THE METHOD STATEMENT OF
MECHANICAL
HANGER AND SUPPORT
INSTALLATION
Page 1
Table of contents
1. Gross References ............................................................................. Page 3
2. Scope of works .................................................................................. Page 3
3. Flow of Works Chart........................................................................... Page 4
4. Methodology .................................................................................. Page 5-27
5. Tools and Equipment .......................................................................... Page28
6. Safety Measures ................................................................................ Page 28
7. Appendices ........................................................................................ Page 28
8. Painting Safety Fire
pipe………………………………………………………………………………………………
…Page 29
1.Gross References
Page 2
1.1 General: Refer to the general Requirements worksection
Refer to the following worksection:
Mechanical general requirements, Fire protection system, hydranlic system, air handling uint
and ventilation system.
1.2 Material:
Material for Hanger and support following the standards on specification
Approved type by Engineer
To describe mechanical works associated with install hanger and support of mechanical system to
ensure compliance with contract requirements, drawings and technical specification. The design of the
pipe work installation shall be tested and certify strictly in accordance with the requirement specification,
2. Scope of Works
Scope of works install hangers and supports of Mechanical System including the Duct
works system, Piping fire protection and Hydrandlic system. The scope of work for this method
statement shall include all the Mechanical system.
Page 3
3. Flow of Works (Flow chart):
Shop drawings
(Approved)
Material
Approved
Determine pipe as per
approved location & level
Marking
Not approved
Define position of
support
Approved
Installation of
pipe
Not approved
In-house
Inspection
Approved
Engineer ‘s
inspection
Approved
Proceed
Page 4
4. Methodology
4.1. General
4.1.1. The size of Hangers and supports shall be in compliance with the contract specification,
documents, and approved shop drawings.
4.1.2 Hangers and supports of mechanical system shall be fabricated at factory from the
approved and galvanized steel sheet roll.
4.1.3 To ensure that all Hangers and supports material are fabricated form the approved, worker
Shall take photo picture on the approved material for record, before starting any fabrication process.
When the finished parts delivery to site, the Engineer’s shall check the quality and material
used, by the Q/C labels together with the evidence of the photo picture or refer to shop drawing , on the
material been used in the fabrication.
4.1.4 Only the site engineer’s final approved Hangers and supports shall be used for the site
installation works.
4.1.5. Various hanger systems and components for system shall be used and shall be
Coordinated with the ceiling work at the Contractor option with the approval by the Mechanical
engineer.
4.1.6 All flanged joints shall be provided with suitable gasket as approved type by the Engineer.
4.1.7 Supports shall be attached to every system using screws or bolt to prevent slippage and
noise.
4.1.8.Wall or overhead supports shall be anchored to structure using bolts of suitable type and
adequate size or other methods suitable for conditions or materials encountered, only as approved by
the Engineer.
4.1.9. Supports insulation work will be mentioned on method statement for mechanical system
insulation work.
Page 5
4.2. Hangers and Supports for duck work systems
4.2.1 Supports and hangers shall be L-type formed steel angles, shall be as shown in Table 1
The vibration isolation rod hanger for fans shall be indicated on shop drawings.
Table 1 Hangers and Supports Schedule ( Refer to AS 4254)
Duct Size
Largest
Dimension
(mm)
Up to 900
Size of L-type
Hanger rods
Hanger
Hanger
formed steel
diameter
Maximum
Maximum
angle
(minimum)
spacing for
spacing for
(minimum)
(mm)
Flange Joint
TDC Joint
(mm)
(mm)
(mm)
30 x 30 x 3
8mm
3,000mm
1500mm
901 to 1600
40 x 40 x 3
10mm
3,000mm
1500mm
1601 to 2200
40 x 40 x 3
12mm
2,400mm
-
Over 2,200
50 x 50 x 3
12mm
2,400mm
-
W + 30
Insertion
Anchor bolt
(Appro type
by the ICE)
W
Hanger
rod-galvanize
is use
area normal
L1 to L24.
