Edwards Vapour Diffusion Vacuum Pump Diffstak 100/300M

Is the Diffstak boiler operating at a higher than normal temperature?

Allow the pump to cool and open it to atmospheric pressure.

Remove the dipstick and 'O' ring.

Check the fluid-level on the dipstick.

Is the fluid-level below the notch mark?

Ensure all traces of the cleaning solution are removed before operating the pump.

Select the cleaning solution suitable for the type of pump fluid used.

Ensure the jet assembly is vapour de-greased.

Inspect the pump interior for solid deposits of pump fluid around the base.

Is there a solid deposit of pump fluid around the base?

Use an ultrasonic cleaning bath to remove solid deposits if present.

Removal of Damaged Position Indicators

Refer to Figure 27 and loosen the clamp screw on the valve open position indicator.

Slide the valve open position indicator down the dovetail groove and out of the cylinder.

Loosen the clamp screw on the valve closed position indicator.

Slide the valve closed position indicator down the dovetail groove and out of the cylinder.

Installation of New Position Indicators

Ensure the dovetail groove is clean.

Slide the new valve closed position indicator into the dovetail groove, ensuring correct orientation as shown in Figure 27.

Adjust the position indicator until the gap between the position indicator and the valve actuator is correct.

Adjust Valve Closed Position Indicator

Loosen the clamp screw (7) on the valve closed position indicator (1)

Slide the position indicator in the dovetail groove (3) until the gap (2) is correct

Apply a suitable thread sealant to the clamp screw (7)

Tighten the clamp screw to a torque of 0.4 Nm

Adjust Valve Open Position Indicator

Repeat Steps 1 to 3 for the valve open position indicator (6)

Adjust the gap (5) between the valve open position indicator and the end of the pneumatic actuator

Move the valve to the fully open position

Remove the screws securing the valve-plate to the shaft

Carefully withdraw the valve-shaft complete with its lever from the valve-body