Appendix e, Hydro-pneumatic tank field installation – Bell & Gossett S14141B 70X Multiple Pump Pressure Booster Systems User Manual

Page 12

APPENDIX E

HYDRO-PNEUMATIC TANK FIELD INSTALLATION

Figure 3

5.0 PRV Does Not Close (Check) on

Pump Shut Down

5.1

Primary Causes
a) Insufficient pressure on top of diaphragm.
b) Leak through main valve seat or diaphragm
assembly.

5.2

Remedies (see Figure 2 for item numbers)
a) Stop cock (Item 7) closed preventing pressure

from reaching valve cover.

b) Leaking check valve (Item 2).
c) To determine whether leak is in main valve seat

or diaphragm assembly:
1. Disconnect line between flow control valve

(Item 4) and valve cover.

2. Plug flow control side.
3. Install pressure gauge in valve cover.
4. Remove vent plug in pump volute to drain

inlet side of PRV.

5. Apply pressure to top side of diaphragm by

opening shutoff valve on outlet side of PRV.

6. Read gauge pressure.
7. Close stop cock (Item 7).

If gauge pressure fails, there is a leak in the dia-
phragm assembly. This test, however, does not
indicate whether the seat is also leaking.

6.0 PRV Slams Shut on Pump Shut Down

6.1

Primary Causes
a) Too rapid buildup of pressure on top of

diaphragm.

b) Main valve assembly binding.
c) Check valve (Item 2) sticking open momentarily

6.2

Remedies (see Figure 2 for item numbers)
a) Throttle stop cock (Item 7).

NOTE: Closing this stop cock will completely
prevent PRV from functioning as a check valve.

b) Vent air from PRV (see 1.2b).

Xylem Inc.

10661 Newkirk Street

Dallas, TX 75220

Phone: (469) 221-1200

Fax: (214) 357-5861

www.xyleminc.com/brands/bellgossett