Edwards Vapour Diffusion Vacuum Pump Diffstak 100/300P

Adjust Valve Closed Position Indicator

Loosen the clamp screw on the valve closed position indicator

Slide the position indicator in the dovetail groove until the gap between the position indicator and the valve actuator is correct

Apply a suitable thread sealant to the clamp screw

Tighten the clamp screw to a torque of 0.4 Nm

Adjust Valve Open Position Indicator

Repeat the adjustment steps for the valve open position indicator

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?

If solid deposit is present, use an ultrasonic cleaning bath to remove it.

Isolate the Diffstak from the electrical supply

Remove the retaining screws and detach the cover from the terminal-box

Disconnect the incoming electrical supply cables and the earth (ground) cable at the terminal-block

Remove the nut from the radiation shield/heater assembly securing stud

Lower the complete radiation shield and heater assembly

Disconnect the electrical connections at the heater and remove the heater

Replace the defective heater(s)

Reconnect the heater electrical supply cables to the terminal-block

Coat the thread of the radiation shield/heater assembly securing stud with an anti-seize compound

Open the valve pneumatically and disconnect the pneumatic pipelines from the Diffstak

Remove the socket-head screws securing the valve-plate to the shaft and detach the valve-plate

Valve-shaft removal for Diffstak 63/150P and 100/300P pumps

Detach the red safety cover from the pneumatic actuator

Remove the three screws retaining the actuator to the boss on the valve-body

Carefully withdraw the valve-shaft (complete with actuator) from the valve-body

Valve-shaft removal for Diffstak 160/700P pumps

Remove the two screws retaining the switch mounting bracket to the valve-body and detach the bracket

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

Switch on the pump heater for a maximum time of two minutes to warm the pump fluid.

Ensure the pump fluid is not vaporised.

Disconnect the Diffstak from the electrical supplies.

Detach the Diffstak from your vacuum system.

Remove the drain-plug and allow the fluid to drain from the pump.