FF-MM-361-REV - 02
Operation and Maintenance Guide DP 40 Metal Series
Page 9
backup diaphragm (11), PTFE diaphragm (11A) & inner
flange (5). Now pull out the half shaft assembly out of the
shaft housing (1).
d.
Now hold the shaft (7) in a vice with proper
packing. Care must be taken not to damage the shaft outer
surface. Now remove the outer flange (5) with spanner.
*For ALT/SST series remove the bolt (24) and remove the
outer flange (5), Backup diaphragm (11) & PTFE diaphragm
(11A).
e.
Now replace the diaphragms (11). Ensure that dia-
phragm orientation is correct, i.e. For ALB/ ALN/ ALV the
sticker side of the diaphragm (11) to be located in the outer
chamber (6). Now assemble the outer flange (5) in reverse
manner and remove the half shaft assembly from vice.
* For ALT & SST model the convex side of outer ring PTFE
diaphragm (11A) to be located in outer chamber (6). For the
backup diaphragm (11) the larger side of outer ring to be
located in shaft housing (1) & small in the concave groove of
PTFE diaphragm (11A).
* For ALS/ ALH model AIR SIDE marking to be located
toward the shaft housing (1).
f.
Lubricate the edge of the shaft with specified
lubricant. Slowly insert the shaft with rotating motion. Care
should be taken not to damage the rubber rings (8).
g.
Once the half shaft open portion comes out of the
bush, follow the procedure in reverse manner as described in
part (a) & (b) and assemble the pump.
2)
Replacement of Shaft O rings
a.
For removing the rubber rings from bush, first
follow the step a, b & c from the diaphragm replacement.
b.
Now remove the seals with the help of needle Nose
pliers. Care should be taken not to damage the inner face of
bush.
c.
Once all the old seals are have been removed, the
inside of the bushing should be cleaned to ensure no debris
is left that may damage to new seals (Pressurized air is pref-
erable).
d.
These following tools can be used to aid in the
installation of new seals:
●
Needle Nose pliers
●
Phillips Screwdriver
●
Electrical Tape
e.
Wrap electrical tape around each leg of the needle
nose pliers (heat shrink may also be used) . This is done to
prevent damaging the inside portion of the new seals.
f.
With a new seal in hand, place the two legs of the
nose pliers inside the seal ring. Open the pliers as wide as
the seal diameter will allow, then two fingers pull down on
the top portion of the seal to form kidney bean shape.
g.
Lightly clamp the pliers together to hold the seal
into the kidney shape. Be sure to pull the seal into as tight of
a kidney shape as possible, this will allow the seal to travel
down the bushing bore easier.
h.
With the seal clamped in the pliers, insert the seal
into the bushing bore and position the bottom of the seal
into the correct groove. Once the bottom of the seal is seated
in the groove, release the clamp pressure on the pliers. This
will allow the seal to partially snap back to its original shape.
i.
After the pliers are removed, you will notice a slight
bump in the seal shape. Before the seal can be properly
resized, the bump in the seal should be removed as much
as possible. This can be done with either the Phillips screw
driver or your finger, apply light pressure to the peak of the
bump. This pressure will cause the bump to be almost com-
pletely eliminated.
j.
Lubricate the edge of the shaft with specified lubri-
cant.
k.
Slowly insert the shaft with rotating motion. This
will complete the resizing of the seals.
l.
Perform these steps for the remaining seals.
3) Replacement of Ball seat & Ball
a)
Follow the step (a) of diaphragm replacement.
Replace the ball (12) & seat (13) with new one.
* For ALT, SST series change the valve seat
(13) &oring (13A) with new one.
4) Replacement of air valve and oring
of end cap
a)
Unscrew nut (28) from the shaft housing (1).
Remove the air valve assembly along with the bolt (25). Now
remove the circlips (21) from both ends. Now with the help
of bolt (25) pull the end cap (17) & (19) from both ends.
Now slide out the air valve (16). Change the oring (20) of
both end caps.
b)
While assembly first put the end cap with pin (19)
in air valve body (14). Make sure the notch of end cap (19)
matches with the drill hole of body. Push the end cap with
oring (20) gently. Now fit the circlip (21). Now slide the air
valve from other side ensuring the drill portion located in
the pin of end cap (19). Now push the end cap (17) with
oring (20) from the other end and fit the circlip.
c)
You can also change the gasket for air valve body
(15) & blocking pad (23). Now assemble the air valve assem-
bly in reverse manner. While assembly make sure to put the
spring washer (29) along with the nut (28).