172-65175MA-13 (COS Pressure Reducing Valve) 16 Feb 2022
15
Adjustment
The COS reducing valve should be properly adjusted for protection of the steam-
using equipment against water hammer.
1. It is necessary to blow down all pipe lines thoroughly. The blowdown is especially
important if the line is new or has been shut down for a long period of time.
Take particular care to ensure that matter such as condensate and dirt does not
remain inside the steam-using equipment.
(Stay clear of any pressurized blow-out from the safety valve.)
2. Make sure that the shut-off valve and the bypass valve located upstream and
downstream of the COS are completely closed.
3. Remove the spanner cap, loosen the locknut and turn the adjustment screw
counterclockwise to reduce tension on the coil spring.
4. Slowly, fully open the shut-off valve at the inlet of the COS. Allow sufficient time
for condensate remaining at the inlet of the COS to be discharged.
5. Slightly open the shut-off valve at the outlet of the COS.
6. Turn the adjustment screw until the desired outlet pressure is obtained. Wait
several minutes.
7. Slowly, fully open the shut-off valve at the outlet of the COS.
8. After setup, retighten the locknut and replace the spanner cap.
9. When shutting down the system, always close the outlet shut-off valve first and
then the inlet valve.
Loosen the locknut
Loosen the adjustment screw
Counterclockwise
Clockwise
Counterclockwise
Loosen the Adjustment Screw
Decrease Pressure
Tighten the Adjustment Screw
Increase Pressure