Milton Roy Dosing Pump GB803

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

Separate the following components

Remove and discard the three gaskets (419)

Were all parts cleaned properly?

List any chemicals used for cleaning and confirm compatibility with process liquid

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 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.

Slide the valve clamp over the connection and screw into the liquid end using the three screws and their split washers.

Ensure new gaskets are used and old gaskets are not reused.

Verify the correct assembly order for suction and discharge check valves as per Figure 12.

Ensure all shut-off valves are closed and all pressure has been bled from liquid end.

Drain oil from the pump by unscrewing the drain plug (20) and O-Ring (19).

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 (261) is fully forward, and unscrew the diaphragm from the connecting rod (60).

Unscrew the ball guide (424) from the liquid end

Remove and discard the O-Rings (419)

Carefully clean any parts to be reused

Is the check valve suspected to be damaged or worn?

Replace the entire check valve assembly if damaged or worn