Gorman-Rupp Pumps 3D-E1.5 1P 883504 and up - Manual (Page 10)

D SERIES OM-03604
PAGE B - 3 INSTALLATION
prime and allow the liquid in the chamber to drain
away through the suction line.
If the pump is mounted in a system with fixed, rigid
piping, it is recommended that a flexible connec­
tion be installed at or near the suction and dis­
charge ports to absorb shock which would other­
wise be transmitted through the drive train and
greatly accelerate pump wear.
In a fixed piping installation, properly sized surge
suppressors must be installed in both suction and
discharge lines. If commercial surge suppressors
are not readily available, air chambers may be fab­
ricated from pipe as shown in Figure 2.
AIR CHAMBERS
(18 TO 24 INCH LENGTHS OF
6 TO 8 INCH DIAMETER PIPE
WITH WELDED CAPS)
DISCHARGE
CHAMBER
DISCHARGE
FLEXIBLE JOINT
FLEXIBLE JOINT
SUCTION
CHAMBER
1/2‐INCH VALVE FOR
RECHARGING AIR
CHAMBER WITH
COMPRESSED AIR
(ALSO ON DISCHARGE
CHAMBER)
SUCTION
NOTE: INSTALL AIR CHAMBERS OFF FLOW LINE TEES
TO AVOID SURFACE TURBULENCE WITHIN CHAMBERS.
Figure 2. Fixed Piping Installation
Note that the air chambers have not been installed
directly in the flow line, but have been installed off
tees to avoid turbulence within the chambers. The
air chambers are fitted with valves to permit intro­
duction of small amounts of compressed air to fur­
ther dampen shock; this compressed air will leak
away during operation, and should be replaced
from time to time. If the suction chamber floods,
open the suction chamber valve to break prime
and allow the liquid in chamber to drain through
the suction line.
Gauges
If discharge pressure and vacuum suction gauges
are desired, drill and tap the suction and discharge
lines not less than 18 inches (457,2 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic
readings.
SUCTION LINES
To avoid air pockets which could affect pump prim­
ing, the suction line must be as short and direct as
possible. When operation involves a suction lift, the
line must always slope upward to the pump from
the source of the liquid being pumped; if the line
slopes down to the pump at any point along the
suction run, air pockets will be created.
NOTE
Maximum pump performance is realized at suction
lifts of 5 feet (1,5 m) or less. Use the shortest possi­
ble length of suction hose or piping; lengths of 25
feet (7,6 m) or longer will reduce the capacity of the
pump.