B3, B2, B1,
Roof use rod
Inox or rod Hot
div galvanize
L - type formed steel angle
W - Include the thickness of insulation
Figure 1: Section of Hangers and Supports
(Detail refer to drawing SRF-DT-500)
Note:
a) Hangers and supports details please refer to approved shop drawings.
Page 6
Figure 2 Details of Hangers and Supports of Duct work for Riser
(Detail refer to Table HS.5 of MOS hanger support)
(SEE TO FILE AUTOCAD)
4.2.2. Fix Support
4.2.2.1. Check length of duct round and weight according to Table 12-1,12-2.
4.2.2. According to Table 3, select the Steel angle and Anchor bolt. Steel angle must be fabricated at
factory.
4.2.3. Fix support must be fixed to slab or beam.
Page 7
4.2.2.4. Spacing of Fix support by steel angle shall be 1500mm and below, or refer to shop drawing
approved.
Anchor bolt (Approved type by the engineer)
L-type formed steel angle
Beam
Duct including
insulation
Figure 7: Section of Fix support
(Detail refer to table HS.5))
Note:
Fix supports details please refer to approved shop drawings.
Table. 2 Size of Steel Angle and Anchor Bolt
(refer to AS 4254)
Steel angle length - L
Steel angle Size(minimum)
Up to 1000
L-30×30×2.5
M×8
Up to 1600
L-50×50×3.0
M×10
Up to 2200
L-50×50×4.0
M×12
Over 2200
L-50×50×5
M×12
Anchor Bolt size Slab (mm)
Note: Fix supports details please refer to approved shop drawings.
4.2.3 Plenum Chamber
Plenum Chamber Thickness:
- Thickness for galvanized steel sheet shall be as shown in Shop drawing approved
4.2.3 Reinforcing
- Requirements for Size of L-type formed steel angle reinforcing shall be as shown in Table 4.
Page 8
Table 4. Size of L-type formed steel angle Reinforcing
Size of L-type formed
Largest Dimension of
steel angle
Maximum Spacing
Plenum Chamber (mm)
Size (minimum)
(mm)
(mm)
Up to 1000
L-30×30×2.5
1500
Up to 1600
L-50×50×3.0
1500
Up to 2200
L-50×50×4.0
1500
Over 2200
L-50×50×5
1500
Notes
- Installation details shall be indicated on shop drawings.
- Details of plenum chamber shall be indicated on the shop drawings.
Page 9
4.3. Pipe Hangers and support for system
- Piping or equipment supported by wire, plumber’s tape, rope or other means or arrangements shall not
be permitted.
- Pipe or equipment supported by valves or other line accessories shall not be permitted.
a) Vertical piping shall be supported as follows:
i)
Risers: Steel angle support to rest at least on refer to shop drawing approved
ii)
Copper pipe: Steel angle support with rubber and refer to shop
b) Horizontal piping shall be supported as follows:
Pipes shall be attached to or supported from structure using hangers and devices as specified or
approved.
c) Hanger and Fix support spacing shall be as the following Table 5.
Table 5: Hanger and Fix support spacing
Diameter
Type
15
20
25
32
Carbon
Steel Pipe
Hang
Spacing
Fix
Support
Spacing
Polyvinyl
chloride
pipe
Copper
pipe
Carbon
Steel Pipe
Polyvinyl
chloride
pipe
Copper
pipe
40
50
65
80
100
125
150
200
250
2.0 m or less
3.0 m or less
1.5 m or less
1.2 m or less
1.5 m or less
1.5 m or less
Span by span
or less
___
300
1.5m or Show on Shop
Drawing
___
Span by span
or less
Span by span or
less
1.5m or Show on Shop
1.5m or Drawing
___
Span by span
or less
Span by span or
less
1.5m or Show on Shop
Drawing
d) Low temperature pipe insulation shall be required for refrigerant lines and chilled water lines at
points of support between pipe and hanger using rebar sheet or wood approved.
e) Copper pipe isolation shall be required for each point of contact with hangers or other ferrous
materials.
