Wanner Engineering Pump G-25

Lift the diaphragm by one edge and turn the pump shaft until the diaphragm pulls up.

Insert an Allen wrench through one of the holes to hold the diaphragm up.

Diaphragm Removal and Inspection

Remove the screw (19), O-ring (20), and follower (21) in the center of the diaphragm.

Inspect the diaphragm for the following issues

Inspect the plunger (23) for any rough surfaces or edges.

Smooth the surfaces and edges as necessary with emery cloth or a fine file.

Measure the oil level in the upper oil reservoir

Is the oil clean and uncontaminated?

Remove contaminated oil if present

Ensure all safety precautions are taken for safe handling of the fluid being pumped.

Provide adequate catch basins for fluid drainage.

Use appropriate plumbing from drain ports when flushing the pump and system with antifreeze.

Shutdown Procedure During Freezing Temperatures

Adjust the discharge pressure regulating valve so the pump runs under minimum pressure.

Open any draincocks in system piping and collect drainage.

Inlet and Outlet Valve Inspection

Replace worn spring retainer (16)

Replace valve spring (14) if shorter than a new spring

Replace excessively worn valve poppet (13)

Inspect valve seat (12) for wear and replace if necessary

Install new O-ring (11) on valve seat (12)

Reinstallation of Valve Assemblies

Clean valve ports and shoulders with emery cloth

Ensure the pump is turned off and cooled down

Gather necessary tools and materials for oil change

Remove the drain plug cap (34) at the bottom of the pump

Ensure all oil and accumulated sediment have drained out

Verify oil viscosity is between 16-20 cST (80-100 SSU)

Is an oil cooler installed if process fluid or hydraulic end oil exceeds 180°F (82°C)?