10
Transportation and Erection of
Pressure Vessels
Procedure 10-7: Design of Flange Lugs .............. 695
Procedure 10-1: Transportation of Pressure
Vessels ............................................................. 632
Procedure 10-2: Erection of Pressure Vessels ...... 660
Procedure 10-3: Lifting Attachments and
Terminology ..................................................... 666
Procedure 10-4: Lifting Loads and Forces .......... 675
Procedure 10-5: Design of Tail Beams, Lugs,
and Base Ring Details ....................................... 681
Procedure 10-6: Design of Top Head and
Cone Lifting Lugs............................................. 691
Procedure 10-8: Design of Trunnions ................. 706
Procedure 10-9: Local Loads in Shell Due
to Erection Forces............................................. 710
Procedure 10-10: Miscellaneous ......................... 713
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Pressure Vessel Design Manual
Procedure 10-1: Transportation of Pressure Vessels
The transportation of a pressure vessel by ship, barge,
road, or rail will subject the vessel to one-time-only
stresses that can bend or permanently deform the vessel if
it is not adequately supported or tied down in the right
locations. The shipping forces must be accounted for to
ensure that the vessel arrives at its destination without
damage.
It is very frustrating for all the parties involved to have
a load damaged in transit and to have to return it to the
factory for repairs. The cost and schedule impacts can be
devastating if a vessel is damaged in transit. Certain
minimal precautions can avoid the costly mistakes that
often lead to problems. Even when all precautions are
made, however, there is still the potential for damage due
to unforseen circumstances involved in the shipping and
handling process.
Care should be taken to ensure that the size and location
of the shipping saddles, tie-downs, or lashing are adequate
to hold the vessel but not deform the vessel. Long, thinwalled vessels, such as trayed columns, are especially
vulnerable to these shipping forces. The important thing to
remember is that someone must take the responsibility.
The barge and rail people have their own concerns with
regard to loading and lashing. These may or may not
coincide with the concerns of the vessel designer.
The shipping forces for ships, barges, trucks, and rail
are contained in this procedure. Each method of transportation has its own unique load schemes and resulting
forces. Barge shipping forces will differ from rail due to
the rocking motion of the seas. Rail shipments, however,
go around corners at high speed. In addition, rail forces
must allow for the “humping” of rail cars when they are
joined with the rest of the train. Ocean shipments have to
resist storms and waves without breaking free of their
lashings.
Whereas horizontal vessels on saddles are designed for
some degree of loading in that position, vertical vessels
are not. The forces and moments that are used for the
design of a vertical vessel assume the vessel is in its
operating position. Vertical vessels should generally be
designed to be put on two saddles, in a horizontal position,
and transported by various means. That is the purpose of
this procedure. Too often the details of transportation and
erection are left in the hands of people who, though well
versed in their particular field, are not pressure vessel
specialists.
Often vessels are transported by multiple means. Thus
there will be handling operations between each successive
mode of transportation. Often a vessel must be moved by
road to the harbor and then transferred to a barge or ship.
Once it reaches its destination, it must be reloaded onto
road or rail transport to the job site. There it will be offloaded and either stored or immediately erected. A final
transport may be necessary to move the vessel to the
location where it will be finally erected. At each handling
and transport phase there are different sets of forces
exerted on the vessel that must be accounted for.
Shipping Saddles
The primary concern of the vessel designer is the
location and construction of the shipping saddles to take
these forces without overstressing or damaging the vessel.
If saddles are to be relocated by the transporter, it is
important that the new locations be reviewed. Generally
only two shipping saddles should be used. However, this
may not always be possible. Remember that the reason for
using two saddles is that more than two saddles creates
a statically indeterminate structure. You are never assured
that any given saddle is going to take more than its
apportioned load.
Here are some circumstances that would allow for more
than two saddles to be used or for a special location of two
saddles:
•
•
•
•
Transporter objects due to load on tires.
Transporter objects due to load on barge or ship.
Very thin, long vessel.
Heavy-walled vessels for spreading load on ship or
transporters.
Shipping saddles can be constructed of wood or steel or
combinations. The saddles should be attached to the vessel
with straps or bolts so that the vessel can be moved
without having to reattach the saddle. Horizontal vessels
may be moved on their permanent saddles but should be
checked for the loadings due to shipping forces and
clearances for boots and nozzles. Shipping saddles should
have a minimum contact angle of 120 , just like permanent saddles. Provisions for jacking can be incorporated
into the design of the saddles to allow loading and
handling operations without a crane(s).
Transportation and Erection of Pressure Vessels
Shipping saddles should be designed with the vessel
and not left up to the transport company. In general,
transportation and erection contractors do not have
the capability to design shipping saddles or to check
the corresponding vessel stresses for the various load
cases.
Whenever possible, shipping saddles should be located
adjacent to some major stiffening element. Some common
stiffening elements include stiffening rings, heads (both
internal and external), or cones. If necessary, temporary
internal spiders can be used and removed after shipment is
complete.
Key factors for shipping saddles to consider:
•
•
•
•
•
•
•
Included angle.
Saddle width.
Type of construction.
Lashing lugs.
Jacking pockets.
Method of attachment to the vessel.
Overall shipping height allowabledcheck with
shipper.
Recommended contact angle and saddle width:
Vessel Diameter
Contact Angle
Minimum Saddle
Width
D < 13 ft-0 in.
13 ft-0 in. < D < 24 ft-0 in.
D > 24 ft-0 in.
120
140
160
11 in.
17 in.
23 in.
Vessel Stresses
The stresses in the vessel shell should be determined by
standard Zick’s analysis. The location of shipping saddles
should be determined such that the bending at the midspan
and saddles is not excessive. Also, the stresses due to
bending at the horn of the saddle is critical. If this stress is
exceeded, the saddle angle and width of saddle should be
increased. Also, move the saddle closer to the head or
a major stiffening element.
Lashing
Vessels are lashed to the deck of ships and barges.
In like manner they must be temporarily fixed to railcars, trailers, and transporters. Lashing should be
restricted to the area of the saddle locations. Vessels
633
are held in place with longitudinal and transverse
lashings. Lashings should never be attached to small
nozzles or ladder or platform clips. In some cases,
lashing may be attached to lifting lugs and base rings.
Lashings should not exceed 45 from the horizontal
plane.
Other Key Factors to Consider
• Shipping clearances.
• Shipping orientationdpay close attention to lift lugs
and nozzles.
• Shipping route.
• Lifting orientation.
• Type of transport.
• Watertight shipment for all water transportation.
• Escorts and permits.
• Abnormal loadsdsize and weight restrictions.
• Vessels shipped with a nitrogen purge.
• Shipping/handling plan.
Organizations That Have a Part in the Transportation and
Handling of Pressure Vessels
•
•
•
•
•
•
•
•
•
Vessel fabricator.
Transport company.
Engineering contractor.
Railway authorities.
Port authorities.
Erection/construction company.
Trailer/transporter manufacturer.
Ship or barge captain.
Crane company/operator.
Special Considerations for Rail Shipments
1. Any shipment may be subject to advance railroad
approval.
2. Any shipment over 10 ft-6 in. wide must have
railroad approval.
3. A shipping arrangement drawing is required for the
following:
a. All multiple carloads (pivot bolster required).
b. All single carloads over 10 ft-6 in. wide.
c. All single carloads over 15 ft-0 in. ATR (above
top of rail).
d. All single carloads that overhang the end(s) of
the car and are over 8 ft-0 in. ATR.
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Pressure Vessel Design Manual
4. Clearances must be checked for the following:
a. Vessels greater than 9 feet in width.
b. Vessels greater than 40 feet overall length.
c. Vessels greater than 50 tons.
5. The railroad will need the following specific data
as a minimum:
a. Weight.
b. Overall length.
c. Method of loading.
d. Loadpoint locations.
e. Overhang lengths.
f. Width.
g. Height.
h. Routing/route surveys.
i. Center of gravity.
6. A swivel (pivot) bolster is required whenever the
following conditions exist:
a. Two or more cars are required.
b. The capacity for a single car is exceeded.
c. The overhang of a single car exceeds 15 feet.
7. Rated capacities of railcars are based on a uniformly
distributed load over the entire length of the car.
The capacity of a car for a concentrated load will
only be a percentage of the rated capacity.
8. Rules for loads, loading, and capacities vary by
carrier. Other variables include the types of cars the
carrier runs, the availability, and the ultimate
destination. Verify all information with the specific
carrier before proceeding with the design of shipping saddles or locations.
9. For vessels that require pivot bolsters, the shipping
saddles shall be adequately braced by diagonal
tension/compression rods between the vessel and
the saddle. The rods and clips attached to the vessel
shell should be designed by the vessel fabricator to
suit the specific requirements of the carrier.
10. If requested, rail bolsters can be returned to the
manufacturer.
11. Loading arrangement and tie-downs will have to
pass inspection by a representative of the railways
and sometimes by an insurance underwriter prior to
shipment.
12. Accelerometers can be installed on the vessel to
monitor shipping forces during transit.
13. A rail expediter who accompanies the load should
be considered for critical shipments.
14. The railroad will allow a fixed time for the cars to
be offloaded, cleaned, and returned. Demurrage
charges for late return can be substantial.
Outline of Methods of Vessel Shipping and Transportation
1. Road.
a. Truck/tractor and trailer.
b. Transportersdsingle or multiple, self-propelled
or towed.
c. Specialdbulldozer.
d. Frame adapters.
e. Beams to span trailers or transporters.
f. Rollers.
g. Special.
2. Rail.
a. Single car.
b. Multiple cars.
c. Special cars.
d. Types of cars.
• Flatcar.
• Fishbelly flatcar.
• Well car.
• Heavy-duty car.
• Gondola car.
3. Barge.
a. River barge.
b. Ocean-going barge.
c. Lakes and canals.
4. Ships.
a. Roll-on, roll-off type.
b. Loading and off-loading capabilities.
c. In-hull or on-deck.
d. Floating cranes.
5. Other.
a. Plane.
b. Helicopter.
c. Bulldozer.
Transportation and Erection of Pressure Vessels
635
Table 10-1
Overland shipping limits in the US
State
Alabama
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Length, ft
Width, ft
Height, ft
Gross Weight, lb
150
120
100
120
130
120
120
150
100
110
145
110
120
126
110
125
125
100
115
150
95
100
100
110
120
105
120
120
120
120
100
120
100
100
105
120
90
125
120
120
125
125
100
150
150
150
150
110
16
14
14
14
17
15
15
16
14
16
14’6"
16
18
16’6"
16
18
16
15’11
14
16
14’6"
14
14
18
14
17
15
18
14
14
14
14’6"
14
16
14
16
14
16
14’6"
16
20
15
15
14
14
16
16
18
16
16
14
16
16
16
15
16
14
15’6"
15
15
16
16
15
16
16
15’11
14
15
14
14
14
17
15’6"
16
16
16
16
14
14
15’6"
14’10"
16
16
15’6"
13’6"
14
15’6"
15
18’11"
16’6"
14
15
16
15
16
17
180,000
250,000
120,000
220,000
228,000
250,000
250,000
250,000
120,000
200,000
250,000
250,000
250,000
250,000
250,000
250,000
250,000
220,000
240,000
230,000
250,000
120,000
120,000
240,000
212,000
240,000
250,000
220,000
250,000
160,000
120,000
150,000
120,000
212,000
220,000
201,000
120,000
250,000
150,000
250,000
252,000
250,000
150,000
150,000
200,000
212,000
250,000
252,000
Note: This information in this Table is for general, reference information only and should not be relied upon for any given application. These values
change regularly and local, state and national regulations should be checked for any given haul application.