f) Hanger rods
i)
Hanger rod size shall be as the following Table 6:
Table 6: Hanger rod size (Item B of Spection)
Supported pipe (mm)
Rod diameter (mm)
<20
06
20 to <100
10
Page 10
100 to 120
12
>120 to 275
16
>275 to 325
20
Over 325
24
Table 10 U bolt Size (Spection)
Diameter Pipe
U bolt Size
16mm – 34mm
6mm
42mm – 90mm
8mm
Over 90mm
10mm
From 150 - 250
25x2mm
4.4.3. Additional Support
At changes of direction in either vertical or horizontal and point near the valve, additional support
shall be provided. However it may be omitted when coincidental with required standard spacing
location.
Page 11
Support near valve
Support
Support
Valve size is Less than 100mm
Support
Valve size is 100mm and above
Support near bent
Support near bent
Support near bent
300ｍｍ or below
300ｍｍ or below
300ｍｍ or below
Support
Support
Support near branch
45°
Support near branch
Support
600mm and above
600mm and above
Support
Figure 9. Additional support
4.4.4. Fix Support
1. Check the pipe weight, number and support spacing (Table 5).
2. According to Table 9, select the Steel angle and Anchor bolt.
3. The method of fixing for Insulated pipe is in accordance with Section8.8.
Page 12
Support
PIPE
PIPE
WELD
PIPE CUT 45 ANGLE
WELD
2
DETAIL 1
DETAIL 1
Figure 10 : Example for connect pipe over 65mm
(for Chiller water pipe)
Table 9 Size of Steel Angle and Anchor Bolt
Note: Steel angle and bolts shall be indicated on shop drawings.
Steel Angle Length
Size of Steel Angle and Anchor Bolt
Weight
(kg)
L
500
60
1000
500
120
H
Steel angle Size(minimum)
Anchor Bolt Size(minimum)
Slab
Wall
1000
L-50×50×5.5
M10×30×2
M10×30×2
1500
L-63×63×5.5
M10×30×2
-
1000
L-63×63×5.5
M10×30×2
M10×30×2
1500
L-63×63×5.5
M10×30×4
-
1000
L-70×70×6.5
M10×30×4
M10×30×2
1500
U120×48×4
M10×30×4
-
1000
L-75×75×5.5
M10×30×4
M10×30×2
1500
U150×48×4
M24×30×4
-
M10×30×4
M10×30×2
M10×30×4
-
1000
1000
1000
240
1500
1000
U120×48×4
M10×30×4
M10×30×2
1500
M10×30×4
-
1000
M10×30×4
M10×30×2
M10×30×4
-
M10×30×4
M10×30×2
1500
1000
360
1500
1500
U150×48×4
1000
Page 13
1500
M24×30×4
-
4.4.5 Setting of Floor Drain and Clean out
Setting of Floor Drain and Clean out shall be followed as under Figures.
Cap
Concrete
Slab
Steel panel
Clean out (COA)
Finishing work
(Architectural work)
Cut pipe
PVC pipe
Process 1)
1. Install pipe and steel panel.
2. Fill concrete.
Process 2)
1. Finishing work by Architectural
work.
2. Cut pipe.
(Fire stopping will be supply late)
Figure 12 Setting of Clean out Type A
Page 14
Process 3)
Install COA ( upper part ).
Cap
Water proofing
(Architectural work)
Steel panel
Connect Sanitary
Fixtures
Sealing
compound
Cut pipe
Concrete
Slab
Finishing work
(Architectural work)
PVC pipe
Process 1)
1. Install pipe and steel panel.
2. Fill concrete. Make slope
for water proofing.
3. Water proofing
( Architectural work )
Process 2)
1. Finishing work by Architectural work.
2. Cut pipe.
Process 3)
1. Install Equipment.
2. Apply sealing compound.
(Fire stopping will be supply late)
Figure 15 Detail of pipe penetration for water proof
Page 15
4.4.6.Methodologies:
-
For all sprinkler piping installation either wall or ceiling area.
