172-65260m-05 (S-COS/S-COSR Pressure Reducing Valve) 27 Oct 2008
15
Disassembly
NEVER apply direct heat to the float. The float may explode due to
increased internal pressure, causing accidents leading to serious injury
or damage to property and equipment.
WARNING
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
It is a recommended practice to dismantle and inspect the pressure reducing valve
once a year for preventive maintenance purposes. It is especially important to
perform an inspection immediately after the initial run of a new line or before or after
equipment such as a heater is out of service for a long period of time. (Installation,
inspection, maintenance, repairs, disassembly, adjustment and valve opening/closing
should be carried out only by trained maintenance personnel.)
Remove all steam from the piping (both upstream and downstream). If the steam
supply to the system cannot be shut off, change over to bypass operation. Close
shut-off valves at the inlet and outlet of the pressure reducing valve completely.
Relieve residual steam pressure by loosening slightly the spring housing bolt and
screen holder or plug. Wait for the body to cool before attempting to remove the
pressure reducing valve from the line. Then remove inlet and outlet flange retaining
bolts and nuts to permit removal of the pressure reducing valve. Secure the pressure
reducing valve in a vise to perform the inspection.
Disassembling the Adjustment Section
Loosen the adjustment screw completely and remove the bolts. Having removed the
spring housing, you will see the diaphragm support, coil spring and spring retainer.
Check for seizure or any damaged screw threads.
Nameplate
Adjustment Screw
Locknut
Spring
Housing
Bolt
Coil Spring
Diaphragm Support
Spring Guide
Ball