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Transportation and Erection of Pressure Vessels
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Transportation and Erection of Pressure Vessels
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Transportation and Erection of Pressure Vessels
Table 10-2
Barge shipping forces
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Pressure Vessel Design Manual
Pitch
Roll
Case 2a: q2 [ 30 max
Cases 3a and 3b
Case 2b
Forces in Vessel Due to Pitch
General:
2 W 2p
Rqp
F ¼ ma ¼
g
T
180
Forces in Vessel Due to Roll
e
WRq
F ¼ 0:0214 2
T
a
f1 ¼ tan1
R1
f2 ¼ tan1
R2 ¼
e
sin f2
0:0214WR1 q1
Fp ¼
T21
FR ¼
0:0214WR2 q2
T22
Case 3a: Fy ¼ Fp sin f1
Fz ¼ Fp cos f1
Case 3b: Fy ¼ Fp sin f1
Fz ¼ Fp cos f1
d
Case 2a: Fy ¼ FR sin f2
Fx ¼ FR cos f2
Case 2b: Fy ¼ FR sin f2
Fx ¼ FR cos f2
Transportation and Erection of Pressure Vessels
The job of the designer is to translate the loads resulting
from the movement of the ship into loads applied to the
pressure vessel that is stored either at or below decks. The
ship itself will rotate about its own center of buoyancy
(CB) depending on the direction of the sea and the ship’s
orientation to that direction of sea. The vessel strapped to
its deck is in turn affected by its location in relation to the
CB of the ship. For example, if the CG of the vessel is
located near the CB of the ship, the forces are minimized.
The farther apart the two are in relation to each other, the
more pronounced the effect on the vessel.
The ship’s movement translates into loads on the three
principal axes of the vessel. Saddles and lashings must be
strong enough to resist these external forces without
exceeding some allowable stress point in the vessel. The
point of application of the load is at the CG of the vessel.
These loads affect the vessel in the same manner as
643
seismic forces do. In fact, the best way to think of these
loads is as vertical and horizontal seismic forces. Vertical
seismic forces either add or subtract to the weight of the
vessel. Horizontal seismic forces are either transverse or
longitudinal.
The X, Y, and Z axes translate into and are equivalent
to the following loadings in the vessel:
X axis: horizontal transverse.
Y axis: corresponds to vertical loads by either adding or
subtracting from the weight of the vessel.
Z axis: longitudinal axis of the vessel. All Z axis loads
are longitudinal loadings.
Load Combinations for Sea Forces
1. dead load þ sway þ heave þ wind
2. dead load þ surge þ heave þ wind
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Pressure Vessel Design Manual
Transportation and Erection of Pressure Vessels
Axle Loads
eccentricity of the load can overload the outer set of
wheels to the point of rollover. The two cases are;
The number of axles that must be placed under a load is
determined by analyzing the weight restrictions and
allowable bearing load from local, state or national regulations. The transportation contractor is responsible for
determining the axle loads based on the equipment used
and the weight and distribution of the loads. The authorities that permit the load will require an analysis of the axle
loads to ensure that the roadbed is not overloaded. Axle
loads include the weight of the vessel, transport saddles,
beams, hauler (tractor), dollies, etc.
There are three different methods used to distribute the
loads to the axles;
1. Flatbed: This method uses conventional tractortrailer assembly with various numbers of axles and
wheels under the trailer bed to distribute the weight
to the road surface.
2. Bolstered: This method is used for abnormally long
loads in which the sets of axles are attached directly
to the load via the transport saddle. Both sets of
axles will have steering capabilities.
3. Bolstered loads using equalizing transporting
beams: This method is much the same as the
bolstered, long vessel load. In this case the load is
too heavy for a flatbed, yet too short for bolstered
axles. The solution is to utilize beams between
bolsters to suspend the load.
Transporter Stability
There are two types of stability checks that should be
performed on each load. The first has to do with the
tipping point of the load relative to the roadway as the load
shifts due to the camber of the road. The second has to do
with the turning radius of bolstered loads. As the load goes
around curves, the C.G. shifts from being in line with the
dollies, to an eccentric condition. In tight curves the
1. Rollover stability due to road camber
2. Turning stability due to turning radius
Case 1:
Due to the camber in roads, the load will be subject to
various angles, q, that will change the location of the center
of gravity of the load. On a flat surface, the center of gravity
is in line with the centerline of the trailer. As the road
camber increases, the C.G. is steadily moved toward the
outer set of wheels. At some point the wheels are overloaded on one side and the entire assembly reaches a tipping
point. Beyond this, the trailer turns over and the load is lost.
This condition has resulted in numerous rollovers.
θ
Figure 10.1. Rollover stability.
Case 2:
For bolstered loads, the vessel must swivel on the deck
of the trailer in order to accommodate curves in the road
and corners. As the curve or corner is negotiated, the
actual CG gets further away from the projected load point.
This is true whether you have a single pivoting bolster or
two, however the situation is more pronounced with the
double pivoting case. There have been a number of rollovers as a result of the eccentricity, ie, shifting the load to
the outer row of wheels until the load becomes unstable.
PROJECTED
LOAD POINT
DOLLIE
645
e
CG OF LOAD
CENTERLINE
SUSPENDED LOAD
Figure 10.2. Turning stability.
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Transportation and Erection of Pressure Vessels
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Pressure Vessel Design Manual
Summary of Loads/Forces on Vessels During Transportation
Table 10-3
Transportation load coefficients, K
Forces
Fx
Fy
Fz
Road
Rail
Barge
Ocean
0.5
1.5
1.0
1.0
2.0
1.5
0.95
1.3
1.5
1.0
1.5
1.5
Table 10-4
Load per saddle due to transport forces
Due to . . .
Load per Saddle
Fx
Q1 ¼
Ws L2 Fx B
þ
L1
2A
Q2 ¼
Ws L3 Fx B
þ
L1
2A
Q1 ¼
ðWs þ Fy ÞL2
L1
Q2 ¼
ðWs þ Fy ÞL3
L1
Q1 ¼
Ws L2 Fz B
þ
L1
L1
Q2 ¼
Ws L3 Fz B
þ
L1
L1
Fy
Fz
Diagram
Transportation and Erection of Pressure Vessels
Load Diagrams for Moments and Forces
Case 1
Case 2
Note: W ¼ weight of vessel plus any impact factors.
W
OAL ¼ L1 þ L2 þ L3 w ¼
OAL
i
h
w ðL1 þ L2 Þ2 L23
Q1 ¼
2L1
Q 2 ¼ W Q1
wL22
M1 ¼
2
Q1
L2
M2 ¼ Q1
2w
M3 ¼
Mx ¼
wL23
2
wðL2 XÞ
2
w1 ¼
W1
L2
w2 ¼
W2
L3
Q1 ¼
WL6
L1
Q2 ¼ W Q 1
2
M1 ¼
w1 L24
2
Mx1 ¼
wðL2 þ X1 Þ2
Q 1 X1
2
M2 ¼
M1 þ M3 w1 L21
2
8
Mx2 ¼
wðL3 X2 Þ2
2
M3 ¼
w2 L23
2
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Pressure Vessel Design Manual
Case 3
WL1
WL22
Q1 ¼
2ðL1 þ L2 Þ 2L1 ðL1 þ L2 Þ
Q2 ¼
WL22
WL1
WL2
þ
þ
2ðL1 þ L2 Þ L1 þ L2 2L1 ðL1 þ L2 Þ
M1 ¼
Q21 ðL1 þ L2 Þ
2W
WL21
M2 ¼ Q1 L1 2ðL1 þ L2 Þ
WX2
Mx ¼ Q1 X 2ðL1 þ L2 Þ
Case 4
w1 ¼
W1
L2
w2 ¼
W2
L3
Q1 ¼
w1 L2 ð2L1 L2 Þ þ w2 L23
2L1
Q2 ¼
w2 L3 ð2L1 L3 Þ þ w1 L22
2L1
Moment at any point X from Q1:
Mx ¼ Q1 X w1 X2
2
Moment at any point Y from Q2:
w2 ðL1 YÞ2
My ¼ Q2 ðL1 YÞ 2
Transportation and Erection of Pressure Vessels
Transportation-Vertical Vessel on Two Saddles, Uniform
Load Case, With Incorporation of Shipping Factors
Notation
F2 ¼ Additional load on Q2, Lbs
FZ ¼ Longitudinal loading due to shipping forces,
Lbs
FY ¼ Vertical Loading due to shipping forces, Lbs
KZ ¼ Longitudinal impact factor
KY ¼ Vertical impact factor
Q1,Q2 ¼ Saddle loads without impact factors, Lbs
Q10 ,Q20 ¼ Saddle loads with impact factors, Lbs
W ¼ Shipping weight of vessel without impact
factors, Lbs
WT ¼ Shipping weight with impact factors, Lbs
w1 ¼ Uniform load, without FY, Lbs/Ft
w2 ¼ Uniform load including FY, Lbs/Ft
F2 ¼ ðFZ BÞ=L1
• Saddle loads, Q1, Q2, Q10 , Q20
h
i.
Q1 ¼ w1 ðL1 þ L2 Þ2 L23 2 L1
Q1 0 ¼ Q 1 F 2
Q2 ¼ W Q1
Q2 0 ¼ Q2 þ F2
Case 2: Adding Loads for Fy
• Longitudinal load, FY
FY ¼ KY W
• Vertical load, FY
WT ¼ W þ FY
LT
• Uniform load, w2
L3
L1
L2
w1 or w2
Fz
B
Q1
W
WT
Q2
M2
w2 ¼ WT =LT
• Saddle loads, Q10 & Q20
h
i
Q1 0 ¼ w2 ðL1 þ L2 Þ2 L23 =2L1
Q2 0 ¼ WT Q1 0
M1
M3
Figure 10.3. Data for uniform load case
NOTE: Assume that FZ & FY do not occur at the same
time
Select worst case and calculate moments;
M1 ¼ wn L22 =2
M2 ¼ Q1 0 Q1 0 = 2 wn L2
M3 ¼ wn L23 =2
Case 1: Adding Load for Fz
Sample Problem
• Longitudinal load, FZ
FZ ¼ KZ W
• Uniform load, w1
w1 ¼ W=LT
• Additional load on saddle, F2
Given;
B ¼ 15.75 ft
L1 ¼ 124 ft
L2 ¼ 24 ft
L3 ¼ 21 ft
LT ¼ 169 ft
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Pressure Vessel Design Manual
Q1 0 ¼ Q1 F2 ¼ 379 56:5 ¼ 322:5 kips
Q2 ¼ W Q1 ¼ 741 379 ¼ 362 kips
Q2 0 ¼ Q2 þ F2 ¼ 362 þ 56:5 ¼ 418:5 kips
W ¼ 741 kips
KY ¼ .5
KZ ¼ .6
Calculation
FZ ¼ KZ W ¼ :6 ð741Þ ¼ 444:6 kips
FY ¼ KY W ¼ :5 ð741Þ ¼ 370:5 kips
WT ¼ W þ FY
¼ 741 þ 370:5 ¼ 1; 111:5 kips
w1 ¼ W=LT ¼ 741=169 ¼ 4:38 kips=ft
w2 ¼ WT =LT ¼ 1111:5=169 ¼ 6:58 kips=ft
F2 ¼ ðFZ BÞ=L1 ¼ ½444:6 ð15:75Þ=124
¼ 56:47 kips
Case 1: Adding Load for FZ
• Saddle loads, Q1, Q2, Q10 , Q20
h
i.
Q1 ¼ w1 ðL1 þ L2 Þ2 L23 2 L1
i. h
¼ 4:38 ð124 þ 24Þ2 212 2 124
¼ 379 kips
Case 2: Adding Load for FY
• Saddle loads, Q10 & Q20
h
i.
Q1 0 ¼ w2 ðL1 þ L2 Þ2 L23 2 L1
i. h
¼ 6:58 ð124 þ 24Þ2 212 2 124
¼ 569 kips
Q1 0 ¼ WT Q1 0 ¼ 1111:5 569
¼ 542:5 kips
Worst case is Case 2;
Determine moments.
