Samson 3525 Mounting And Operating Instructions

38 EB 8823 ENMaintenance7.1.3 Replacing the seat andplugRisk of damage to the facing of the seat andplug due to abrasion and incorrect serviceor repair.The plug and seat facings are very sensitive.− Before unscrewing the bonnet from thebody, apply a signal pressure to the actua-tor to slightly lift the plug off the seat. Thisprevents the plug and seat from beingdamaged.− Always replace both the seat and plug.It is not necessary to remove the actuatorfrom the valve to replace the seat and theplug.When replacing the seat and plug, we alsorecommend replacing the packing. See sec-tion 7.1.2.1. Bend down the flap of the tab washer(224).2. Apply a signal pressure to the actuator toslightly lift the plug off the seat. Unscrewthe bonnet (2).3. Lift bonnet (2) and plug with plug stem(5) off the body (1). Remove tab washer(224).4. Replace O-rings (17) as described insection 7.1.1.5. Unscrew the seat (4) using a suitabletool.6. Remove seat ring gasket (127) from thebody (1) and carefully clean the sealingface. Insert a new seat ring gasket intothe body.7. Apply a suitable lubricant to the threadand the sealing cone of the new seat.8. Screw in the new seat (4) using a suit-able tool. Observe tightening torques.9. Carefully warm up the plug (29) so thatit can be removed from the plug stem(36) in the next step.10. Apply a signal pressure to the actuatorso that the flats at the plug stem (36)emerge from the bonnet. Place wrenchon flats.11. Place another wrench on the flats of theplug (29).12. Loosen plug with wrench while counter-ing with the top wrench.13. Apply suitable threadlocker to the threadof the new plug (29).14. Screw plug head (29) onto the plug stem(36) using a suitable tool. Observe tight-ening torques.15. Replace packing (15) as described insection 7.1.2.16. Apply a suitable lubricant to the bonnet(2).17. Place a new tab washer (224) onto thebonnet (2).NOTICE!NoteTip