MAINTENANCE

SERVICING THE PACKERS

1. Remove the clevis pin by applying low pressure air (10-15psi) to the diaphragm chamber to partially stroke the valve. With spring tension now relieved and the cotter pin removed, the clevis pin can be easily pulled out. Remove the nuts or cap screws holding the housing assembly to the body. CAUTION DO NOT PINCH FINGERS.
   
   
2. Lift housing assembly straight off the body and set aside, being careful not to damage the machined bottom surfaces or inside diameter. The top packer is now exposed.
   
   
3. To expose the bottom packer, remove the nuts or cap screws holding the bottom cap.
   
   
4. Remove the bottom cap and set aside, being careful not to damage the machined surfaces or inside diameter. The bottom packer is now exposed.
   
   
5. If the valve has been removed from the piping, a blast of air from an air gun blown into the open ports may push the packers out. If this is not convenient, a packing hook or sharp instrument may be used to grab the packer and pull it out of the valve. Be careful not to scratch the inside diameter of the body, or the surface of the piston or disc that moves in the packer.
   
   
6. Inspect machined surfaces for signs of roughness or nicks. A rough surface on the disc or piston will shorten the life of the new packers. Replace parts as necessary. A deep nick in the body may also cause the packer to leak. Sometimes, smoothing the nick with emery cloth will help.
   
   
7. Look at the header rings underneath the packers and replace if they are broken, badly nicked, or cracked. These rings do not compress the packers for a tighter seal. Their function is merely as a guard and support for the packers, which are energized by the fluid under pressure.
   
   
8. To replace packers, lubricate them with a good grease or oil compatible with the material, and place over the disc or piston and into the body with lips facing the pressure side or inside of the valve.
   
   
9. Carefully ease the outer lips into the body, being careful not to nick them. A dull instrument can be used to help push the lips into the body, if necessary.
   
   
10. Once both packers are in place, prepare to reinstall the bottom cap and housing assembly. Check the machined surfaces of the bottom cap and housing for damage. Smooth any nicks or burrs, or replace as necessary.
    
    
11. Replace bottom cap and housing assembly, reinstalling nuts only finger tight.
    
    
12. Apply low pressure air to the diaphragm chamber again to stroke the valve just enough to replace the clevis pin. Caution: be careful not to pinch a finger when the stem assembly is moving. Replace cotter pin.
    
    
13. Stroke the valve several times to make sure it shifts smoothly and is properly aligned, and then tighten nuts or cap screws on the bottom cap and housing assembly.
    
    
14. Your repair is now complete and the valve is ready to test and reinstall.