Cla-Val 34WW Series - Manual

CLA
-
VAL
© copyright Cla-Val 2003 Printed in USA Specifications subject to change without notice.
P.O. Box 1325 ¥ Newport Beach, CA 92659-0325 ¥ Phone: 949-722-4800 ¥ Fax: 949-548-5441 ¥ E-mail: [email protected] ¥ Website cla-val.com
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Air V
alves
CLA-VAL
WASTE WATER AIR VALVES
WITH BACKWASH ACCESSORIES
OPERATION
AND
MAINTENANCE
INSTRUCTIONS
OM 34-35WW
Date 2/99
INSTALLATION
Waste Water Air Valves with attachments for backflushing should be installed as shown on
engineers plans.
The air valve is supplied with shut-off valves for isolating the air valve from the main for
inspection and backflushing.
The valve vault should have adequate drainage and be sufficiently protected from possible
freezing conditions. Where freezing conditions exist, the air valve should be insulated (par-
ticularly on a bridge crossing) or wrapped with electrical heat tape. It is recommended the
air valve discharge ports piped to the drain; when installed inside a pump station or are to
prevent flooding should a malfunction occur. Backflush attachments include three (3) quick
disconnects, one (1) five foot length of hose with adapters and three (3) shut off valves for
flushing.
AIR VALVE OPERATION
1.
Wastewater Air Release Valves vent small pockets of air from the force main auto-
matically and close on liquid level rise. This valve is designed to open under pressure.
2. Wastewater Air & Vacuum Valves vent large volumes of air when initially filling the line,
and will close automatically with liquid level rise. As long as the line is under pressure,
the valve will not open. Under vacuum conditions, the double float will drop, allowing
air to re-enter the line, which prevents collapse of the pipeline, and damage due to
water column separation within long downward slopes. This valve will close again, only
when the line is refilled.
3. Combination Wastewater Air Valves perform both of the above functions
MAINTENANCE
To arrive at a reasonable schedule of preventive maintenance, wastewater Air valves
should be backflushed six months after start-up date (not installation date). During this first
backflushing, the operating engineer should observe the time and severity of waste that is
flushed out of the air valve body. If clean flushing results in a few minutes the next period
for backflushing can be set at twelve (12) months. If clean flushing is difficult and exceeds
fifteen (15) minutes, the next backflushing should be scheduled in (4) months. A log should
be kept and the valve tagged with latest flushing. Backflushing should be done at least once
a year to insure efficient operation of the air valve. Otherwise grease and scum build up
inside the body may prevent the air valve operating to release air and gas pockets.
1.
2.
3.