2
M1 ¼ w2 L22 2 ¼ 6:58 242
¼ 1; 895 ft kips
M2 ¼ Q 1 0 Q 1 0 = 2 w 2 L 2
¼ 569 ð569=ð2$6:58Þ 24Þ ¼ 10; 946 ft kips
M3 ¼ w2 L23 2 ¼ 6:58 212
2 ¼ 1; 450 ft kips
Use these moments and loads to determine stresses in
shell.
Transportation and Erection of Pressure Vessels
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Transportation and Erection of Pressure Vessels
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Tension Bands on Saddles
Notation
Ar
As
Ab
Aw
B
d
f
Ft
Fx, Fy, Fz
K
N
Pe
R
T
T1,2,3
Tb
Ws
b
sa
sb
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
area required, in.2
area of bolt, in.2
area of band required, in.2
allowable load on weld, lb/in.
saddle height, in.
bolt diameter, in.
load on weld, kips/in.
allowable stress, tension, psi
shipping, external forces, lb
maximum band spacing, in.
number of bands on one saddle
equivalent external pressure, psi
outside vessel radius, in.
tension load in band, lb
load cases in bolt and band, lb
tension load in bolt, lb
weight of one saddle, lb
angle of tension bands, degrees
stress in bolt, psi
stress in band, psi
Transportation and Erection of Pressure Vessels
• Find tension in band, T1, due to shipping forces on
saddle, Fx and Fy.
Fx B Fy Ws
þ
T1 ¼ cos b
4N
4RN
• Area required for bolt.
Ar ¼
T1
Ft
• Maximum tension load in bolts, T2.
T2 ¼ sa As
• Load due to saddle weight, T3.
Ws
T3 ¼
2N
Note: Include impact factor in weight of saddle.
• Find maximum load, T.
• Find bolt diameter, d.
rffiffiffiffiffiffiffiffi
4Ar
d ¼
p
T ¼ greater of T1 ; T2 ; or T3 :
• Load on weld, f.
f ¼
Select nominal bolt diameter:
As ¼
45; 000
sa ¼ pffiffiffi
d
/ 16 in.
¼ in.
5
/ 16 in.
⅜ in.
7
/ 16 in.
* Kips/in. of weld.
Use w ¼
• Maximum band spacing, K.
pffiffiffiffiffi
4 Rt
K ¼
1:285
• Find area required for tension band, Ar.
Table 10-5
Allowable load, weld
3
T
4[
• Determine size of weld from table based on load, f.
• Find maximum stress in bolt due to manual
wrenching, sa.
Weld Size, w
657
Ar ¼
E60XX*
E70XX*
2.39
3.18
3.98
4.77
5.56
2.78
3.71
4.64
5.57
6.50
T
Ft
Use:
• Check shell stresses due to force T, Pe.
4T
Pe ¼
< ASME factor “B”
pRK
658
Pressure Vessel Design Manual
• Horizontal distance to centroid of saddle, X
Alternate Procedure
X ¼ R sin a
• Tension load in band, T
Tension Band Notation
N
Q
R
T
b
K1
K2
X
¼
¼
¼
¼
¼
¼
¼
¼
Number of bands on one saddle
Total load on one saddle, Lbs
Outside vessel radius, in
Tension load in band, Lbs
Angle of tension bands, degrees
Transverse shipping coefficient
Vertical shipping coefficient
Horizontal distance to centroid of saddle
reaction, in
Y ¼ Vertical distance to centroid of saddle, in
T ¼ ½Q ½ðK1 Y=XÞ þ K2 =½2N cos b
Notes
1. Vertical reaction can be a result of longitudinal load.
Use largest value
2. Use K2 ¼ 0 for transverse case
3. Use K1 ¼ 0 for longitudinal case
4. Use worst case of T1 or T2 and design the balance of
components per previous method
K2 W
Example
R
K1 W
θ
B
α
β
T
Y
X
A
Figure 10-4. Dimensions of shipping saddle for alternate
case.
Calculation
• Vertical distance to centroid of saddle, Y
Y ¼ R sin q=q
• Find angle, a
a ¼ cos1 Y=R
K1
K2
Q
R
q
b
N
¼
¼
¼
¼
¼
¼
¼
.25
.5
500 kips
92.5 in
75 ¼ 1.308 rad
7.5
2
Y ¼ R sin q/q
Y ¼ 92.5 sin 75 / 1.308 ¼ 68.3 in
a ¼ cos-1 (Y / R)
a ¼ cos-1 (68.3 / 92.5) ¼ 42.4o
X ¼ R sin a
X ¼ 92.5 (sin 42.4) ¼ 62.4 in
Transverse (K2 ¼ 0)
T1 ¼ [Q [(K1 Y / X) þ K2]] / [2N cos b]
T1 ¼ [500 [(0.25$68.3/62.4) þ 0]] /[2$2 cos 7.5] ¼
34.35 kips
Longitudinal (K1 ¼ 0)
T2 ¼ [Q [(K1 Y / X) þ K2]] / [2N cos b]
T2 ¼ [500 [0 þ 0.5]] / [2$2 cos 7.5] ¼ 63.04 kips
Transportation and Erection of Pressure Vessels
659
660
Pressure Vessel Design Manual
Procedure 10-2: Erection of Pressure Vessels
The designer of pressure vessels and similar equipment
will ultimately become involved in the movement, transportation, and erection of that equipment. The degree of
that involvement will vary due to the separation of duties
and responsibilities of the parties concerned. It is prudent,
however, for the designer to plan for the eventuality of
these events and to integrate these activities into the
original design. If this planning is done properly, there
is seldom a problem when the equipment gets to its
final destination. Conversely, there have been numerous
problems encountered when proper planning has not
been done.
There is also an economic benefit in including the
lifting attachments in the base vessel bid and design.
These lifting attachments are relatively inexpensive in
comparison to the overall cost of the vessel and minuscule
compared to the cost of the erection of the equipment. The
erection alone for a major vessel can run into millions of
dollars. If these attachments are added after the purchase
order is awarded, they can become expensive extras.
There are also the consequences to life, property, and
schedules if this activity is not carried out to a successful
conclusion. Compared to the fabricated cost of the lifting
attachments, the consequences to life, property, and
schedule are too important to leave the design of these
components and their effect on the vessel to those not fully
versed in the design and analysis of pressure vessels.
In addition, it is important that the designer of the lifting
attachments be in contact with the construction organization that will be executing the lift. This ensures that all
lifting attachments meet the requirements imposed by the
lifting equipment. There are so many different methods
and techniques for the erection of vessels and the related
costs of each that a coordinated effort between the
designer and erector is mandatory. To avoid surprises,
neither the designer nor the erector can afford to work in
a vacuum. To this end, it is not advisable for the vessel
fabricator to be responsible for the design if the fabricator
is not the chief coordinator of the transport and erection of
the vessel.
Vessels and related equipment can be erected in
a variety of ways. Vessels are erected by means of single
cranes, multiple cranes, gin poles, jacking towers, and
other means. The designer of the lifting attachments
should not attempt to dictate the erection method by the
types of attachments that are designed for the vessel. The
selection of one type of attachment versus another could
very well do just that.
Not every vessel needs to be designed for erection or
have lifting attachments. Obviously the larger the vessel,
the more complex the vessel, the more expensive the
vessel, the more care and concern that should be taken into
account when designing the attachments and coordinating
the lift. The following listing will provide some guidelines
for the provision of special lifting attachments and a lifting
analysis to be done. In general, provide lifting attachments
for the following cases:
• Vessels over 50,000 lb (25 tons).
• Vessels with L/D ratios greater than 5.
• Vertical vessels greater than 8 ft in diameter or 50 ft
in length.
• Vessels located in a structure or supported by
a structure.
• High-alloy or heat-treated vessels (since it would not
be advisable for the field to be doing welding on
these vessels after they arrive on site, and wire rope
slings could contaminate the vessel material).
• Flare stacks.
• Vessels with special transportation requirements.
At the initial pick point, when the vessel is still horizontal, the load is shared between the lifting lugs and the
tail beam or lug, based on their respective distances to the
vessel center of gravity. As the lift proceeds, a greater
percentage of the load is shifted to the top lugs or trunnions until the vessel is vertical and all of the load is then
on the top lugs. At this point the tail beam or shackle can
be removed.
During each degree of rotation, the load on the lugs,
trunnions, tailing device, base ring, and vessel shell are
continually varying. The loads on the welds attaching
these devices will also change. The designer should
evaluate these loadings at the various lift angles to
determine the worst coincident case.
The worst case is dependent on the type of vessel and
the type of attachments. For example, there are three
types of trunnions described in this procedure. There is
the bare trunnion (Type 3), where the wire rope slides
around the trunnion itself. While the vessel is in the
horizontal position (initial pick point), the load produces
a circumferential moment on the shell. Once the vessel
is in the upright position, the same load produces
Transportation and Erection of Pressure Vessels
a longitudinal moment in the shell. At all the intermediate angles of lift there is a combination of circumferential and longitudinal moments. The designer should
check the two worst cases at 0 and 90 and several
combinations in between.
The same trunnion could have a lifting lug welded to
the end of the trunnion (Type 1). This lug also produces
circumferential and longitudinal moments in the shell.
However, in addition this type of lug will produce
a torsional moment on the shell that is maximum at 0 and
zero at 90 of angular rotation. The rotating lug (Type 2)
eliminates any torsional moment.
There is one single lift angle that will produce the
maximum stress in the vessel shell but no lift angle that is
the worst for all vessels. The worst case is dependent on
the type of lift attachments, distances, weights, and position relative to the center of gravity.
The minimum lift location is the lowest pick point that
does not overstress the overhanging portion of the vessel.
The maximum lift location is the highest pick point that
does not overstress the vessel between the tail and pick
points. These points become significant when locating the
lift points to balance the stress at the top lug, the overhang,
and the midspan stress.
The use of side lugs can sometimes provide an
advantage by reducing the buckling stress at midspan and
the required lift height. Side lugs allow for shorter boom
lengths on a two-crane lift or gin poles. A shorter boom
length, in turn, allows a higher lift capacity for the cranes.
The lower the lug location on the shell, the shorter the lift
and the higher the allowable crane capacity. This can
translate into dollars as crane capacity is affected. The
challenge from the vessel side is the longitudinal bending
due to the overhang and increased local shell stresses. All
of these factors must be balanced to determine the lowest
overall cost of an erected vessel.
Requirement for Erection and Setting of Vertical Vessels
The following is a brief synopsis of general recommendations regarding the setting, leveling and shimming
of vertical vessels. The following should be considered as
guidelines only. There are no codes or standards that are
applied. In general, company specifications contain
contract requirements for the contractors scope of supply
or duties. The following lists help to clarify general
construction practices with regard to the setting of vertical
vessels and towers.
661
Contractor Duties
1. Prepare tops of foundations (bush hammer if
required)
2. Perform surveying as required to establish centerlines, sole plate or shim elevations at bottom of base
of equipment
3. Shimming
4. Erect equipment
5. Level/plumbing
6. Final alignment
7. Grouting
8. Bolting
Tolerances
Out of vertical tolerance for vertical vessels, unless
specified otherwise, shall be 0.1% of the vessel height,
or about ¼ inch for every 20 feet to a maximum of
¾ inches.
Soleplates (also called bearing pads, leveling
plates or embedments)
Soleplates are stainless steel plates, 0.5 inches to
0.75 inches thick, set in grout, on top of the foundation at
the exact height of the underside of the base plate. As
a rule, two soleplates should be installed per anchor bolt,
one on each side of the bolt. Depending on the tower
diameter, and the distance between the anchor bolts,
another soleplate may be installed between adjacent
anchor bolts. The dimensions of the soleplates will vary
according to the width of the vessel base ring and vessel
weight. Soleplates are supported in place by a mixture of
Portland cement and sand in proportions 1:3. The vessel
should not be erected until the soleplates have been in
place for 28 days to allow for concrete curing. Shims and
soleplates will remain in place after the grouting operation.
