MAINTENANCE

SERVICING THE DIAPHRAGM

1. Remove nuts and screws around the diaphragm top cap. Lift off cap and diaphragm and inspect for wear.
   
   
2. To replace diaphragm, place top cap upside down on a bench. Place a new diaphragm, which may be flat or molded, on the cap.
   
   
3. With a molded diaphragm, insert screws up through holes in top cap and through the diaphragm. Place cap and diaphragm back on housing and replace nuts and tighten for an air tight seal. Over tightening may distort the cap and cause extra leakage.
   
   
4. With a flat diaphragm, insert the screws up through holes in cap and diaphragm. Insert one at a time working your way around the diaphragm. (On some sizes it may help to skip some screws and then go back to fill in the blanks.) The diaphragm may appear to be too large, but leave the extra material buckled up between the screws. The diaphragm will end up bulged upward at the middle. Once all screws are through, push the diaphragm down into the cap. It is normal for some buckling to occur, but this will soon go away in operation, and the diaphragm will mold to the proper shape. Place cap and diaphragm back on housing and start the nuts on the screws. It may be helpful to use a C-clamp to draw the housing down enough to start the screws. Tighten all screws for an air tight seal. Over tightening may distort the cap and cause extra leakage.
   
   
5. After reinstalling actuator assembly operate valve several times to check for leaks and form the diaphragm. Remember that air pressures over 35 PSI will only reduce the life of the diaphragm and other components.