LowFlow JRHF Series Pressure Regulating Valves - Manual (Page 2)

downstream system without changing the following
steps.
2. Relax the range spring by turning the adjusting knob
(3) counter clockwise (CCW) until there is no notice-
able spring tension.
3. If it is a “hot” piping system, and equipped with a
bypass valve, slowly open the bypass valve to pre-
heat the system piping and to allow slow expansion
of the piping. Closely monitor outlet (downstream)
pressure via gauge to ensure no over-pressurizing.
Note: if no bypass valve is installed, extra caution
should be used in starting up a cold system; i.e. do
everything slowly.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve observ-
ing the outlet (downstream) pressure gauge. Deter-
mine if the regulator is flowing. If not, slowly rotate
the regulator adjusting knob (3) clockwise (CW) until
flow begins.
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
7. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream piping
isn’t pressurized. If the outlet (downstream) pressure
exceeds the desired pressure, close the block valve
and go to Step 2, then return to Step 4.
8. When flow is established steady enough that the
outlet (downstream) block is fully open, begin to
slowly close the bypass valve if installed.
9. Develop system flow to a level near its expected
normal rate, and reset the regulator set point by
turning the adjusting knob (3) CW to increase outlet
pressure, or CCW to reduce outlet pressure.
10. Reduce system flow to a minimum level and observe
set point. Outlet pressure will rise from the set point
of Step 9.
Shutdown
1. On systems with a bypass valve, and where system
pressure is to be maintained as the regulator is shut-
down, slowly open the bypass valve while closing
the inlet (upstream) block valve. (When on bypass,
the system pressure must be constantly observed
and manually regulated.) Close the outlet (down-
stream) block valve. CAUTION! Do not walk away
and leave a bypassed regulator unattended.
2. If the regulator and system are to both be shut
down, slowly close the inlet (upstream) block valve.
Close the outlet (downstream) valve only if regulator
removal is required.
Maintenance
Warning! System Under Pressure. Prior to performing
any maintenance, isolate the regulator from the system
and relieve all pressure. Failure to do so could result in
personal injury.
A. General
1. Maintenance procedures hereinafter are based
upon removal of the regulator unit from the pipeline
where installed.
2. Owner should refer to owner’s procedures for
removal, handling, cleaning and disposal of non-
reuseable parts, i.e. gaskets, etc.
3. Refer to the basic regulator and Figure 2 for dia-
phragm subassembly.
B. Trim Replacement
Note: One of the features designed into the JRHF
valves is that a complete trim replacement and wet side
cleaning can be done with the valve still installed with-
out complete disassembly. But please note the warning
above. Make sure all upstream and downstream valves
are closed and all pressure is relieved prior to doing
work. Use only parts supplied in a LowFlow Valve Repair
Kit.
1. Remove adjusting knob (3) by turning CCW until the
threaded portion comes out of the spring housing
(2).
2. If valve is removed from the line, place it in a vice,
spring housing up.
3. Remove the spring housing (2), the upper spring
guide (5), range spring (4), and diaphragm assembly
(6, 7, & 8).
4. Remove the diffuser (9), diffuser gasket (12), and soft
seat (10).
5. Remove the plug (11) and the return spring (13).
6. Remove the old o-ring (14) from the plug (11) and
replace it with a new one. Lubricate with anti-seize.
7. Place the new return spring (13) into the body (1),
followed by the plug (11).
8. Place the new soft seat (10) into the main body bore.
9. Place the new diffuser gasket (12) onto the diffuser
(9). Coat the threads of the diffuser (9) with an anti-
seize compound and thread into the body hand
tight. Using a socket wrench, tighten the diffuser (9)
1/4 turn past hand tight, taking care not to scratch
the body (1).
10. Place the new diaphragm assembly (6, 7, & 8) from
-2-
Figure 2. Diaphragm Subassembly