-
Work will be executed by fixing anchor bolt into concrete structure or brick wall with approved
bracket support and dimension according to approved shop drawing
-
All brackets supports shall be factory-fabricated and hot dipped galvanized to JIS H8641 Standard
prior to delivery to site for installation.
-
Deliver pipes and fittings to designated area of site work. Check and ensure sufficient quantity for
area installation.
-
All supports shall be fabricated at workshop factory shall be approved type based on sample
submitted and approved by the Engineer.
-
Installed supports will be checked by the Engineer.
-
All bolt and nuts accessories shall be approved brand/ types by the Engineer based on submission
and approved.
-
Locate position of pipe installation as according to shop drawing.
-
Siamese fire department connection shall be as per approved drawing location easily be
approached by fire engines for emergency fire fitting. Type of connection shall be compatible
with hose fitting used by the local fire department and based on Vietnamese standard.
a)
-
Pipe shaft area :
Carry pipe by manual labor to location. Chain block may be used to lift bigger pipe for
installation.
b)
On ceiling area :
-
Carry pipe to designated area of installation: for bigger pipe, chain block shall be used to hoist
pipe to ceiling area.
-
Pipe shall be cleaned before installation.
-
Pipe shall be adjusted to fix location as according to approved shop drawing indicated and
according to the construction schedule.
-
Mark and determine the location of pipe support.
-
Installed pipe shall be pressure tested and inspected by the Engineer for approval.
-
Shall be cleaned system before pressure test / leak test.
4.4.7
Marking and cutting.
Page 16
-
All pipes size diameter 150mm and smaller shall be cut by electric powered, circular machine
with abrasive wheel. Metallic wheel cutters shall not be permitted.
-
For pipes with outside diameter 150mm and greater shall be cut by Oxyacetylene torch.
-
After cutting, edges of pipe shall be grinded forming an angle of 300. Refer to Figure 10
4.4.8
Cut a hole to join smaller pipe:
For steel pipe connect to steel pipe that is two times smaller than diameter of main pipe
-
Cut a hole on main pipe by using oxyacetylene torch to create a hole.
-
Use grinder machine to smoothen the edges and burrs of the cut hole before joining the main pipe
and the smaller pipe together forming a 900C
-
Seam of joining shall be welded in three passes.
-
During work not in progress, the opening of hole shall be temporary capped to prevent entry of
foreign object.
-
Take out galvanize for Fire protection
-
For flange weld, spot weld at 1 point, then connect flange surface perpendicular to pipe and spot
weld at 3-4 points prior to full welding and after that take down floor weld complete for Fire
protection pipe. Note that seam of weld in outside face shall not be out off flange face.
-
Remove water, oil and paint off completed weld.
-
Weld at 3-4 points on seam, then roll pipe to continue welding from up and down.
-
Completed weld shall be clean by using wire brush and prime paint.

Inspection of weld. Refer to Figure 10
-
Weld seam shall be checked visually.
-
Weld joint will be thicker than edge of pipe maximum 3mm.
-
Weld defects shall be remoed and repaired under the Engineer’s supervision.
a.
Screwed threaded connection.
-
Pipe will be threaded by using the threading machine JIS B0203 Standard with automatic thread
defining dimension.
-
Add suitable oil onto the cutting part or filling oil regularly onto cutting part of threading
machine. When oil changes color due to mixing with water, change new oil.
-
Change threading teeth when pitches are not threading in regular manner due to wear and tear.
-
Check length and surface of pitches visually and adjust selection of threading range by hand.
-
Remove oil and dust on pitches, inside and outside pipe prior to start threading.
Page 17
b.
Tightening threaded pipe and fitting.
-
Apply teflon sealing tape around the threaded pipe.
-
Screw pipe and fitting by hand, and then use pipe wrench to tighten slowly till pipe and fitting
firmly tighten.
-
After tighten screw connection, cover odd pitches with primer paint and mark of pipe wrench.
-
Pressure test shall be carried out after area pipe work completed and jointed area paint dry up.
d.
