CSA air valve Mod. SCF
6
Maintenance
The combination wastewater air valve SCF is automatic in operation and requires very little
maintenance. It should always be installed in a vertical position with a maximum tilt within 4°.
A semi-annual visual inspection for leakage is recommended as well as a check of the O-rings on
the seat (ref picture on page 7). A malfunction of the air valve can be identified by the seepage of
water through the main seat and through the nozzle. Should a malfunction occur, the following steps
should be taken to repair the valve;
Disassembly Procedure
See Figures 1 on page 6 for part identification.
1. Relieve pipeline pressure or shut off isolation valve before servicing the Air Valve.
2. Slowly remove the drain port (18) to relieve internal pressure
3. Remove nuts (16), cap (3), nuts and washers (19 and 17) and extract the seat (14)
4. Inspect the sealing surface of the seat and check whether gaskets (12) and (13) are torn or
damaged
5. Remove nuts and washers (21 and 22) and pull up the upper part (2)
6. Pushing from beneath the float (4) rise it and inspect the obturator flat (11) for possible dirt and
torn out surfaces
7. The air release system (9 and 10) is placed between the end of the shaft and the obturator.
Normally it doesn’t have to be maintained and kept as a separate spare part. Simply unscrew the
obturator (11) keeping the float shaft (5) firmly secured from the hexagonal part (not holding it by
the float)
8. Inspect and clean the surface and opening of the air release nozzle (10) and clean it by means
of water or, compressed air. Be careful not to lose the O-ring between it and the obturator (11)
assuring the water tightness
9. When handling the float and its shaft (4 and 5) be aware not to bend it or deform, also check the
float surface, shape, and make sure not sign of wear, corrosion and buckling are present (possibly
due to water hammer events)
10. Be sure to leave the plane gasket between the gasket holder and the upper part in DI
11. Check the proper movement of the float, pushing it up and down through the guide (7) and make
sure no sign of friction or obstacles are present
12. The float is also guided by 4 ribs present in the lower body (1)
13. Inspect all connections of linkage for excessive wear.
14. Clean all surfaces before re-assembly.
Servicing the Air/Vacuum Valve while the pipeline is under pressure can cause personal injury or
equipment damage. Relieve pipeline pressure or shut off isolation valve before servicing the
Air/Vacuum Valve.
Do not completely remove pipe plug or cover screws while the valve is under pressure.
