Blackmer Pump GNX4A

Relief Valve Setting and Adjustment

Ensure safety precautions are in place

Remove the relief valve cap and gasket

Loosen the locknut, if equipped

Turn the adjusting screw inward (clockwise)

Inspect the R/V cap gasket and replace if required

Reattach the R/V cap gasket and cap

Disconnect and lockout electrical power or engine drive before maintenance

Relieve system pressure before maintenance

Flush and decontaminate system if pumping hazardous or toxic fluids

Ensure pump is not running before lubrication

Check grease relief fittings (76A) for proper function after painting

Remove the grease relief fittings (76A) from the bearing covers (27, 27A)

Check if any O-rings have been removed or disturbed during disassembly

Replace disturbed or removed O-rings with new ones

Heat PTFE O-rings in hot water before installation

Mechanical Seal Inspection and Replacement

Is there excessive or continuous leakage from the tell-tale hole in the bearing cover?

Replace the entire mechanical seal if leakage is detected

Refer to 'General Pump Troubleshooting' for possible causes of seal leakage

Check for a vent on the gear unit and remove the sealing plug if applicable

Ensure no excessive pressure build-up in the gear unit

Remove all anti-corrosive metal protectant from bare metal surfaces

Drain the reducer and refill with the proper type and amount of lubricant

Check the lubricant level and type in the gear unit

Open the discharge valve and close the intake valve

Bleed air into the pump through the intake gauge plug hole or auxiliary fitting

Pump air for 30 second intervals

Run a system compatible flushing fluid through the pump

Repeat initial flushing procedure to remove the flushing fluid