SECTION VI
UL EX-4510 7-15-02 Page 6-7
REV. 1
Installation
INSTALLING DISTRIBUTION PIPING (Continued)
General Piping Requirements
NOTE: Actual grades and sizes will depend on maxi-
mum downstream pressure from the flow calcu-
lation.
1. All threaded pipe beyond the pressure reducer, or
selector valve, if applicable, to be black iron or galva-
nized of the following pipe size and grade combina-
tions.
ASTM A-106, Sch. 40-through 8 in.
Seamless, Grade C
ASTM A-106/A-53 Sch. 40-through 5 in.
Seamless, Grade B
ASTM A-106/A-53 Sch. 40-through 2.5 in.
Seamless, Grade A
ASTM A-53 ERW, Grade B Sch. 40-through 3 in.
ASTM A-53 ERW, Grade A Sch. 40-through 1.25 in.
2. All threaded pipe used to construct the manifold,
including pipe before the pressure reducer, to be black
iron or galvanized of the following pipe size and grade
combinations.
ASTM A-106 Sch. 80-through 1.25 in.
Seamless, Grade C
ASTM A-106/A-53 Sch. 80-through 1 in.
Seamless, Grade B
ASTM A-106/A-53 Sch. 80-through .5 in.
Seamless, Grade A
ASTM A-53 ERW, Grade B Sch. 80-through .5 in.
ASTM A-53 ERW, Grade A Sch. 80-through .38 in.
ASTM A-106 Sch. 160-through 8 in.
Seamless, Grade C
ASTM A-106/A-53 Sch. 160-through 8 in.
Seamless, Grade B
ASTM A-106/A-53 Sch. 160-through 2 in.
Seamless, Grade A
ASTM A-53 ERW, Grade B Sch. 160-through 4 in.
ASTM A-53 ERW, Grade A Sch. 160-through 1 in.
3. All fittings beyond the pressure reducer to be 300 lb.
(or higher depending on maximum downstream pres-
sure) ANSI B-16.3 black malleable iron or galvanized
threaded fittings through 3 in. size. Forged steel fittings
to be used for larger sizes. All flanged joints to be
Class 600 lb. (Class 300 malleable iron unions or
street elbows shall not be used.)
4. All fittings used to construct the manifold, including fit-
tings before the pressure reducer, to be black iron or
galvanized 2000 or 3000 lb. class ANSI B-16.11.
5. A120 pipe SHALL NOT BE USED.
6. Cylinder and piping to be securely bracketed – espe-
cially at the fittings and nozzles.
7. Ream, clean, and blow out all pipe before installing.
8. All dead end pipe lines to be provided with a capped
nipple, 2 in. long. See Figure 7.
FIGURE 7
001876
9. All pipe lengths are measured center to center of fit-
tings.
10. All distribution pipe and fittings must be assembled
using either pipe tape or pipe dope. Do not add to the
first two threads nearest the end of the pipe.
11. Install pressure reducer/union in the piping with the
orifice identification tab on the pressure inlet side of
the system. The 1 1/4 in., 1 1/2 in., and 2 in. pressure
reducer/union must be installed per the direction of the
flow arrow stamped on the body.
12. Critical length from pressure reducer to first tee must
be a minimum of 10 nominal pipe diameter.
13. Refer to “Pipe Pressure Rating Chart,” Pages 5-23 –
5-25, in Design section for selection of the correct
pressure rated pipe.
14. Size reductions can be accomplished with the use of
reducing bushings, reducing couplings, reducing tees,
or reducing elbows.
15. Bushing up (increasing pipe size) in the downstream
piping is acceptable immediately after the pressure
reducer only. Increase in size can be no greater than
two nominal pipe sizes. Only the use of a close nipple
and reducing coupling or a swaged nipple can be used.
16. Pressure reducer must be the same size as the
system manifold outlet pipe size.
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