LowFlow Mark 5800HP Series Back Pressure Regulator - Manual (Page 2)

3170 Wasson Road • Cincinnati, OH 45209 USA
Phone 513-533-5600 • Fax 513-871-0105
[email protected] • www.lowflowvalve.com Bulletin IM-5800HP-0411
11. Thread the lower spring guide onto the piston and
tighten securely. You will have to compress the stem
seal when tightening.
12. Place the cylinder assembly into the body with the
plug pointed towards the seat. You must be very
careful not to damage the cylinder o-ring on the
threads of the body.
13. Using pressure from your fingers, press the cylinder
assembly all the way into the counterbore. You may
have to work from side to side to get this properly
seated.
14. Install the spring and upper spring guide onto the
lower spring guide.
15. Use anti-seize and generously coat the spring hous-
ing threads.
16. Assemble the spring housing into the body and
tighten with a pipe wrench securely.
17. Lubricate all of the adjusting screw threads with
anti-seize.
18. Thread the jamnut onto the adjusting screw.
19. Slide the nametag onto the threads.
20. Thread the adjusting screw assembly into the spring
housing until you can feel the range spring start to
compress.
21. If not already done, stamp “inlet” and “outlet” on the
appropriate ports. This should be done above the
ports on the milled flats. The inlet side has a verti-
cal hole drilled into it, and the outlet has a horizontal
hole at the bottom of the port.
Final Testing
1. Verify that all the information on the nametag is correct.
2. Make sure that both the Inlet and Outlet ports are
stamped properly. (see Assembly Instructions).
3. Place the valve in the test fixture.
4. Remove all spring compression from the range
spring.
5. Apply 100 psi to the inlet and close the downstream
isolation valve. (Make sure you hear flow coming
through the valve).
6. Apply a soap solution to the entire valve and check
for leaks. Pay special attention to the bleed hole in
the spring housing. If leakage occurs here, either
the stem seal is bad, or one of the o-rings has been
damaged.
7. Open the downstream isolation valve, and apply
spring tension until the valve shuts off.
8. Close the downstream valve and check for Class VI
leakage.
9. Blow valve dry and install protectors on the end
connections.