4
Customer Service
(704) 841-6000
www
.apolloflowcontrols.com
“Apollo”
Flow Controls
INSTALLATION, OPERATION & MAINTENANCE
MANUAL
III. TROUBLESHOOTING
SYMPTOM
CAUSE
CORRECTIVE ACTION
Relief valve continuously discharges during
no-flow condition.
1. #1 check valve fouled with debris.
2. #2 check valve fouled with debris
coupled with a back-pressure condition.
3. #1 check poppet stem not moving freely
in guide (or #2 check poppet during a
back-pressure condition
1. Inspect and clean seat disc and seat
2. Inspect and clean seat disc and seat.
3. Inspect for debris or deposit on poppet
stem or guide.
Relief valve discharges continuously during
flow and no-flow conditions.
1. Relief valve fouled with debris.
2. Damaged diaphragm (allows water to
pass through from inlet to zone).
3. Sensing passage to inlet side of
diaphragm plugged.
4. #1 check poppet stem not moving freely
in poppet guide.
5. 1st and 2nd check springs are in
wrong check.
1. Inspect and clean relief valve seat disc
and seat.
2. Replace diaphragm.
3. Inspect and clean passage in cover and
body.
4. Inspect for debris or deposits on poppet
stem or guide.
5. Switch springs to proper check location.
Relief valve discharges intermittently in a
“spitting” action during no-flow condition.
1. Pressure fluctuations or water hammer
from supply.
1. Eliminate or reduce supply pressure
fluctuations.
Relief valve does not open during test No. 1.
2. #2 shut-off valve not closed completely.
3. Test equipment improperly installed.
4. Plugged sensing line.
1. Close #2 shut-off valve or inspect for
possible through leakage.
2. Recheck test procedure.
3. Clean sensing line.
#2 check valve fails to hold back-pressure.
1. #2 shut-off valve not closed completely.
2. #2 check valve fouled with debris.
3. #2 check poppet stem not moving freely
in guide.
1. Close #2 shut-off valve or inspect for
possible through leakage.
2. Inspect and clean seat disc and seat.
3. Inspect for debris or deposits on poppet
stem or guide.
Pressure differential across #1 check valve is
low during field test No. 3 (does not meet 5
PSID minimum).
1. #1 check valve fouled with debris.
2. Upstream pressure fluctuations causing
inaccurate gauge reading.
3. #1 check poppet stem not moving freely
in guide.
1. Inspect and clean seat disc and seat.
2. Eliminate pressure fluctuations.
3. Inspect for debris or deposits on poppet
stem or guide.