
con.cret:.e:,~;'/:-;<~y"
in buildings
',~&,~~;}r
The p ro t e c t on of s t ru c t ur e s againstSlit;~~.?fzf·
i~ips~;;}r\
5S 4604'
p c rp o s e 3
The use oi structural
seeel ir ~uil~:ng
Bull do;; g r i p s
Sockecs
for ~ire ~opes
Thicbles
for wire rcpe5
~ild s:e~l
shackles
Steel ~lat~) sheet 2~~ ~::rLp
t 2
:j t
i ti
steel Fl3t~, s~eet
and strip
l-irough:
l
i ura
.i
i i
alloys
for general
engineerir.3
purposes
place,
she~t and scr:?
Galvanized
~ire cecti~g
Sprayed =~tal coaeings
Pare 1 Pr o t e c t i cn o f i r cn a ad s t e e l 'by
al~ini~
and zinc ag~í.r.st ac~ospheric
corrosion
Part 2 Proteccion
of iron and ~teel
against
corrosion
sne oxidation
at
elevaeed
eemperaeures
Methads for the radiogiaphic
examination
of fusion ~elded bute joints
in steel
t
up to
including
50
thick
..
Access hooks ror chi~nays and other high
struccures
in sceel
"
ISO macric b13ckhe~agan
bolts,
screws
~nd nuts
~onolichic
linings
ror seeel chimneys
and flues
St.e e L Ladé e r s for p e rmane n t ac ce s s
~eldable
structural
s~~els
li i gh s c re n g ch f r ic t icn grip b o l t s arid
associated
n~ts and ~a5hers ior
structural
2ngineerir.g
Part 1 General grade
Pa
BS 3678
sceel
sc~el
c~:.al
~X?a~~i~
.. ,.'
REFERRED TO
Struct~ral
Galva~~ze~
Pa
~<
i
',
,;A:~~~)~l;;
tIS 4848
~870
ss
;:,~;:f~~:t~i
I
BS 4871
35 51J5
;iS
we
Lng
c
ar
•
3
·_~:i~:;';:..
·::~:i~~~-t.~~~
C'
110
í
CP
111
CP
1.14
CP
326
í
í
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t
n ng
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í
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t
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.Foundations
CP 2004
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