Shims
Shims are used to provide precise leveling of the vessel.
Shim packs may be grouted into the foundation in lieu of
sole plates but this practice is unusual. Typically, shims
are used on top of the sole plates for the leveling operation. Special shims may be required for unique applications such as a large vessel supported on a braced frame
structure with minimal contact/bearing at each support
662
Pressure Vessel Design Manual
point. The following are some guidelines for the use of
shims.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Shims. If left in place, shall be stainless steel
Shims must have rounded corners
Shims will be fixed in place
Shims shall be deburred
Shims shall be full bearing
Shims may be horseshoe type
Shims thinner than 0.001 inches are not allowed
Shims with holes are not allowed
Shims should be the full width of the base plate
Leveling/Straightness/Plumbness
After the vessel has been placed on its foundation it
must be checked to be certain it is vertical and plumb.
Leveling is normally checked by use of two theodilites,
90 degrees apart. The theodilites shall be spaced an
adequate distance from the vessel to allow visual field of
the entire height of the vessel. Adjustments can be made to
the vessel alignment by means of wedges, either powered
or not, and then shimmed. The wedges should not be left
in place after shimming.
The vessel may be heated by the sun to a higher
temperature on one side than the other. This can create
a slight “banana” effect which should be taken into
account when checking levelness. The equation for
calculating the deflection from this effect is as follows:
2 ¼ p D2 t H2 aDT 8 I
where;
2 ¼
D ¼
T ¼
H ¼
a ¼
DT ¼
Deflection, in
Diameter, ft
Thickness, in
Height, ft
Coefficient of thermal expansion, in/in/ F
Temperature difference from one side of the
column to the other, F
I ¼ Moment of inertia of vessel cross section, ft4
Bolting
After the vessel is aligned and shimmed, the nuts on the
anchor bolts must be tightened. The vessel should not be
left standing without the crane attached unless all anchor
bolts have been tightened.
The anchor bolts should not be tightened to their
maximum load until the drypacking under the base plate
is complete. At this stage, the base plate is suspended
between the soleplates until the drypack is installed.
Since the soleplates straddle the anchor bolts, there is
a chance of deforming the baseplate prior to the installation of the drypack, if the anchor bolts are over
tightened.
After drypacking, the anchor bolts should be tightened to the correct torque to produce the maximum
allowable bolt stress. The anchor bolts should not be
tightened beyond the point of maximum allowable bolt
stress.
Note that the initial anchor bolt tension does not
increase the maximum bolt tension caused by wind or
earthquake. This initial tension will only clamp the base
ring to the concrete. Both are in equal compression until
the external load is applied. The external load reduces the
compression in the concrete before additional load is
applied to the bolts. After the external load overcomes all
the compression in the concrete, the stress in the bolt will
increase to the value it would have been, had there been no
initial tension.
Grouting
Grout under base plates shall provide full uniform load
transfer between the bottom of the base plate and the top
of the foundation. Load transfer to the foundation must be
through the grout, not through the shims or soleplate.
Prior to setting of the vessel, the top of the foundation
should be bush hammered and cleaned. This ensures that
the grout will adhere to the surface of the foundation. Bush
hammering may be done strictly under the base plate or
across the entire top of the foundation.
Once the vessel is leveled, shimmed and bolted it is
ready to be grouted. Grouting shall consist of filling the
void area between the top of foundation and the underside
of base plate with cementatious grout. The grout shall be
installed in accordance with the manufacturers recommendations and any applicable contract specifications.
Depending on the type of grout to be used, grout dams
may be used.
9,874
132 mm × 15 m SLING
SWL = 120 TON (S.P)
DOUBLE (2 PCS)
SWL = 500 T × 4.0 m LENGTH
SPREADER BEAM
SWL = 400T SHACKLE (4 NOS)
18
1,026
100 mm × 20 m SLING
SWL = 90 TON (S.P)
SWL = 73.7 TON (B.H)
DOUBLE (2 PCS)
1,829
1,692
40
m
,8
24
m
m
M 36
BOO
90 mm × 15 m SLING
SWL = 60 TON (S.P)
SWL = 44.1 TON (B.H)
DOUBLE (2 PCS)
T
0
M
AS
16
,
ø4
17,000
20,000
1,000
Counter
Weight = 40ton
1,000
Counter
Weight = 275ton
SWL = 400T SHACKLE
(1 NO.)
9,000
62,000
Figure 10-5. Typical example of erection study.
9,000
13,000
Transportation and Erection of Pressure Vessels
BOOM 96
ø3
663
664
Pressure Vessel Design Manual
Steps in Design
Given the overall weight and geometry of the vessel
and the location of the center of gravity based on the
erected weight, apply the following steps to either
complete the design or analyze the design.
Step 1: Select the type of lifting attachments as an
initial starting point:
Lift end (also referred to as the “pick end”):
a. Head lug: Usually the simplest and most
economical, and produces the least stress.
b. Cone lug: Similar to a head lug but located at
a conical transition section of the vessel.
c. Side lug: Complex and expensive.
d. Top flange lug: The choice for high-pressure
vessels where the top center flange and head are
very rigid. This method is uneconomical for
average applications.
e. Side flange lug: Rarely used because it requires
a very heavy nozzle and shell reinforcement.
f. Trunnions: Simple and economical. Used on
a wide variety of vessels.
g. Other.
Tail end:
a. Tail beam.
b. Tail lug.
c. Choker (cinch); see later commentary.
Tailing a column during erection with a wire rope
choker on the skirt above the base ring is a fairly common
procedure. Most experienced erectors are qualified to
perform this procedure safely. There are several advantages to using a tailing choker:
• Saves material, design, detailing, and fabrication.
• Simplifies concerns with lug and shipping
orientations.
• May reduce overall height during transportation.
There are situations and conditions that could make the
use of a tailing choker impractical, costly, and possibly
unsafe. Provide tailing lugs or a tailing beam if:
• The column is more than about 10 feet in diameter.
The larger the diameter, the more difficult it is for the
wire rope to cinch down and form a good choke on
the column.
• The tail load is so great that it requires the use of
slings greater than about 1½ inches in diameter. The
larger the diameter of the rope, the less flexible it is
and the more likely that it could slip up unexpectedly
during erection.
Step 2: Determine the forces T and P for all angles of
erection.
Step 3: Design/check the lifting attachments for the
tailing force, T, and pick force, P.
Step 4: Design/check the base ring assembly for
stresses due to tailing force, T.
Step 5: Determine the base ring stiffening configuration, if required, and design struts.
Step 6: Check shell stresses due to bending during lift.
This would include midspan as well as any
overhang.
Step 7: Analyze local loads in vessel shell and skirt due
to loads from attachments.
Allowable Stresses
Per AISC:
Tension
Ft ¼ 0:6Fy on gross area
¼ 0:5Fu on effective net area
¼ 0:45Fy for pin-connected members
Compression
(for short members only)
Fc ¼ Use buckling value:
¼ for vessel shell: 1:33 ASME Factor }B}
Shear
Fs ¼ Net area of pin hole: 0:45Fy
¼ other than pin-connected members: 0:4Fy
¼ fillet welds in shear:
E60XX : 9600 lb=in: or 13; 600 psi
E70XX : 11; 200 lb=in: or 15; 800 psi
Bending
Fb ¼ 0.6Fy to 0.75Fy, depending on the shape of the
member
Bearing
Fp ¼ 0.9Fy
Combined
Shear and tension:
sa s
þ 1
Fa Fs
Transportation and Erection of Pressure Vessels
Tension, compression and bending:
sa sb
sT sb
þ 1 or
þ
1
Fa Fb
FT Fb
Note: Custom-designed lifting devices that support
lifted loads are generally governed by ASME B30.20
“Below the hook lifting devices.” Under this specification,
design stresses are limited to Fy/3. The use of AISC
allowables with a load factor of 1.8 or greater will
generally meet this requirement.
Notation
A
Aa
Ab
An
Ap
Ar
As
C
Do
D1
D2
D3
Dsk
Dm
E
fr
fL
fs
Fa
Fb
Fc
Fp
Fs
Ft
Fy
I
Jw
K
KL
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
Ki ¼
Kr ¼
Ks ¼
KT ¼
Ls ¼
area, in.2
area, available, in.2
area, bolt, in.2
net cross-sectional area of lug, in.2
area, pin hole, in.2
area, required, in.2
area, strut, in.2 or shear area of bolts
lug dimension, see sketch
diameter, vessel OD, in.
diameter, lift hole, in.
diameter, pin, in.
diameter, pad eye, in.
diameter, skirt, in.
mean vessel diameter, in.
modulus of elasticity, psi
tail end radial force, lb
tail end longitudinal force, lb
shear load, lb or lb/in.
allowable stress, combined loading, psi
allowable stress, bending, psi
allowable stress, compression, psi
allowable stress, bearing pressure, psi
allowable stress, shear, psi
allowable stress, tension, psi
minimum specified yield stress, psi
moment of inertia, in.4
polar moment of inertia of weld, in.4
end connection coefficient
overall load factor combining impact and safety
factors, 1.5–2.0
impact factor, 0.25–0.5
internal moment coefficient in circular ring due
to radial load
safety factor
internal tension/compression coefficient in
circular ring due to radial load
length of skirt/base stiffener/strut, in.
M
Mb
MC
ML
MT
Nb
¼
¼
¼
¼
¼
¼
N ¼
nL
P
Pe
PL
Pr
PT
Rb
r
Rc
Su
tb
tg
tL
tP
ts
T
Tb
Tt
w1
w2
w3
w4
w5
WE
WL
Z
a
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
b
s
sb
sp
sc
scr
sT
s
sT
q
qB
qH
qv
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
665
moment, in.-lb
bending moment, in.-lb
circumferential moment, in.-lb
longitudinal moment, in.-lb
torsional moment, in.-lb
number of bolts used in tail beam or flange
lug
width of flange of tail beam with a web stiffener
(N ¼ 1.0 without web stiffener)
number of head or side lugs
pick end load, lb
equivalent load, lb
longitudinal load per lug, lb
radial load, lb
transverse load per lug, lb
radius of base ring to neutral axis, in.
radius of gyration of strut, in.
radius of bolt circle of flange, in.
minimum specified tensile stress of bolts, psi
thickness of base plate, in.
thickness of gusset, in.
thickness of lug, in.
thickness of pad eye, in.
thickness of shell, in.
tail end load, lb
bolt pretension load, lbs
tangential force, lb
fillet weld size, shell to re-pad
fillet weld size, re-pad to shell
fillet weld size, pad eye to lug
fillet weld size, base plate to skirt
uniform load on vessel, lb/in.
design erection weight, lb
erection weight, lb
section modulus, in.3
angular position for moment coefficients in base
ring, clockwise from 0
angle between parallel beams, degrees
stress, combined, psi
stress, bending, psi
stress, bearing, psi
stress, compression, psi
critical buckling stress, psi
stress, tension, psi
shear stress, psi
torsional shear stress, psi
lift angle, degrees
minimum bearing contact angle, degrees
sling angle to lift line, horizontal, degrees
sling angle to lift line, vertical, degrees
666
Pressure Vessel Design Manual
Procedure 10-3: Lifting Attachments and Terminology
Transportation and Erection of Pressure Vessels
667
668
Pressure Vessel Design Manual
Transportation and Erection of Pressure Vessels
669
670
Pressure Vessel Design Manual
Transportation and Erection of Pressure Vessels
671
672
Pressure Vessel Design Manual
Tailing Trunnion
Shell Flange Lug
Utilizes reinforced openings in skirt with through pipe.
