3
1. Connect a steam line (A) from the steam supply to the
area where regulator valve is to be located. Install tee
fittings (B) for a bypass line, and (C) for the regulator
line.
Note: Drip traps prevent condensate from collecting in
the piping during light loads or when the regulator is
closed. Collected condensate in the piping ahead of
the regulator can cause water hammer when the
regulator opens.
2. Install a shut off valve (E) to allow servicing the trap.
3. Provide a dirt pocket ahead of the strainer to allow
large solids to drop out.
4. Install a drip trap (H), Y-strainer (F) equipped with a
screen and blow down valve (G).
5. Cap the blow down valve outlet to prevent steam
discharge due to accidental opening of valve.
6. Connect a horizontal pipe from tee (C).
7. Connect a reducer (D), if required, to reduce the
steam line to the pipe size of the main valve.
Use additional reducers when the pipe needs to be
reduced more than two pipe sizes. When noise is a
concern, reducers should not have more than a 15
degree taper.
8. Install shut off valve (J) and Y- strainer (K). Turn the
strainer so that the screen is horizontal to prevent
condensate from collecting in the screen pocket.
Condensate pockets can carry with the steam flow,
causing water hammer that can destroy the main
valve diaphragms.
9. Install a strainer blow down valve (L).
10. Cap the blow down valve outlet to prevent steam
discharge due to accidental opening of valve.
11. Install tee, siphon loop tube, petcock, and pressure
gauge.
12. On
NPT sized regulator valves,
install a pipe union (M)
to allow regulator removal for service or replacement.
13. Use compressed air or steam to clean piping before
installing the regulator.
• Cap off the end of the steam line.
• Remove caps from the strainer blow down
valves (G) and (L).
• Turn on the steam or air to full pressure and allow
it to blow down for five minutes.
• Close off compressed air or steam.
• Allow piping to cool below 100˚F.
• Reinstall end of line caps on blow down valves.
• Remove cap from end of the steam line.
14. Install main valve (N) with the direction arrow pointing
to the low-pressure side outlet piping.
NPT sized regulator valves:
• Use pipe sealant on male threads only, keeping the
sealant out of the system.
• Use a wrench on the flats of the body to tighten
the joint.
• Use the wrench on the side of the body that is being
tightened to prevent stress and distortion on the body.
Flanged regulator valves:
• Inspect flange surfaces and gaskets.
• Tighten flange bolts using a star pattern. Uneven
bolting may cause steam leakage.
15. Install silencer orifice plate (when used) immediately
after the main valve:
NPT sized regulator valves:
Install orifice plate
between two ASME flanges.
Flanged regulator valves:
Install the orifice plate
between the valve flange and the outlet pipe flange.
16. On
NPT sized regulator valves,
install a pipe union (O)
to allow regulator removal for service or replacement.
17. Install gate valve (P).
18. Install pipe tee (R) for bypass connection.
N
10 Pipe
Diameters
O
M
H
F
G
E
J
L
P
R
S
Z
Y
X
W
U
V
T
B
A
C
K
D
INSTALLATION DETAIL
Main Valve Installation
