Cla-Val 7100 Technical Manual - Manual (Page 6)

Hammers while opening
and continues to pul-
sate while flowing.
Fails to Close
Closes but fails to
hold drip tight
Fails to Open
Insufficient Pressure to Cover
Chamber
Damaged Diaphragm
Mechanical Obstruction
Worn disc or scarred seat
Insufficient line pressure
Pilot Control System not draining
to atmosphere
Low flow condition with fall of
pipe at valve outlet creating neg-
ative pressure at valve outlet
Check Pilot Control System Pressure. In order for
valve to close, pressure to valve cover chamber must be
equal to, or greater than, pressure at valve inlet.
The following method will determine if there is a damaged
diaphragm without removing the valve cover: Put pressure into the
valve and disconnect control tube from valve cover chamber. If there
is continuous flow through the tube connector fitting, the diaphragm
is damaged, or the diaphragm assembly on the stem bolt is loose.
Remove valve cover, and diaphragm-disc assembly. Check
for foreign objects in valve seat or imbedded in valve disc.
Check as above, and replace disc or seat if necessary.
Minimum requirement with cover chamber vented to
atmosphere, 7-10 psi (7100KH).
With line pressure in valve, disconnect control tube from valve
cover chamber. Valve should open. Check for obstruction in con-
trol tube, pilot valve and pilot valve drain to atmosphere
At top of pipe fall, install air vent to break vacuum. A small
spring loaded ball check may be installed in downstream body
tapping of valve.
SYMPTOM PROBABLE CAUSE PROCEDURE
SERVICE SUGGESTIONS
CLA - VAL
copyright Cla-Val 2003 Printed in USA Specifications subject to change without notice.
P.O. Box 1325 • Newport Beach, CA 92659-0325 • Phone: 949-722-4800 • Fax: 949-548-5441 • E-mail: [email protected] • Website cla-val.com
©
N-7100 (R-9/03)
Item Description Qty.
No.
1. Body 1
2. Cover 1
3. Seat 1
4. Disc 1
5. Guide, Disc 1
6. Retainer Disc 1
7. Diaphragm 1
8. Washer, Diaphragm1
9. Bolt, Stem 1
10. Nut, Hex 1
11. Spring 1
12. Bolt Hex Hd. 4
13. O-Ring 1
14. Plug, Pipe 1
15. Plug, Pipe 1
16. O-Ring 1
17. Screw Drive 2
18. Washer, Bellville 1
19. Washers 1
20. Nameplate 1
Parts List
15
14
2
11
7
3
13
1
12
20
17
9
18
19
6
4
5
16
8