Milton Roy Dosing Pump GB80 (SS)

Fit new O-Rings into position on the ball guide and seat

Drop the ball into the curved inner chamber end of the ball guide

Sit the ball guide on a flat surface with the ball facing upwards

Position seat on the ball guide, trapping the ball inside

Press the seat into the ball guide with firm, even pressure

Position the union end onto the correct end of the ball guide

Ensure all shut-off valves are closed and all pressure is bled from the liquid end.

Disassembly (Refer to Figures 7 and 8)

Set the stroke adjusting knob to 100%.

Disconnect the suction and discharge piping.

Unscrew the six diaphragm head bolts.

Remove the diaphragm head assembly from the pump body.

Turn the motor fan by hand until the end of the diaphragm assembly is fully forward, and unscrew the diaphragm assembly from the connecting rod.

Reassembly (Refer to Figures 7 and 8)

Drop the ball into the curved inner chamber end of the ball guide.

Place a new gasket on the rim of the ball guide, and sit the seat on top of the ball guide, trapping the ball and gasket between the seat and ball guide.

Position the connection (435) onto the correct end of the ball guide with a gasket trapped between the two metal surfaces.

Position the check valve assembly onto the liquid end, trapping a gasket between the two metal surfaces. (Seat and pump head).

Slide the valve clamp (437) over the connection (435) and screw into the liquid end using the three screws (441,442) and their split washers (439).

Unscrew the ball guide (424) from the liquid end

Remove and discard the O-Rings (419)

Carefully clean any parts to be reused

Do you suspect the check valve may be damaged or worn?

Replace the entire check valve assembly if damage or wear is suspected

Pre-Replacement Safety Measures

Ensure shut-off valves are closed

Inspection of Check Valve Components

Inspect ball check for chemical or physical damage

Inspect seat for sharp edge and damage

Replacement of Check Valve Components

Systematically change O-Rings and/or gaskets during valve replacement