172-65174MA-11 (COSR Pressure Reducing Valve) 16 Feb 2022
18
Disassembly
Use hoisting equipment for heavy objects (weighing approximately
20 kg or more). Failure to do so may result in back strain or other injury if
the object should fall.
CAUTION
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 COSR 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 COSR
completely. Relieve residual steam
pressure by slightly loosening the spring housing bolt and pilot screen holder or plug
on the sensing line port. Wait for the body to cool before attempting to remove the
COSR
from the line. Then remove inlet and outlet flange retaining bolts and nuts to
permit removal of the COSR. Secure the COSR
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 guide.
Check for seizure or any damaged screw threads.
15 to 150 mm (
1
/
2
to 6 in)
Spanner Cap
Nameplate
Adjustment Screw
Ball
Spring Retainer
Coil Spring
Diaphragm Support
Hex Bolt
Spring Housing
Locknut