Sprinkler heads installation and coverage.
-
A sprinkler head shall be installed at every part of a ceiling divided by beam, etc. projected 0.4m
above from the surface of installation for the said heads. However, this shall not apply in case the
mutual central distance of the said beams does not exceed 1.8m or less.
-
In case there should be 1.2 m above of width and length for air duct, shelf etc, a sprinkler head
shall be installed at the bottom surface of the said duct etc.
-
A distance between the deflector of sprinkler heads and the surface of installation for the said
heads, shall be 0.3m below.
-
Sprinkler heads shall be so installed that the spindle thereof is perpendicular to the surface to
which the said head is fitted.
-
Nothing shall be either installed or placed in the section within the distance of 0.45 m from the
deflector of a sprinkler head, and 0.3m below of horizontal direction, or installation refer to Spec
4.4.9
Support installation
a.
For ceiling support. Refer to Section on ceiling (file Autocad)
-
Drill a hole and insert anchor bolt into concrete structure according to construction working
schedule and approved shop-drawing.
-
Fix threaded rod support into insert anchor bolt and fix C-channel into location before laying pipe
onto the bracket support.
-
Check the level of bracket support to ensure the pipe work have been done as according to the
approved shop drawings and location.
Support hanger sizes on ceiling
Page 18
b.
Supported pipe (mm)
Rod diameter (mm)
50 and smaller
08
50-100
10
125 through 200
16
250 and larger
24
For support on wall and pipe shaft. Refer to Figure Riser (file AutoCad)
- Mark sure & fabricate support and then Galvanize for level B3, B2, B1, Roof, Riser
-
Check support by plump-line to ensure bracket support are in a vertical straight line
- Fix bracket support onto wall and fastened with nuts to get support in position.
- Mark the location of pipe support as according to approved shop drawing.
4.4.10
-
Drive a hole into wall of concrete structure or brick wall.
-
Drill an anchor bolt into drilled hole.
-
Fix bracket support onto wall and fastened with nuts to get support in position.
Prime paint and identification of pipe
-
Completed pipe will be prime paint by the approved color code.
-
Symbol of identification of pipe will be suitable to diameter of pipe.
-
Direction of arrow denote the way of water flow
Schedule of lettering sizes
(or refer to spection)
Outside diameter of pipe or
covering (mm)
Size of stencil
letter (mm)
Minimum length of flow
arrow (mm)
20 to 40 incl.
50 to 100 incl.
12
25
60
100
125 to 175 incl.
50
125
200 and larger
75
150
Schedule of hanger support spacing
Page 19
Location
Pipe
Steel pipe
20mm
diameter or
less
25mm to
40mm
diameter
50mm to
80mm
diameter
100mm
diameter or
more
2.0mm
2.0mm
2.0mm
3.0mm
5 Machinery & Tools
-
Power hacksaw
-
Circular cutting machine with abrasive wheel
-
Pipe clamp
-
Plump-line
-
Power drill.
-
Chain block.
-
Threading machine.
-
Scaffolding
-
Pipe wrench
-
Spanner
-
Hammer
-
Water level ruler
6. Safety Measures
-
Temporary barricade and warning sign shall be set up at area of site work
-
Any worker works at the height of 2m and above shall wear safety belt.
-
Workers shall be trained about safety condition.
-
Machineries, equipments and staging should be inspected by safety supervisor prior to work
-
A safety forms signed by workers and briefing before work will be provided to control the safety
working condition (forms enclosed).
7. Appendix
-
Leaking test record.
-
Available for Inspection (AFI)
-
Inspection Record (IR)
8. Paniting sefety fire pipe
Step 1: Carry pipe to location area installation, properti floor at work area to be done.
Step 2: Clean pipe
Page 20
Step 3: Painting Iron-Mould safety and (Break-Zinc if need) by Grey color
Step 4: Painting one undercoat by Red color
Step 5: Painting complete safety by Red color – 1ST
Step 6: Painting complete safety by Red color – 2ND
Step 7: Check after instal finish
Page 21