3. Inspection
All KESSEL backwater valves should be inspected
once a month by the operator or by a representa-
tive of the operator.
4. Maintenance
4.1 Cleaning of the single flap lockable
backwater valve and single flap backwater
valve every six months
The single flap lockable backwater valve and sin-
gle flap backwater valve should be cleaned by the
operator or a representative of the operator at
least every six months. The procedure is as fol-
lows:
Remove the cover
Remove the insert(s) and / or the flap
Clean all parts
Check seals and sealing surfaces (and fit
new ones if required. Use KESSEL original
parts.)
Apply grease to the outside of the seals for
the insert and to the guide for the flap valves
Reinsert housings accurately
Replace and tighten the cover
14
GB
On both lockable backwater valves the emergen-
cy flap should be checked by opening and closing
it several times.
4.2 Servicing of the double flap lockable
backwater valve every six months by a spe-
cialist
According to EN 13564 industrial standard,
backwater valves must be serviced by a speci-
alist at least every six months.
No sewage should be allowed into the backwater
valve during servicing.
The servicing work to be carried out includes the
following operational check:
Remove the cover
Fill the opening between the two flaps with
water
Replace and tighten the cover
Remove 1/2" screw plug from the cover and
screw in funnel
Move the lever and emergency flap on the
cover to the „CLOSED" position
Once the inspection is complete, be sure to leave
the manual locking lever in the „open" position.
Fill the funnel with water to a depth of
100 mm
Observe the depth of water in the funnel for
10 minutes and top it up to maintain the level
if required.
The backwater valve is considered to be
watertight if no more than 500 cm
ter has to be added during this time
Remove funnel. Screw the screw plug with seal
back into the cover
Replace and tighten the cover
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