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MAINTENANCE
We have designed Eldex Metering Pumps to give years of trouble-free service. By following a few simple
maintenance procedures, you can ensure the longevity of your pump.
Cleaning
Before cleaning your pump, disconnect the pump from the power supply. Cleaning can be accomplished by
wiping down with a damp cloth.
Piston Seal
The seal material used is usually a specially
formulated PTFE. It is the standard seal
material because of its broad range of chemical
compatibility, its mechanical properties, and its
stability in reciprocating applications.
The length of service to be expected from any given piston seal depends on a wide variety of factors, including
the fluid being pumped and the pressure of the system. It is critically important that the seal be replaced
immediately upon failure, or better yet, before failure, because fluid can travel into the mechanical housing of
the pump and cause corrosion damage.
When a leak occurs, you may notice fluid just underneath the liquid end. However, a leak may not always be
visible, particularly at low flow rates. We suggest you place a wick or litmus paper up the drain slots just
underneath the liquid end. You should remove the wick or litmus paper periodically and check for wetness or
color changes to see if leakage has occurred.
Piston seal life can often be significantly extended by using the piston wash system integrated in the pump.
Replacing the Piston Seal
1.
Use tools supplied with Part Nos, 5911, (3/32” installation tool and 5/32 hex key); 5941(installation tool
and 5/32 hex key); 5944, (1/4” diameter dowel pin and 5/32 hex key).
2.
Send the piston to the home position. Turn the power switch to OFF.
3.
Remove the liquid end from the pump as follows: Unscrew the two 5/32” socket head bolts. Pull the
liquid end straight out from the pump housing, in line with the axis of the piston. If you cock or tilt the
liquid end, you may break the piston. See Figure 4.1.
Figure 4.1: Pump Assembly
TIP: We have found, especially with metal-free seals, that
“breaking-in” the seals with IPA or methanol for an hour
or so, under conditions similar to your expected operating
conditions enhances seal life.
Liquid End
Wash Ports
Piston Seal
Backup Washer
Retainer/Wash
Piston