Trebor 110R - Manual (Page 5)

MODEL 110R PUMP OPERATION / MAINTENANCE MANUAL PAGE 5
See Section 4.1 Preventative Maintenance Schedule for additional requirements
for high temperature applications.
1.4 CHECK MUFFLER OPERATION
1.4.a Purpose

Permits pump to operate reliably in systems that incorporate a discharge fluid
“dead head” condition. (Fluid discharge line closed while pump air supply
remains on.)

Permits pump to operate reliably in systems that have the pump located at an
elevation below the liquid supply level. (Pump air supply remains on.)

Effectively reduces the amount of harmful acid vapors that can enter into the
pump’s internal air circuit components while the pump air supply is off. (A
common cause of shuttle and pilot valve failures.)
1.4.b Adjustment

The Check Muffler is preset at the factory to a setting that makes the pump
“Dead Cycle” at a slow constant rate with the fluid discharge port closed, and
the pump air supply at 45 psig. This setting also allows the pump to operate
with approximately 4 ft. (1 meter) of H
2
O positive fluid supply pressure.
“Deadheading” at other air supply pressure or with more positive fluid supply
pressure (fluid source above pump) may require user adjustment. The
adjustment should control the pump to a slow, steady
“Dead Cycle” rate with
no erratic cycling, ”machine gunning”, evident.
NOTE: If pump application does not require operation in either of these
conditions, loosen check muffler adjustment for minimum restriction.
NOTE: Air consumption during “Dead Cycling” is very little since the pump
diaphragms are displacing only internal bypass. “Dead Cycling” should be
considered as a normal standby idle mode.
Figure 1-2

Turn adjustment screw clockwise (CW) to increase backpressure.

Turn adjustment screw counter-clockwise (CCW) to decrease backpressure.
NOTE: Loosen locking nut prior to making adjustment and then re-tighten nut to
maintain adjustment.