Trouble Shooting. Febco LF850U-QT 1 1/2, LF850U-QT 1 1/4, 850-QT 3/4, 850 Small, LF850 Small, 850 Small, 850-QT 1 1/4, 850-QT 1/2, 850-QT 2, LF850U-QT 1/2, 850U-QT 1 1/2

TROUBLE SHOOTING GUIDE

Symptom # 1

Check fails to hold 1.0 PSID min.

Cause:

A. Debris on sealing surfaces

B. Leaking shut-off valve

C. Damaged seat or seat disc

D. Spring stem not moving freely

Solution:

Inspect and clean

Inspect and clean, or repair

Disassemble and replace

Inspect for debris or damage

Symptom # 2

Chatter during flow conditions.

Cause:

A. Worn or damaged parts

Symptom # 3

Low flows passing through the mainline valve.

Cause:

A. Mainline check fouled

Solution:

Inspect and replace

Solution:

Inspect and clean, or repair

CHECK MODULE DISASSEMBLY

1. Slowly close inlet and outlet ball valves. Bleed residual pressure by opening # 2, # 3, and # 4 test cocks. Allow the test cocks to remain open until the reassembling is completed. Test cock # 1 should remain closed.

2. Remove the cover bolts (item 21) using the appropriate size wrench.

3. Remove spacer (item 8) by grasping the flanged end of the spacer and pulling straight up.

5. Remove the outlet check assembly by placing the tip of a medium size flat nose screw driver in the slot of the seat (item 3) and prying the check assembly back until the red o-ring (item 3.1) is exposed. Then, using your fingers, pull it out from the body bore until it is completely exposed then lift out of the body.

4. Remove the inlet check assembly by pulling it in the direction of flow out from the body bore until it is completely exposed then lift out of the body.

Page 4 FEBCO Model 850 / 850U ( 1 /

2

" - 2")