Trapping Ahead of Steam
Regulators
When steam pressure or temperature regula-
tor valves are installed in a steam line, con-
densate may back up ahead of the valve
when it is off. When the valve opens with con-
densate backed up on the inlet side, the con-
densate will cause water hammer.
Where the branch connection to a control
valve is less than 10 ft., the branch line may
pitch toward the steam main to allow conden-
sate to flow back into main.
When the branch line is over 10 ft., pitch the
branch line toward the control valve and
install a steam trap. The steam trap should
be as close to the control valve as possible.
23
STATIC
HEAD
SHUT-OFF
VALVE
“Y” STRAINER
SHUT-OFF
VALVE
TRAP
STATIC
HEAD
SHUT-OFF
VALVE
TRAP
“Y” STRAINER
SHUT-OFF
VALVE
10' OR LESS
PITCH TOWARD STEAM
MAIN 1/2" PER FOOT
STEAM
MAIN
OVER 10'
PITCH TOWARD
STEAM MAIN
1/2" PER FOOT
STEAM
MAIN
TRAP
Installation of drip trap ahead of riser or expansion joint
Installation of drip trap in long run of steam piping or ahead of control valves
