2
CASH VALVE TYPE FRM-2 CRYOGENIC BACK PRESSURE OR ECONOMIZER VALVE
INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
OPERATION INSTRUCTIONS
Adjusting the Back Pressure
The regulator's back pressure setting is
adjusted by turning the adjusting screw (1) at
the top of the spring chamber after loosening
the adjusting screw lock nut (2). To obtain a
higher pressure setting, turn the adjusting
screw clockwise (into the spring chamber). To
lower the pressure setting, turn the adjusting
screw counter-clockwise (out of the spring
chamber). Tighten the adjusting screw lock nut
after the adjustment has been made and install
the closing cap.
MAINTENANCE INSTRUCTIONS
The following procedures are provided for
servicing the Type FRM-2 back pressure relief
valve. Repair parts can easily be installed
without removing the valve from the line.
CAUTION
Before attempting to replace any spare parts, be
sure to shut off all pressure connections to the
valve. With the valves closed, however, system
pressure could still be locked between the shut
off valve and the inlet and/or outlet sides of the
relief valve. Before proceeding with any valve
service, be certain to relieve the pressure from
BOTH sides of the valve.
Refer to the valve exploded view for
parts identification.
Servicing the Pressure Spring (5),
Diaphragms (10), Seat Disk (13), and
Seat Ring (14)
1. Loosen the lock nut (2) ¼ turn and turn
the adjusting screw (1) counter-clockwise
until the pressure spring (5) is no longer
under tension.
NOTE
When installing the adjusting screw during
reassembly, turn the screw clockwise untl the lock nut
just touches the spring chamber. When the valve is
placed in service, the pressure setting should be very
close to the original setting.
2. Unscrew the spring chamber (3) from the
valve body (15). During reassembly, tighten
the spring chamber securely.
3.
Remove the spring seat (4), pressure spring (5),
and the diaphragm stop (6) from the
valve body.
4. The Diaphragm assembly, consisting
of the pressure plate nut (7),
lock washer (8), diaphragm pressure
plate (9), diaphragms (10), seat disk
gasket (12) and seat disk (13), can now
be lifted off the body (15). Disassemble
the parts by unscrewing the pressure
plate nut (7) from the seat disk (13).
Inspect all parts and replace if necessary.
The diaphragm gasket (11), below the
diaphragm, should be replaced when new
diaphragms (10) are installed.
IMPORTANT
Excercise care to ensure that the surface of
the seat disk (13) is not scratched, marred or
damaged during disassembly and reassembly.
5. Once the diaphragm assembly has been
removed, the seat ring (14), which is sitting
loosely in a recess of the valve body, can
be removed.
IMPORTANT
Handle the seat ring carefully to avoid damage
to the seat ring surface which contacts the
seat disk (13).
NOTE
Be sure to install the seat disk, with the machined
groove around the outer edge of the flat face, so that
this face is up (away from the body).
6. Inspect all parts and replace if necessary.
Reassemble in reverse order. After placing
the valve back in service, adjust the
delivery pressure setting as detailed under
Operation Instructions.
REPAIR PARTS INFORMATION
Refer to the Type FRM-2 exploded view for
parts identification.
SPECIFICATIONS
Each Type FRM-2 back pressure valve is
supplied with a pressure spring selected to
provide the desired pressure setting. The range
of adjustment or satisfactory "working range"
of individual springs is shown below for each
valve size. Each valve has the "set" pressure
and range of adjustment stamped on a tag
fastened to the valve.
LIST OF MATERIALS
Item No. Description
1Adjusting Screw
2Lock Nut
3Spring Chamber
4Spring Seat
5Pressure Spring
6Diaphragm Stop
7Pressure Plate Nut
8Lock Washer
9Pressure Plate
10 Diaphragm
11 Diaphragm Gasket
12 Seat Disk Gasket
13 Seat Disk
14 Seat Ring
15 Body
