Gorman-Rupp Pumps 12B20-B 1340494 and up User Manual
Page 13
OM-00588
10 SERIES
PAGE B - 6
INSTALLATION
Except in certain specific applications (to
prevent flooding during service of an auto
matic air release valve in a below‐ground
lift station), if a manual shut‐off valve is in
stalled anywhere in a bypass line, it must
be a full‐opening, ball‐type valve to pre
vent plugging by solids.
A manual shut‐off valve should not be
installed in any bypass line. A manual
shut‐off valve may inadvertently be left
closed during operation. A pump which
has lost prime may continue to operate
without reaching prime, causing dan
gerous overheating and possible explo
sive rupture of the pump casing. Per
sonnel could be severely injured.
Allow an over‐heated pump to cool be
fore servicing. Do not remove plates,
covers, gauges, or fittings from an over‐
heated pump. Liquid within the pump
can reach boiling temperatures, and va
por pressure within the pump can cause
parts being disengaged to be ejected
with great force. After the pump cools,
drain the liquid from the pump by re
moving the casing drain plug. Use cau
tion when removing the plug to prevent
injury to personnel from hot liquid.
AUTOMATIC AIR RELEASE VALVE
When properly installed, a Gorman‐Rupp Auto
matic Air Release Valve will permit air to escape
through the bypass line and then close automati
cally when the pump is fully primed and pumping
at full capacity.
Some leakage (1 to 5 gallons [3.8 to 19
liters] per minute) will occur when the
valve is fully closed. Be sure the bypass
line is directed back to the wet well or
tank to prevent hazardous spills.
Consult the manual accompanying the Air Release
Valve for additional information on valve installation
and performance.
Air Release Valve Installation
The Automatic Air Release Valve must be inde
pendently mounted in a horizontal position be
tween the pump discharge port
and the inlet side of
the discharge check valve (see Figure 3). The inlet
opening in the Air Release Valve is equipped with
standard 1‐inch NPT pipe threads.