LowFlow JRHF Series Pressure Regulating Valves - Manual (Page 3)

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repair kit into the body. The larger diaphragm plate
(6) should be on top.
11. Place the range spring (4) on top of the diaphragm
assembly, and the spring guide (5) on top of the
range spring (4).
12. Replace the spring housing (2) after coating the
threads with anti-seize. Tighten until the spring hous-
ing makes contact with the diaphragm (8). Tighten
1/4 - 1/2 turn past the contact point.
13. Replace the adjusting knob (3) by coating the
threads with anti-seize and threading it into the
spring housing and turning CW.
C. Diaphragm Replacement
Caution! To prevent damage to body, use soft jaws when
placing the body in a vise. Position so that vise closes over
the flats on lower end of body.
1. Rotate the knob (3) CCW until it comes out of the
spring housing (2).
2. Place the valve body (1) in a vise clamping on the
flats on the bottom of the body (1).
3. Remove spring housing (2) by grasping the flats with
a wrench and turning (CCW).
4. Remove the diaphragm assembly (6, 7, & 8).
5. Disassemble the diaphragm subassembly (6, 7, & 8).
6. Clean all reusable parts according to owner’s proce-
dures.
7. Inspect and replace any necessary parts. NOTE: Use
only parts manufactured and supplied by LowFlow
Valve for these products.
8. Reassemble diaphragm assembly (6, 7, & 8) by plac-
ing the diaphragm (8) and upper diaphragm plate
(6) over the threads of the lower diaphragm plate
(7). Tighten the assembly until the diaphragm (8) just
starts to deform using a screwdriver in the slot of
the lower diaphragm plate (7) and holding the upper
diaphragm plate (6) in a vise.
9. Place diaphragm subassembly (6, 7, & 8) onto the
body (1).
10. Place the range spring (4) on top of the diaphragm
assembly (6, 7, & 8). Place the spring seat (5) on top
of range spring (4).
11. Place the spring housing (2) over the spring seat (5)
and range spring (4). Screw the spring housing (2)
CW into the body (1). Tighten the spring housing (2)
until it makes contact with the diaphragm (8). Turn
1/4-1/2 turn past the contact point. Remove from
vise.
12. Replace the adjusting knob (3) into the spring hous-
ing (2) until range spring tension is felt.
13. Pressurize with air and spray liquid leak detector
around body (1) and spring housing (2) to test for
leakage. Ensure that an outlet pressure is main-
tained during this leak test of at least mid-range
spring level.
Troubleshooting
1. Erratic Operation; Chattering
A. Oversize regulator; inadequate rangeability
1. Check actuator flow conditions, re-size regulator for
minimum and maximum flow.
2. Increase flow rate.
3. Decrease regulator pressure drop; decrease inlet
pressure by placing a throttling orifice in inlet piping.
4. Install next step higher range spring. Before replac-
ing regulator, contact factory
B. Worn poppet; inadequate guiding
1. Replace trim (possible body replacement)
C. Weakened/broken return spring.
1. Determine if corrosion is causing. Replace return
spring.
2. Regulator can’t pass sufficient flow
A. Regulator not closing tightly
1. Inspect the seat of the plug sub-assembly,
replace if worn.
B. Downstream blockage
1. Check system; isolate (block flow at regulator inlet
- not outlet.
2. Relocate regulator if necessary
C. No pressure relief protection
1. Install safety relief valve, or rupture disc.
D. Restricted diaphragm movement
1. Ensure no moisture in spring housing at tempera-
ture below free point.