Pipe is removed after erection and the openings used as
skirt manways.
Lifting Device Utilizing Top Body Flanges
Transportation and Erection of Pressure Vessels
673
674
Pressure Vessel Design Manual
Miscellaneous Lugs, WL < 60 kips
Table 10-6
Lug dimensions
WL kips
4
6
8
10
12
14
16
18
A
D1
B
C
tL
w1
WL kips
A
D1
B
C
tL
w1
3
3.5
4
4.5
5
5.5
6.5
7
0.88
1
1.13
1.25
1.38
1.5
1.63
1.75
1.5
1.63
1.75
2
2.13
2.38
2.5
2.75
2
2
2
2
3
3
3
3
0.5
0.63
0.63
0.75
0.88
1
1
1
0.25
0.25
0.25
0.25
0.25
0.38
0.38
0.38
20
25
35
40
45
50
55
60
7
7
8
8
8
10
10
10
1.75
2.38
2.38
2.38
2.88
2.88
2.88
2.88
3
4
4
4
4
4
4
4
3
4
4
4
4
4
4
4
1
1
1.125
1.125
1.125
1.25
1.25
1.25
0.38
0.44
0.5
0.63
0.63
0.75
0.75
0.88
Figure 10-6. Dimensions and forces.
Calculations
Due to bending:
tL ¼
6PT B
A2 F b
Hertzian Stress, Bearing
vffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
u P
u
u E
ðR1 R2 Þ
t
tL
sp ¼ 0:418
< 2Fy
R1 R 2
Due to shear:
tL ¼
2. Design each lug for a 2:1 safety factor.
3. Design each lug for a minimum 10% side force.
PT
ðA D1 ÞFs
Due to tension:
Shear Load in Weld
PL
tL ¼
ðA D1 ÞFt
Notes
1. Table 10-6 is based on an allowable stress of 13.7
ksi.
Type 1: greater of following:
6PT B
sw ¼
2A2
PL
sw ¼
2A
Type 2: Use design for top head lug.
Transportation and Erection of Pressure Vessels
Procedure 10-4: Lifting Loads and Forces
675
676
Pressure Vessel Design Manual
Transportation and Erection of Pressure Vessels
• Radial loads in shell due to sling angles, qy or qH.
Loads
• Overall load factor, KL.
KL ¼ Ki þ Ks
• Design lift weight, WL.
WL ¼ KL WE
and
and
Pr ¼ PL tan qv
Vessel in vertical
f r ¼ T sin q
or
P ¼ WL T
At q ¼ 90 , vessel vertical:
T¼0
Vessel in horizontal
f L ¼ T cos q
At q ¼ 0, initial pick point, vessel horizontal:
WL L3
P ¼
L1
Pr ¼ PT tan qH
• Tailing loads, fL and fr.
• Tailing load, T.
WL cos q L2
T ¼
cos q L1 þ sin q L4
WL L2
T ¼
L1
677
P ¼ WL
• Calculate the loads for various lift angles, q.
• Longitudinal bending stress in vessel shell, sb.
sb ¼
4M
pD2m t
Maximum moment occurs at initial pick, when q ¼ 0. See
cases 1 through 4 for maximum moment, M.
Note
If the tailing point is below the CG as is the case
when a tailing frame or sled is used, the tail support
could see the entire weight of the vessel as erection
approaches 90 .
Lift angles shown are suggested only to help find the
worst case for loads T and P.
• Maximum transverse load per lug, PT.
P cos q
PT ¼
nL
• Maximum longitudinal load per lug, PL.
P sin q
PL ¼
nL
678
Pressure Vessel Design Manual
Dimensions and Moments for Various Vessel
Configurations
Case 3: Cone Lug or Trunnion
Case 1: Top Head Lug, Top Head Trunnion, or Top
Head Flange
WL1
WL2
w6 ¼
L4
L1
w6
M1 ¼
ðL1 þ L4 Þ2 ðL1 L4 Þ2
8L21
w5 ¼
M1 ¼
WL L3 L2
L1
M2 ¼
w5 L24
2
Case 4: Cone Lug or Trunnion with Intermediate
Skirt Tail
Case 2: Side Lug or Side Trunnion
w5 ¼
WL
L5
M1 ¼
w5
ðL1 þ L4 Þ2 ðL1 L4 Þ2
8L21
M2 ¼
w5 L24
2
w5 ¼
WL1
L4
M1 ¼
w6 L25
2
w6 ¼
WL2
L1 þ L5
w5 L24
2
w6 L21
M1 þ M3
M3 ¼
2
8
M2 ¼
Transportation and Erection of Pressure Vessels
Find Lifting Loads at Any Lift Angle for a Symmetrical Horizontal Drum
Dimensions and Forces
Free-Body Diagram
Curve is based on the following equation:
Example
Steam drum:
WL ¼ 600 kips
L1 ¼ 80 ft
L4 ¼ 5 ft
L1
80
¼
¼ 8
2L4
10
P
L4
¼
ðtan qÞ þ 0:5
L1
WL
Results from curve
@q¼
@q¼
@q¼
@q¼
@q¼
15
30
45
60
75
¼
¼
¼
¼
¼
51.6%
53.6%
56.3%
60.8%
73.3%
679
680
Pressure Vessel Design Manual
Sample Problem
Case 1: L3 > L2
Case 2: L3 < L2
L1 ¼
L2 ¼
L3 ¼
L4 ¼
L1
L2
L3
L4
280 þ 2.833 þ 1 ¼ 283.83 ft
283.83 – 162 ¼ 121.83 ft
161 þ 1 ¼ 162 ft
10 ft
¼
¼
¼
¼
283.83 ft
162 ft
121.83 ft
10 ft
Transportation and Erection of Pressure Vessels
Procedure 10-5: Design of Tail Beams, Lugs, and Base Ring Details
681
682
Pressure Vessel Design Manual
Transportation and Erection of Pressure Vessels
Base Ring Design Check
C1 ¼
SAY
SA
C2 ¼ WB C1
I ¼ SAY2 þ SIo C1 SAY
RB ¼ inside radius of base plate þ C2
Internal Forces and Moments in the Skirt Base
During Lifting
To determine the stresses in the base ring as a result of
the tailing load, the designer must find the coefficients Kr
and KT based on angle a as shown and the type of stiffening in the skirt/base ring configuration.
M ¼ Kr TRB
Tt ¼ KT T
683
684
Pressure Vessel Design Manual
Skirt/Tail Beam Calculations
Tail Beam
• Tailing loads, fL and fr.
f L ¼ T cos q
f r ¼ T sin q
• Maximum bending moment, Mb.
Mb ¼ xf r þ yf L
• Maximum bending stress, sb.
sb ¼
Mb
Z
Tail Beam Bolts
• Shear load, fs.
fs ¼
0:5f r
n
• Shear stress, s.
s ¼
fs
Ab
• Tension force, ft.
Note: y1 ¼ mean skirt diameter or centerline of bolt
group if a filler plate is used.
ft ¼
Mb
y1
Skirt
• Tension stress in bolts, sT.
fT
sT ¼
Nb Ab
• Compressive force in skirt, fc.
fc ¼ fL þ ft
• Skirt crippling is dependent on the base configuration and lengths l1 through l4.
N ¼ 1 in. if web stiffeners are not used
N ¼ width of top flange of tail beam if web stiffeners are
used
• Compressive stress in skirt, sc.
sc ¼
fc
tsk ln
• Check shear stress, s, in base to skirt weld.
s ¼
fr
pDsk , 0:707w4
Base Plate
• Bending moment in base plate, Mb.
Mb ¼ Kr TRB
• Find tangential force, Tt.
Tt ¼ KT T
• Total combined stress, s.
sT ¼
Mb C1 Tt
þ
I
A
sC ¼
Mb C2 Tt
I
A
tension
compression
Transportation and Erection of Pressure Vessels
Size Base Ring Stiffeners
Three Point
F1 ¼ force in strut or tailing beam, lb
F1 is (þ) for tension and (–) for compression
• Tension stress, sT.
Fn
sT ¼
As
• Critical buckling stress per AISC, scr.
sffiffiffiffiffiffiffiffi
2p2
Cc ¼
Fy
scr
F1 ¼ ðþÞ0:453T
1 KL2s =r 2C2c Fy
¼
ð5=3Þ þ ðð3KLs =rÞ=8Cc Þ ðKLs =rÞ3 =8C3c
F2 ¼ ðÞ0:329T
Parallel Beams/Struts
• Actual compressive stress, sc.
sc ¼
Fn
As
Note: Evaluate all struts as tension and compression
members regardless of sign, because when the vessel is
sitting on the ground, the loads are the reverse of the signs
shown.
Two Point
F1 ¼ ðþÞ0:25T
Four Point
F1 ¼ ðþÞ0:5T
F1 ¼ ðþÞ0:5T
F2 ¼ ðÞ0:273T
F3 ¼ ðþÞ0:273T
685
686
Pressure Vessel Design Manual
Table 10-7
Internal moment coefficients for base ring
One Point
Angle a
Kr
Two Point
KT
Kr
Three Point
KT
Kr
KT
Four Point
Kr
KT
0
0.2387
e0.2387
0.0795
e0.2387
e0.0229
0.1651
0.0093
e0.1156
5
0.1961
e0.2802
0.0587
e0.2584
e0.0148
0.1708
0.0048
e0.1188
10
0.1555
e0.3171
0.0398
e0.2736
e0.0067
0.1764
0.0012
e0.1188
15
0.1174
e0.3492
0.0229
e0.2845
e0.0055
0.1747
e0.0015
e0.1155
20
0.0819
e0.3763
0.0043
e0.2908
e0.0042
0.1729
e0.0033
e0.1089
25
0.0493
e0.3983
e0.0042
e0.2926
0.0028
0.1640
e0.0043
e0.0993
30
0.0197
e0.4151
e0.0145
e0.2900
0.0098
0.1551
e0.0045
e0.0867
35
e0.0067
e0.4266
e0.0225
e0.2831
0.0103
0.1397
e0.0041
e0.0713
40
e0.0299
e0.4328
e0.0284
e0.2721
0.0107
0.1242
e0.0031
e0.0534
45
e0.0497
e0.4340
e0.0321
e0.2571
0.0093
0.1032
e0.0017
e0.0333
50
e0.0663
e0.4301
e0.0335
e0.2385
0.0078
0.0821
e0.0001
e0.0112
55
e0.0796
e0.4214
e0.0340
e0.2165
0.0052
0.0567
0.0017
0.0126
60
e0.0897
e0.4080
e0.0324
e0.1915
0.0025
0.0313
0.0033
0.0376
65
e0.0967
e0.3904
e0.0293
e0.1638
0.0031
0.0031
0.0046
0.0636
70
e0.1008
e0.3688
e0.0250
e0.1338
0.0037
e0.0252
0.0055
0.0901
75
e0.1020
e0.3435
e0.0197
e0.1020
e0.0028
e0.0548
0.0056
0.1167
80
e0.1006
e0.3150
e0.0136
e0.0688
e0.0092
e0.0843
0.0049
0.1431
85
e0.0968
e0.2837
e0.0069
e0.0346
e0.0107
e0.1134
0.0031
0.1688
90
e0.0908
e0.2500
0
0
e0.0121
e0.1425
95
e0.0830
e0.2144
0.0069
0.0416
e0.0114
e0.1694
e0.0031
e0.1688
100
e0.0735
e0.1774
0.0135
0.0688
e0.0107
e0.1963
e0.0049
e0.1431
0
0.1935
105
e0.0627
e0.1394
0.0198
0.1020
e0.0074
e0.2194
e0.0057
e0.1167
110
e0.0508
e0.1011
0.0250
0.1338
e0.0033
e0.2425
e0.0055
e0.0901
115
e0.0381
e0.0627
0.0293
0.1638
0.0041
e0.2603
e0.0046
e0.0636
120
e0.0250
e0.0250
0.0324
0.1915
0.0114
e0.2781
e0.0033
e0.0376
125
e0.0016
0.0118
0.0340
0.2165
0.0107
e0.1060
e0.0017
e0.0126
130
0.0116
0.0471
0.0335
0.2385
0.0100
0.0661
0.0001
0.0112
135
0.0145
0.0804
0.0321
0.2571
0.0083
0.0448
0.0017
0.0333
140
0.0268
0.1115
0.0284
0.2721
0.0066
0.0234
0.0031
0.0534
145
0.0382
0.1398
0.0225
0.2831
0.0045
0.0104
0.0041
0.0713
150
0.0486
0.1551
0.0145
0.2900
0.0024
e0.0026
0.0045
0.0867
155
0.0577
0.1870
0.0042
0.2926
e0.0005
e0.0213
0.0043
0.0993
160
0.0654
0.2053
e0.0083
0.2908
e0.0015
e0.0399
0.0033
0.1089
165
0.0715
0.2198
e0.0225
0.2845
e0.0028
e0.0484
0.0015
0.1155
170
0.0760
0.2301
e0.0398
0.2736
e0.0041
e0.0569
e0.0012
0.1188
175
0.0787
0.2366
e0.0587
0.2584
e0.0046
e0.0597
e0.0048
0.1188
180
0.0796
0.2387
e0.0795
0.2387
e0.0051
e0.0626
e0.0093
0.1156
Transportation and Erection of Pressure Vessels
687
688
Pressure Vessel Design Manual
Design of Vessel for Choker (Cinch) Lift at Base
• Uniform load, p.
