(0707)
For lighter loads (0-15 PSI or up to maximum vacuum) the diaphragm may operate successfully
for a year or more. The corrosive content of the gas media being pumped can effect the recom-
mended inspection and replacement cycle of the diaphragm.
*Diaphragms require close precision tolerance, therefore only ADI diaphragms should be
used as replacements.
C. Disassembly of Head Section and Service Diaphragm
1. Remove head section by unscrewing the four large bolts. A flat-bladed screw driver may be
needed to gently pry the head free of the service diaphragm. **If you have Teflon® coating on
the heads use caution not to scratch the surface.
2. The valve body can then be removed by unscrewing the two smaller screws (also accessible
on the top of the head section). This part may be freed by gently tapping on these two screws
after they have been loosened about three or four turns. When the valve body is removed, check
all internal surfaces for any accumulation of dirt. The two valve discs can be wiped clean and
replaced as long as they appear unaffected by usage. The valve gasket can be easily removed and
should be inspected. As a matter of good practice, the valve discs and valve gasket should be
replaced during any routine maintenance check of the head section. A once a year routine proce-
dure is recommended.
3. The service diaphragm is secured by the single screw in its center. Remove this screw with a
5/32" Allen wrench. The diaphragm and its clamping plate should be easily lifted off. Some
slight adherence to the metal may occur if the diaphragm has been in use for a long period. Be-
fore inserting the diaphragm cap screw (19007) apply a small amount of Teflon® paste or a Tef-
lon® Washer seal (23001), (
do not use Teflon® tape
), then tighten the cap screw.
NOTE: When replacing the service diaphragm, be sure the four projecting studs of the base cast-
ing are properly located in the four outer holes provided in the diaphragm before the part is
clamped in place. Be sure the diaphragm plate is firmly replaced with its center screw.
D. Disassembly of the Connecting Rod
1. Remove head section and service diaphragm as described in (C) above.
2. Remove the front plate from the face of the base casting by removing the four retaining
screws.
3. Using a hex socket wrench, remove the hex head bolt on the connecting rod top surface. This
will release the connecting rod cap (3001) which may then be lifted off.
4. The connecting rod assembly on single head units, including the counterweight, is held in
place by the counterweight screw. This can be loosened by a 3/16" Allen wrench. The connect-
ing rod assembly may then be slid off the motor shaft. On the dual and quad head units the as-
sembly is held in place by the set screw. This can be loosened by a 1/8" Allen wrench and the
assembly may then be slid off the motor shaft.
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