Discharge Check Valve; Maintenance; Disassembly; Assembly - Generac Power Systems MAGNUM Owner's Manual

the valve seat. Also check the prime valve for any dam-
age or debris.

Discharge Check Valve

The discharge check valve enables automatic priming of
the pump by closing the air leakage path on the discharge
side of the pump. This allows the primer to pull the pump
casing vacuum down sufficiently that atmospheric
pressure will push the check valve open and allow the flow
of liquid through the discharge.
The presence of the check valve, as with any other fitting
in the piping system, add resistance (pipe friction) to the
total head the pump must overcome during normal
operation, and not just while priming for start-up. The
amount of this added friction varies with the rate of flow,
1. Cover bolts
2. Disc
3. Cover

Disassembly

The valve can be disassembled without removing it from
the pump.
WARNING CAUTION
Personal injury. Drain water line to relieve pressure
before removing cover. Failure to do so could result
in minor or moderate injury.
To relieve pressure and drain the pump:
Remove the cover bolts from the top cover.
1.
Pry the cover loose and lift off the valve body.
2.
Owner's Manual for Dry-Prime Diesel Trash Pumps
as well as with pipe size. To determine the extent of the
addition for a specific performance point, refer to the flow
rate charts. See
If the check valve disc should be prevented from completely
closing due to debris or damage, the pump will not re-prime.
In such a case it will be necessary to remove the inspection
cover and clean out the debris or service the valve.

Maintenance

The check valve requires no scheduled lubrication or
maintenance. For service or inspection, the valve can be
serviced without disconnecting the inlet or outlet hoses. If
inspection of the valve is required, follow the disassembly
instructions.
2
1
Figure 4-5. Discharge Check Valve
4. Gasket
5. Check valve body
Remove the disc and inspect for cracks, tears, or
3.
damage in the rubber sealing surface.
Clean and inspect the parts. Replace worn parts as
4.
necessary.

Assembly

All parts must be cleaned. Gasket surfaces should be
cleaned with a stiff wire brush in the direction of the
serrations or machine marks. Worn parts and gaskets
(000270)
should be replaced during assembly.
Place the disc over the seat with the beaded seat-
1.
ing surface directed down.
Flow Rates.
3 1
4
5
002310
Maintenance
53