p ¼
T
R
• Moments in ring at points A and C.
MA ¼ 0:1271TR
Mc ¼ 0:0723TR
• Tension/compression forces in ring at points A
and C.
TA ¼ 0:6421T
Tc ¼ 1:2232T
• Combined stress at point A, inside of ring.
sA ¼
TA MA
þ
A
Zin
• Combined stress at point A, outside of ring.
sA ¼
TA MA
A Zout
• Combined stress at point C, inside of ring.
sc ¼
Tc Mc
þ
A Zin
• Combined stress at point C, outside of ring.
sc ¼
Tc Mc
A Zout
Note: Assume that the choker is attached immediately at
the base ring even though this may be impossible to
achieve. Then use the properties of the base ring for A
and Z.
From R. J. Roark, Formulas for Stress and Strain, 5th
Edition, McGraw-Hill Book Co., Table 17, Cases 12 and
18 combined.
Transportation and Erection of Pressure Vessels
689
Design of Tailing Lugs
Table 10-8
Dimensions for tailing lugs
Tail Load (kips)
tL
tP
E
<10
10 to 20
21 to 40
41 to 70
71 to 100
101 to 130
131 to 170
171 to 210
211 to 250
251 to 300
>300
Ro
RP
D1
e
NR
3.5
3.5
4.5
4.5
4.5
5.5
5.5
5.5
2.375
2.375
2.375
3.4375
3.4375
3.4375
4.5
4.5
4.5
NR
0.3125
0.3125
0.3125
0.3125
0.375
0.375
0.4375
0.5
None required
0.75
0.75
1
1
1.5
1.625
1.625
2
2.25
NR
0.375
0.5
0.5
0.5
0.75
0.75
0.75
1
3
3
3
4
4
4
5
5
5
4
4
4
5
5
5
6
6
6
Special design required
690
Pressure Vessel Design Manual
Formulas
The tailing lug is designed like all other lugs. The
forces are determined from the tailing load, T, calculated per this procedure. The ideal position for the
tailing lug is to be as close as possible to the base
plate for stiffness and transmitting these loads through
the base to the skirt. The option of using a tailing lug
versus a tailing beam is the designer’s choice. Either
can accommodate internal skirt rings, stiffeners, and
struts.
Design as follows:
• Area required at pin hole, Ar.
T
Ar ¼
Fs
• Area available at pin hole, Aa.
Aa ¼ ðAtL Þ-ðD1 tL Þ
• Bending moment in lug, Mb.
Mb ¼ f L E
• Section modulus of lug, Z.
tL A2
6
• Bending stress in lug, sb.
Z ¼
Mb
Z
• Area required at pin hole for bearing, Ar.
sb ¼
Ar ¼
T
Fp
• Area available at pin hole for bearing, Aa.
Aa ¼ D2 tL
Note: Substitute tL þ 2tp for tL in the preceding equations
if pad eyes are used.
Transportation and Erection of Pressure Vessels
Procedure 10-6: Design of Top Head and Cone Lifting Lugs
Design of Top Head/Cone Lug
Dimensions
NT ¼
B2
A þ 2B
L T ¼ E þ B NT
q1 ¼ arctan
L2 ¼
2L1
A
L1
sin q1
q2 ¼ arcsin
R3
L2
q3 ¼ q1 þ q2
L3 ¼
R3
sin q3
L4 ¼ 0:5A L1 0:5D3
tan q3
L5 ¼ 0:5A L1 C
tan q3
691
692
Pressure Vessel Design Manual
Lug
Check Welds
• Maximum bending moment in lug, ML.
ML ¼ PE
• Section modulus, lug, Z.
A2 tL
6
Z ¼
• Bending stress, lug, sb.
sb ¼
ML
Z
• Thickness of lug required, tL.
tL ¼ 6ML
A2 Fb
• Tension at edge of pad, sT.
sT ¼
PL
2L4 tL
• Net section at pin hole, Ap.
Ap ¼ 2L3 tL þ 2tp D3 D1
• Shear stress at pin hole, s.
s ¼
An ¼ t L
D1
D3 D1
R3 þ 2tp
2
2
• Shear stress at top of lug, s.
ðA1 þ L6 Þ3
6
ðA þ 2BÞ3 B2 ðA þ BÞ2
¼
12
ðA þ 2BÞ
Jw ¼
Lug : Jw
• Moment, M1.
M1 ¼ LT PT
Lug Weld
f1 ¼
PT
A þ 2B
• Transverse shear due to M1, f2.
f2 ¼
M1 ðB NT Þ
Jw
• Longitudinal shear due to M1, f3.
PT
An
• Pin bearing stress, sp.
sp ¼
Re-pad :
• Find loads on welds.
• Transverse shear due to PT, f1.
PL
Ap
• Net section at top of lug, An.
s ¼
• Polar moment of inertia, Jw.
PT
D3 tL þ 2tp
M1 B
Jw
• Combined shear load, fr.
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
f r ¼ ðf 1 þ f 2 Þ2 þf 23
f3 ¼
Transportation and Erection of Pressure Vessels
• Size of weld required, w1.
fr
w1 ¼
0:707Fs
Note: If w1 exceeds the shell plate thickness, then a re-pad
must be used.
Re-pad Weld
• Moment, M2.
Pad Eye Weld
• Unit shear load on pad, f4.
f4 ¼
PT tp pD2
2tp þ tL
• Size of weld required, w3.
w3 ¼
f4
0:707Fs
M2 ¼ PT ðE þ 0:5L6 Þ
Top Head Lug for Large Loads
• Transverse shear due to PT, f1.
f1 ¼
PT
2A1 þ 2L6
• Transverse shear due to M2, f2.
f2 ¼
0:5M2 L6
Jw
• Longitudinal shear due to M2, f3.
f3 ¼
M2 L6
Jw
• Combined shear load, fr.
fr ¼
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
ðf 1 þ f 2 Þ2 þf 23
• Size of weld required, w1.
fr
w2 ¼
0:707Fs
693
694
Pressure Vessel Design Manual
Table 10-9
Dimensions for top head or cone lugs
Transportation and Erection of Pressure Vessels
Procedure 10-7: Design of Flange Lugs
695
696
Pressure Vessel Design Manual
Table 10-10
Flange lug dimensions
Load Capacity (tons)
D1
tL
tb
A
B
G
H
E
50
100
200
400
600
800
3.38
5
6
8
9
10
2
3
4
5
6
9
2
3
4
5
6
7
8
14
18
20
24
28
11
12
14
16
22
24
12
24
30
36
40
42
30
36
40
46
58
60
9
9
10
11
16
17
Table 10-11
Bolt properties
Bolt Size
Ab
As
Tb
0.5e13
0.625e11
0.75e10
0.875e9
1e8
1.125e8
1.25e8
1.375e8
1.5e8
1.75e8
2e8
2.25e8
2.5e8
2.75e8
3e8
3.25e8
3.5e8
3.75e8
4e8
0.196
0.307
0.442
0.601
0.785
0.994
1.227
1.485
1.767
2.405
3.142
3.976
4.909
5.94
7.069
8.3
9.62
11.04
12.57
0.112
0.199
0.309
0.446
0.605
0.79
1
1.233
1.492
2.082
2.771
3.557
4.442
5.43
6.506
7.686
8.96
10.34
11.81
12
19
28
39
51
56
71
85
103
182
243
311
389
418
501
592
690
796
910
Table 10-12
Values of Su
Bolt Dia, db
Material
Su (ksi)
<1
1.125e1.5
1.625e2.5
2.625e4
A-325
A-325
A-193-B7
A-193-B7
120
105
125
110
Transportation and Erection of Pressure Vessels
Top Flange Lug
Side Flange Lug
PL ¼ P sin q
PT ¼ P cos q
PE ¼
PL 3PT e
þ 2
A
A
M1 ¼ PTB
Fn ¼
fs ¼
PT
N
sT ¼
Fn
As
M2 ¼ PT(B þ J)
M3 ¼ PTe
Mu ¼ Xn cos an Nb
Mu M1
Ma ¼ P
Mu
Ma
Xn Nb
Fs ¼ 15 ksi
s T Ab
1
Tb
As ¼ 0:7854 ðd 0:1218Þ2
s ¼
fs
< Fs
As
Xn ¼ Rb cos an
Tb ¼ 0:75u As
yn ¼ Rb sin an
0:6Fy < FT < 40 ksi
697
698
Pressure Vessel Design Manual
Design Process
Maximum Tension in Lug
1. Determine loads
2. Check of lug:
a. Shear at pin hole.
b. Bending of lug.
c. Bearing at pin hole.
3. Check of base plate.
4. Check of nozzle flange.
5. Check of flange bolting.
6. Check of local load at nozzle to head or shell
junction.
Step 1: Determine loads.
• Determine loads PT and PL for various lift angles, q.
• Determine uniform loads w1 and w2 for various
angles, q.
• Using w1 and w2, solve for worst case of combined
load, PE.
• Determine worst-case bending moment in lug, M3.
Step 2: Check of lug.
a. Shear at pin hole:
• Area required, Ar.
Ar ¼
PE
Fs
Check of Nozzle Flange
• Area available at pin hole, Aa.
Aa ¼ ðAtL Þ ðD1 tL Þ
b. Bending of lug due to M3:
• Section modulus, Z.
Z ¼
tL A2
6
• Bending stress, lug, sb.
sb ¼
M3
Z
c. Bearing at pin hole:
• Bearing required at pin hole Ar.
Ar ¼
PE
Fp
• Bearing available, Aa.
Aa ¼ D 2 t L
• Unit load, w.
PE
pBc
• Bending moment, M.
w ¼
M ¼ whD
• Bending stress, sb.
sb ¼
6M
t2f
Transportation and Erection of Pressure Vessels
Bolt Loads for Rectangular Lugs
699
Design of Full Circular Base Plate for Lug
• If a full circular plate is used in lieu of a rectangular
plate, the following evaluation may be used.
• Unit load on bolt circle, w.
w ¼
PE
pBc
• Edge distance from point of load, hp.
hp ¼
BC tL
2
• Bending moment, M.
