©COMEV
AL
V
AL
VE SYSTEMS
Technical Dept. Ref. IOM - PIST
ON (LIFT
DISC) CHECK V
AL
VES, UNIFLOW® 3P-35 - Ed.18/02
Comeval V
alve Systems reserves the right to alter any technical data contained in this Manual without prior notice. Regularly updated data on www
.comeval.es
IOM - PISTON (LIFT DISC) CHECK VALVES, UNIFLOW® 3P-35
Page 5
ATTENTION!
- The filling, warming-up and starting-up of the system shall be gradual so as to avoid any inadmissible stress. Check
for tightness in valve connections and body/cover union, and retighten crosswise and gradually if necessary until
leakage elimination. If leakage persists surfaces should be thoroughly cleaned and new gaskets correctly placed.
- Ensure valve surface is in good condition and retouch coating protection if any when needed.
- In case of risk of media freezing inside the valve, take due measures to avoid it.
7. CARE AND MAINTENANCE
The operator must define maintenance and maintenance-intervals to meet requirements.
- Check for body, seat and connections tightness.
ATTENTION!
- Before disassembling the valve, note chapters 3, 10 & 12.
- There is a crushing hazard between the disc and seat. Ensure the disc is in rest position in case a hand is intro-
duced inside the valve.
- Only carry out maintenance work in the pipework when the valve has been secured from operation.
- Check the valve surface inside and outside and retouch coating protection if any when needed. If advanced
corrosion or erosion is observed, double check service and valve features and replace the valve properly.
- In case of body/cover leakage, dismount the cover, remove old gasket, clean sealing surfaces and use a new gasket.
- In case of seat leakage, remove the valve cover to clean the seating surfaces or grind them if necessary. Discard
any jamming on the disc movement. When mounting the cover again use always new gasket, and tighten the cover
bolts evenly crosswise with moderate and uniform torque. Retighten them if leakage is detected under pressure.
- If it is not possible to repair the damages replace the valve and contact us for assistance.
After any maintenance work please refer to chapters 5 and 6 for installation / commissioning.
Recommended Spare parts:
Use only original spare parts.
It is advisable to keep body/cover gaskets as spare parts. Type and number of each spare part to be stored according to
many factors: service level, valves quantity, etc. In many cases a good choice is to keep complete valves as spare part.
8. TROUBLESHOOTING
In the event of malfunction or faulty operating performance, check that the installation and adjustment work has been ca
-
rried out and completed in accordance with this Manual.
ATTENTION!
- It is essential that the safety regulations are observed when identifying faults.
9. TROUBLESHOOTING TABLE
ATTENTION!
- Read the complete Manual before carrying out installation and repair work.
- Read chapter 6 before recommissioning
.
FAULT
POSSIBLE CAUSE
CORRECTING MEASURES
No flow
Not enough flow
Flange covers or protection not removed Clear valve entrances
Improper installation position
Follow the arrow in the body
Piping clogged
Check piping system
Not enough pressure or flow
Check working parameters
Plug guiding system blocked
Check and try to unblock
Broken flange
Bolts not properly tightened
Re-align piping and fit new valve
Mating flanges not properly aligned
Valve not closing with reverse flow
Improper installation position
Check installation position
Disc surface or seat damaged
Check valve components
Low pressure
Check the system
Broken spring
Replace the spring
Plug guiding system blocked
Check and try to unblock
Disc stick
Fine vacuum service
Use a degassing connection
Leakeage between body and cover Cover bolts loose or gasket damaged
Retighten or change gasket
Technical support always available through our website www.comeval.es or your local distributor.
