Definox Automatic Changeover Valve DN 100-104

Ensure air supply is closed and circuit is purged

Ensure mains supply is switched off (if applicable)

Disassembling the Signalling Box

Detach the signalling unit from the actuator if necessary

Refer to maintenance notices for control top fitting/removal

Disassembling the DCX3 Valve Clamp Collar

Supply air to the NC actuator to relieve pressure on the clamp collar

Refit the stem/piston and spring assembly the other way around in the body

Check that the snap-ring is properly positioned in its recess

Is the snap-ring damaged or deformed?

Is there any movement of the actuator body during the opening/close operation?

Remove the defective seal using a cutter without marking the bearing surface of the plug.

Protect the stainless steel surface using the edge of a steel rule or a plastic off-cut.

Set oven temperature to 140°C (+/- 3%).

Ensure the oven temperature does not exceed 200°C.

Place the new seals in the oven for 30 minutes.

Insert the seal quickly from one side of the groove.

Use medium thread lock compound to lock the plug during reassembly on the actuator

Retighten the plug of diaphragm valves after first usage with temperature

Supply air to the actuator before tightening the clamp collars

Is the valve operating normally?

Describe any difficulties encountered during operations

Ensure the actuator configuration is correct (NC, NO, or DA)

Lubricate all parts with appropriate lubricant

Center the piston using the guide pin on the actuator stem

Fit the lantern seal [18] [18b] carefully using the press

Position the snap-ring (16) properly in the recess of the body before releasing pressure