M ¼ whp
• Bending stress, sb.
sb ¼
6M
t2b
• Check bolting same as rectangular flange.
700
Pressure Vessel Design Manual
Design of Lug Base Plate
(From R. J. Roark, Formulas for Stress and Strain,
McGraw-Hill Book Co, 4th Edition, Table III, Case 34.)
• Uniform load, w.
w ¼
PE
A
• End reaction, R1.
R1 ¼
wA
2
• Edge moment, Ma.
Ma ¼
wA 24R3c 6ðb þ AÞA2 3A3
þ
þ 4A2
Bc
Bc
24Bc Bc
24R2c
• Moment at midspan, Mx.
#
"
wA ðRc bÞ2
Mx ¼ Ma þ R1 Rc A
2
• Thickness required, tb.
sffiffiffiffiffiffiffiffiffi
6Mx
tb ¼
GFb
Transportation and Erection of Pressure Vessels
Check of Bolts
Case 1: Bolts on Centerline
Bolt
1
2
3
Case 2: Bolts Straddle Centerline
4
5
Bolt
an
an
xn
xn
yn
yn
Nb
Nb
Mu
Mu
Ma
Ma
Fn
Fn
sT
sT
Fs
Fs
1
2
3
4
5
701
702
Pressure Vessel Design Manual
Sample Problem: Top Flange Lug
Given
L1
L2
L3
L4
Fy bolting
Fy lug
Fy flange
Fs
FT
Fb
WL
Bc
Rc
B
tb
tL
tf
D1
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
¼
90 ft
50 ft
40 ft
9.5 ft
75 ksi
36 ksi
36 ksi
0.4(36) ¼ 14.4 ksi
0.6(36) ¼ 21.6 ksi
0.66(36) ¼ 23.76 ksi
1200 kips
54 in.
27 in.
22 in.
6 in.
6 in.
11 in.
9 in.
D2 ¼ 8 in.
Bolt size ¼ 3-1/4-8 UNC
Ab ¼ 8.3 in.2
As ¼ 7.686 in.2
Tb ¼ 592 kips
Su ¼ 110 ksi
e
G
A
hD
b
¼
¼
¼
¼
¼
16 in.
40 in.
24 in.
9.5 in.
0:5ðBc AÞ
Results
PT max ¼ 537 kips @ q ¼ 10
PL max ¼1200 kips @ q ¼ 90
PE max ¼1277 kips @ q ¼ 40
sT bolt, max ¼ 20.11 ksi 40 ksi
s bolt, max ¼ 6.98 ksi 10.77 ksi
Transportation and Erection of Pressure Vessels
703
704
Pressure Vessel Design Manual
• Edge moment, Ma.
1.0 Check Lug
a. Shear at pin hole:
Ma ¼
• Area required, Ar.
Ar ¼
PE
1277
¼
¼ 88:68 in:2
FS
14:4
24R2c
• Area available at pin hole, Aa.
Aa ¼ ðAtL Þ ðD1 tL Þ ¼ ð24$6Þ ð9$6Þ ¼ 90 in:
b. Bending of lug due to M3:
• Maximum moment, M3.
M3 ¼ PT e ¼ 537ð16Þ ¼ 8592 in: kips
• Section modulus, Z.
6$242
tL A2
Z ¼
¼
¼ 576 in:3
6
6
• Bending stress, lug, sb.
sb ¼
M3
8592
¼
¼ 14:91 ksi
Z
576
• Thickness required, tL.
tL ¼
6M
6$8592
¼ 3:76 in:
¼
2
23:76ð242 Þ
Fb A
c. Bearing at pin hole:
• Bearing required at pin hole, Ar.
Ar ¼
PE
1277
¼
¼ 39:41 in:2
FP
32:4
• Bearing available, Aa.
Aa ¼ D2 tL ¼ 8$6 ¼ 48 in:2
Ma ¼ 0:985ð8748 2496 þ 768 þ 2304 17; 496Þ
2
¼ 8049 in: kips
• Moment at mid, Mx.
#
"
wA ðRc bÞ2
Mx ¼ Ma þ R1 Rc A
2
Mx ¼ 8049 þ 17; 240 3831
¼ 5360 in: kips
• Section modulus, Z.
2 2 tb G
6 $40
Z ¼
¼
¼ 240 in:3
6
6
• Bending stress, sb.
sb ¼
PE
1277
kips
¼
¼ 53:2
A
24
in:
• End reaction, R1.
w ¼
R1 ¼
PE
1277
¼
¼ 638:5 kips
2
2
Mx
5360
¼
¼ 22:33 ksi
Z
240
• Allowable bending stress, Fb.
Fb ¼ 0:66Fy ¼ 0:66 36 ¼ 23:76 ksi
3.0 Check of Vessel Flange
• Unit load, w.
w ¼
2.0 Check Lug Base Plate
• Uniform load, w.
wA 24R3c 6ðb þ AÞA2 3A3
þ
þ 4A2
Bc
Bc
24Bc Bc
PE
1277
kips
¼
¼ 7:52
pBc
p54
in:
• Bending moment, Mb.
Mb ¼ whD ¼ 7:52ð9:2Þ ¼ 69:25 in: kips
• Bending stress, sb.
sb ¼
6Mb
½6ð69:25Þ
¼
¼ 3:28 ksi
2
11:252
tf
Transportation and Erection of Pressure Vessels
705
706
Pressure Vessel Design Manual
Procedure 10-8: Design of Trunnions
Lug Dimensions
Type 1: Trunnion and Fixed Lug
Type 2: Trunnion and Rotating Lug
Dimensions for Trunnion
Type 3: Trunnion Only
Transportation and Erection of Pressure Vessels
Type 1: Trunnion and Fixed Lug
There are four checks to be performed:
1.
2.
3.
4.
Check
Check
Check
Check
lug.
trunnion.
welds.
vessel shell.
and Z ¼
4R2o tL
6
MT
2pRn to
sT ¼
Check Welds
• Section modulus of weld, Sw.
Sw ¼ pR2n
1:5PT E
R2o Fb
• Polar moment of inertia, Jw.
Longitudinal (vessel vertical)
• Cross-sectional area at pin hole, Ap.
Ap ¼ 213 tL þ 2tp ðD3 D1
• Cross-sectional area at top of lug, An.
An ¼ tL
D1
D3 D1
RT þ 2tp
2
2
• Shear stress, s.
PL
AP
or
Jw ¼ 2pR3n
• Shear stress in weld due to bending moment, fs.
fs ¼
ML
Sw
• Torsional shear stress in weld, sT.
sT ¼
MT Rn
Jw
• Size of welds required, w1 and w2.
s ¼
PL
An
• Pin bearing stress, sp.
sp ¼
ML
Z
• Torsional shear stress, sT.
Therefore,
s ¼
MT ¼ PT E
sb ¼
Transverse (vessel horizontal)
tL ¼
• Torsional moment, MT (vessel horizontal).
• Bending stress, sb.
Check Lug
M ¼ PT E
707
PL
D2 tL þ 2tp
Check Trunnion
• Longitudinal moment, ML (vessel vertical).
ML ¼ PL e
w1 > thickness of end plate
w2 ¼ width of combined groove and fillet welds
w2 ¼
fs
Fs
3
> in:
8
Type 2: Trunnion and Rotating Lug
• Net section at Section A-A, Ap.
Ap ¼ 213 tL þ 2tp D3 D1
708
Pressure Vessel Design Manual
• Shear stress at pin hole, s.
s ¼
PL
Ap
Vessel Vertical
• Net section at Section B-B, An.
An ¼ 2tL ðRo Ri Þ
• Shear stress at trunnion, s.
s ¼
• Minimum bearing contact angle for lug at trunnion, qB.
ð15:9PL Þ
Rn tL Fp
• Pin hole bearing stress, sp.
sp ¼
• Longitudinal moment, ML.
ML ¼ P L e
• Bending stress in trunnion, sb.
ML
Z
sb ¼
PL
An
qB ¼
Type 3: Trunnion Only
PL
D3 tL þ 2tp
Vessel Horizontal
• Circumferential moment, Mc.
Mc ¼ PT e
• Bending stress in trunnion, sb.
Mc
Z
sb ¼
Check Welds
Check Welds
• Longitudinal moment, ML (vessel vertical).
ML ¼ PL e
Sw ¼ pR2n
• Shear stress in weld due to bending moment, fs.
ML
fs ¼
Sw
• Size of welds required, w1 and w2.
w1 > thickness of end plate
w2 ¼ width of combined groove and fillet welds
fs
Fs
ML ¼ PL e
• Section modulus of weld, Sw.
• Section modulus of weld, Sw.
w2 ¼
• Longitudinal moment, ML (vessel vertical).
3
> in:
8
Sw ¼ pR2n
• Shear stress in weld due to bending moment, fs.
fs ¼
ML
Sw
• Size of welds required, w1 and w2.
w1 > thickness of end plate
w2 ¼ width of combined groove and fillet welds
w2 ¼
fs
Fs
3
> in:
8
Transportation and Erection of Pressure Vessels
709
Table 10-13
Dimensions of trunnions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Allowable Load, Tons
Pipe Size "A"
C
D
E
F
M
N
T
W
Weight, Lbs
0-5
5-10
10-15
15-25
25-35
35-45
45-60
60-75
75-100
100-125
125-150
150-200
200-250
300
400
500
600
4" Std
6" Std
8" Std
10" Std
12" Sch 80
12" Sch 80
14" Sch 80
14" Sch 80
16" Sch 80
16" Sch 80
18" Sch 80
18" Sch 80
20" Sch 80
24" Sch 80
24" Sch 80
30" 1.25"
36" 1.25"
4
5
6
6
6
6
6
7
7
7
7
8
8
8
8
10
10
0.625
0.625
0.75
0.75
0.75
0.875
0.875
0.875
0.875
0.875
0.875
1
1
1.25
1.25
8
8
8
8
8
8
8
8
8
8
10
10
10
12
12
8.5
10.5
12.5
15
17
17
18
18
25
25
27
27
30
34
34
42
48
8
12
15
18
21
21
24
24
27
27
30
30
36
36
40
48
60
4
4
4
4
8
8
8
8
12
12
16
16
20
20
24
0.5
0.5
0.5
0.75
0.75
0.75
1
1
1
1.125
1.125
1.125
1.25
1.25
1.375
1.375
1.5
0.25
0.25
0.375
0.375
0.375
0.5
0.5
0.625
0.625
0.875
0.875
1
1
1.125
1.125
1.375
1.375
30
55
90
150
240
240
375
400
625
660
850
875
1000
1440
1675
2400
3600
Notes:
1.
2.
3.
4.
Do not use re-pads for cyclic service
B ¼ D - .125
K ¼ Pipe Wall Thk
Dimensions are given for reference only. All loadings and stress shall be checked prior to use.
W
W
K
2.50
NUTS WELDED
DIA = F
1.25
DIA A
B
DIA = M
DIA = F
DIA A
DIA = M
D
K
K
K
K
2 X .125 DIA
VENT HOLES
T
C
TYPE 1
K
2 X .125 DIA
VENT HOLES
GRIND WELD
SMOOTH
T
E
TYPE 2
710
Pressure Vessel Design Manual
Procedure 10-9: Local Loads in Shell Due to Erection Forces
Trunnions
Rotating Trunnion
Fixed Lug Trunnion
• Maximum longitudinal moment, Mx.
Mx ¼ PL e
• Maximum circumferential moment, Mc.
Mc ¼ P T e
• Loads for any given lift angle, q.
PL ¼ 0:5P sin q
PT ¼ 0:5P cos q
TrunniondNo Lug
• Maximum longitudinal moment, Mx.
Mx ¼ PL e
• Maximum circumferential moment, Mc.
Mc ¼ PT e
• Maximum torsional moment, MT.
MT ¼ PT E
• Loads for any given lift angle, q.
PL ¼ 0:5P sin q
PT ¼ 0:5P cos q
• Maximum longitudinal moment, Mx.
Mx ¼ PL e
• Maximum circumferential moment, Mc.
Mc ¼ P T e
• Loads for any given lift angle, q.
PL ¼ 0:5P sin q
PT ¼ 0:5P cos q
Transportation and Erection of Pressure Vessels
Side Lugs
711
Notes:
1. Optional internal pipe. Remove after erection.
2. Radial load, Pr, is the axial load in the internal pipe
stiffener if used in lieu of radial load in shell.
3. Circumferential ring stiffeners are optional at these
elevations.
• Circumferential moment, Mc.
Mc ¼ PT e
• Longitudinal moment, Mx.
Mx ¼ PL e
• Load on weld group, f.
PT E
LT
• Radial loads, Pr and Pa.
f ¼
Pr ¼ PL e
Pa ¼ PL sin f
Top Flange Lug
• Loads, PT and PL.
PT ¼ P cos q
PL ¼ P sin q
712
Pressure Vessel Design Manual
• Moment on flange, M.
M ¼ PT B
• Moment on head, M.
M ¼ PT ðB þ JÞ
• Moment on vessel, M.
M ¼ PT G
• Radial load on head and nozzle ¼ PL.
Side Flange Lug
• Loads, PT and PL.
PL ¼ P cos q
PT ¼ P sin q
• Moment on flange, M.
M ¼ PL B
• Longitudinal moment on shell, Mx.
M ¼ PT ðB þ JÞ
• Radial load on shell and nozzle ¼ PT.
Transportation and Erection of Pressure Vessels
713
Procedure 10-10: Miscellaneous
Figure 10-7. Fundamental handling operations. Reprinted by permission of the Babcock and Wilcox Company,
a McDermott Company.
714
Pressure Vessel Design Manual
Figure 10-8. Loads on wire rope for various sheave configurations.
Transportation and Erection of Pressure Vessels
715
Table 10-14
Forged Steel Shackles
Dimensions in Inches
Size D (in.)
Safe Load
(lb)
D (min)
A
Tolerance
A Dim.
B
B (min)
C
G
Tolerance C
and G Dim.
E
F
¼
475
7
15
1/ 16
5
9
1⅛
⅞
1/ 16
¾
11
⅜
1,050
11
21
1/ 16
7
/ 16
25
17/ 16
1¼
⅛
1
31
7
/ 16
1,450
25
23
1/ 16
½
29
111/ 16
17/ 16
⅛
1⅛
11/ 16
½
1,900
29
13
/ 16
1/ 16
⅝
9
1⅞
1⅝
⅛
1⅜
15/ 16
⅝
2,950
9
11/ 16
1/ 16
¾
43
213/ 32
2
⅛
1⅝
19/ 16
¾
4,250
43
1¼
1/ 16
⅞
25
227/ 32
2⅜
¼
2
1⅞
⅞
5,750
25
17/ 16
1/ 16
1
57
/ 64
35/ 16
213/ 16
¼
2¼
2⅛
1
7,550
57
/ 64
111/ 16
1/ 16
1⅛
11/ 32
3¾
33/ 16
¼
2½
2⅜
1⅛
8,900
11/ 32
127/ 16
⅛
1¼
17/ 64
4¼
39/ 16
¼
2¾
2⅝
1¼
11,000
17/ 64
21/ 32
⅛
1⅜
115/ 64
411/ 16
315/ 16
¼
3⅛
3
1⅜
13,300
115/ 64
2¼
⅛
1½
111/ 32
5¼
47/ 16
¼
3½
35/ 16
1½
15,600
111/ 32
2⅜
⅛
1⅝
129/ 64
5¾
4⅞
¼
3¾
3⅝
1¾
21,500
135/ 64
2⅞
⅛
2
125/ 32
7
5¾
¼
4¼
4⅛
2
28,100
125/ 32
3¼
⅛
2¼
21/ 64
7¾
6¾
¼
5¼
5
2¼
36,000
21/ 64
3¾
⅛
2½
215/ 64
9¼
7⅛
¾
5½
5¼
2½
45,100
215/ 64
4⅛
⅛
2¾
215/ 32
10½
8
¾
6¼
6
3
64,700
211/ 16
5
⅛
3¼
229/ 32
13
11½
¾
6¾
6½
/ 32
/ 32
/ 64
/ 64
/ 16
/ 64
/ 32
/ 32
/ 32
/ 32
/ 16
/ 32
/ 64
/ 64
/ 16
/ 64
/ 32
/ 16
/ 32
Notes:
For shackles with safe loads greater than the maximum shown, use Crosby–Laughlin (The Crosby Group, Div. of American Hoist & Derrick Co, Tulsa,
OK 74101), Skookum (Skookum Co., Inc., Portland, OR 97203), or equal with an ultimate strength at least 5 times the safe working load.
Allowable loads are lower than OSHA requirements tabulated in Section 1926.251, Table H-19.
716
Pressure Vessel Design Manual
Figure 10-9. Wire rope end configurations.
Transportation and Erection of Pressure Vessels
717
Table 10-15
Material transportation and lifting
Material-Handling
System
Site Transport:
Flatbed trailers
Extendable
trailers
Lowboy and
dropdeck
Crawler
transporter
Straddle carrier
Rail
Roller and track
Plate and slide
Air bearings or
air pallets
High line
Lifting:
Chain hoist
Hydraulic rough
terrain cranes
Hydraulic truck
cranes
Lattice boom
truck cranes
Lattice boom
crawler cranes
Fixed position
crawler cranes
Tower gantry
cranes
Guy derrick
Chicago boom
Stiff leg derrick
Monorail
Jacking systems
Description
Capacity t (tm)
Bed dimension 8 40 ft (2.4 12.2m)ddeck height 60 in. (1524 mm) used to transport
materials from storage to staging area.
Bed dimension up to 8 60 ft (2.4 18.3m)ddeck height 60 in. (1524 mm) used to
transport materials from storage to staging area.
Bed dimension up to 8 40 ft (2.4 12.2m)ddeck height of 24 in. (610 mm) used to
transport materials from storage to staging area.
Specially designed mechanism for handling heavy loads; Lampson crawler transporter,
for an example of the Lampson design.
Mobile design to transport structural steel, piping, and other assorted items; straddle
carrier, for an example of this design.
Track utilized to transport materials to installed location. Continuous track allows material
in-stallation directly from delivery car.
Steel machinery rollers located relative to component center of gravity handle the load.
Rollers traverse the web of a channel welded to top flange of structural member below.
Sliding steel plates. Coefficient of frictiond0.4 steel on steel, 0.09 greased steel on steel,
0.04 Teflon on steel. Sliding plate transport for movement of 1200 t (1089 tm) vessel.
Utilizes film of air between flexible diaphragm and flat horizontal surface. Air flow 3 to 200
ft3/min (0.001 to 0.09 m3/s). 1 lb (4.5N) lateral force per 1000 lb (454 kg) vertical load.
Taut cable guideway anchored between two points and fitted with inverted sheave and
hook.
Chain operated geared hoist for manual load handling capability. Standard lift heights 8 to
12 ft (2.4 to 3.7m).
Telescopic boom mounted on rubber tired self-propelled carrier.
20 (18)
90 (82)
Telescopic boom mounted on rubber tired independent carrier.
450 (408)
Lattice boom mounted on rubber tired independent carrier.
800 (726)
Lattice boom mounted on self-propelled crawlers.
2200 (1996)
Lattice boom mounted on self-propelled crawlers and equipped with specifically designed
attachments and counterweights.
Tower mounted lattice boom gantry for operation above work site.
750 (680)
Boom mounted to a mast supported by wire rope guys. Attached to existing building steel
with load lines operated from independent hoist. Swing angle 360 deg (6.28 rad).
Boom mounted to existing structure which acts as mast, and to which is attached boom
topping lift and pivoting boom support bracket. Load lines operated from independent
hoist. Swing angle from 180 to 270 deg (3.14 to 4.71 rad).
Boom attached to mast supported by two rigid diagonal legs and horizontal sills.
Horizontal angle between each leg and sill combination ranges from 60 to 90 deg (1.05
to 1.57 rad); swing angle from 270 to 300 deg (4.71 to 5.24 rad).
High capacity load blocks suspended from trolleys which traverse monorail beams
suspended from boiler support steel. Provides capability to lift and move loads within
boiler cavity.
Custom designed hydraulic or mechanical system for high capacity special lifts.
Reprinted by permission of the Babcock and Wilcox Company, a McDermott Company.
15 (14)
60 (54)
700 (635)
30 (27)
as designed
2000 (1814)
as designed
75 (68)
5 (4.5)
25 (23)
230 (209)
600 (544)
function of
support
structure
700 (635)
400 (363)
as specified
718
Pressure Vessel Design Manual
Notes
1. This procedure is for the design of the vessel and
the lifting attachments only. It is not intended to
define rigging or crane requirements.
2. Lifting attachments may remain on the vessel after
erection unless there is some process- or interference-related issue that would necessitate their
removal.
3. Load and impact factors must be used for moving
loads. It is recommended that a 25% impact factor
and a minimum load factor of 1.5 be used. The
combined load and impact factor should be 1.5–2.0.
4. Allowable stress compression should be 0.6Fy for
structural attachments and ASME Factor “B” times
1.33 for the vessel shell.
5. Vessel shipping orientation should be established
such that a line through the lifting lugs is parallel to
grade if possible. This prevents the vessel from
having to be “rolled” to the correct orientation for
loading and offloading operations.
6. If a spreader beam is not used, the minimum sling
angle shall be 30 from the horizontal position. At
30 , the tension in each sling is equal to the total
design load. Thus a load factor of 2 is mandatory
for these cases. This requires that each lug be
designed for the full load.
7. Vessels should never be lifted by a nozzle or other
small attachments unless specifically designed to
do so.
8. All local loads in vessel shell or head resulting
from loadings imposed during erection of the
vessel shall be analyzed using a suitable local load
procedure.
9. Tailing attachment shall be designed such that they
may be unbolted without having to get under the
load while it is suspended. As an alternative, the
vessel must be set down at grade before a person
10.
11.
12.
13.
14.
15.
16.
can get under the base ring to unbolt the tailing
beam. Be advised that the base and skirt may not be
designed for point support if cribbing is used to
build up the base for access.
A tailing lug, as opposed to a tailing beam, allows
the load to be disconnected from the vessel without
a person’s getting under a suspended load to
unhook.
This procedure assumes that the pin diameter is no
less than 1/ 16 in. less than the hole diameter. If the
pin diameter is greater than 1/ 16 in. smaller than the
hole diameter, then the bearing stresses in the lug at
the contact point are increased dramatically due to
the stress concentration effect.
Internal struts in the skirt or base plate are required
only if the base/skirt configuration is overstressed.
If bearing or shear stresses are exceeded in the lug,
add pad eyes.
Trunnions may be used as tailing devices as long as
the resulting local loads in the skirt are analyzed.
Do not use less than Schedule 40 pipe for
trunnions.
Specific notes for trunnions:
a. Type 1, fixed lug: Normal use but generally for
small to medium vessels (less than 100 tons).
b. Type 2, rotating lug: Best use is when multiple
vessels are to be lifted with the same lug. The
lug may be removed by removing the end plate
and sliding the lug off. Then the lug is reinstalled on the next vessel. For heavier loads, an
internal sleeve should be attached to the lug to
increase the bearing area on the trunnion.
c. Type 3, trunnion only: No size limitation or
weight limitation. The cable and trunnions
should be lubricated prior to lifting to prevent
the cables from binding. The bend radius of the
cables may govern the diameter of the trunnion.
Check with erection contractor.