Haskel 8 Serie Instructions De Fonctionnement Et D'entretien page 10

5.5.3 Remove (8) nuts, lock washers and flat washers securing (4) air drive main tie bolts and carefully
separate drive end caps (with intact pump section) to gain access to drive piston and cross pins securing
rod to drive piston assembly.
5.5.4 Remove (1) E-ring, push out (1) cross pin and disconnect (1) piston rod from piston assembly so
that air barrel and drive piston o-ring can be removed for inspection.
5.5.5 Inspect barrel to end cap static seal o-rings.
Pull barrel off drive piston and inspect large drive
piston seal.
NOTE: If the large o-ring is "tight" in the groove, it is
probably swollen and should be replaced.
Replace if damaged or worn. Also, check large drive
piston o-ring for shrinkage by laying it on a flat
surface. Then place a clean unlubricated air barrel
over it. The o-ring outside diameter must be large
enough so that it can be picked up with the barrel. If
not, discard and replace. (Ref. Fig. 8.)
NOTE: Severe cycling modification 54312
incorporates p/n 26824-8 TFE glider cap over the o-ring. This eliminates any need for lubrication. Do not
lubricate.
5.5.6 Clean all parts and inspect for grooved, scratched or scored wear surfaces.
5.5.7 Apply Haskel 50866 Lubricant to all o-rings and inner surface of barrel (but not if 26824-8 TFE glider
is used) and reassemble drive section parts, end caps with pump sections, gas and associated plumbing
lines in reverse order of disassembly instructions.
5.5.8 Alternately (crosswise) torque tie rod nuts to 250 to 300 in-lbs.
5.6 Pump Section Check Valves
The parts makeup of the check valves in each model is clearly depicted on its individual assembly
drawing attached to each pump at time of shipment from the factory. These checks are two basic types:
Ball and Flat disk.
5.6.1 The Ball type is used for both inlet and outlet in some models. Models with the outlet check in the
pump end caps incorporate a PTFE semi-soft seat. Models with the outlet check in the piston do not.
(Ref. 5.7.1)
5.6.2 The Flat disk type is used for inlet only in some models (-25 thru -100) to provide higher flow
capacity. Refer to the assembly drawing for parts detail and order of disassembly and reassembly.
5.6.3 The round wire snap ring retaining the 3/4" NPT semisoft seat Ball checks is easily removed by first
uniformly depressing the cage with two screw drivers. Reinsertion of the ring can also be done this way
(or with Haskel p/n 29370 tool).
NOTE: If the TFE seat is found damaged and no replacement is immediately available, the check can be
reassembled without it. Pumping action should still be satisfactory. Replace TFE set as soon as available.
5.6.3 The Flat disk type inlet check has fewer parts but more potential for damage of the light actuating
spring (p/n 17615) during reassembly. Be certain that the spring ends are square without crossed wires. If
not, discard the spring. As the end cap is tightened, frequently check the spring action of the disk with
your finger to make sure it opens and closes easily with no tendency to cock or hang up.
5.6.4 Clean all parts (Ref. paragraph 5.1) and inspect for nicks, grooves and deformation. Renew any that
are damaged.
5.6.5 DO NOT apply lubricant to any of these parts.
NOTE: To properly center the parts during reassembly, we recommend that the ports be in a vertical
position. This may require the removal of the end cap in some instances.
8" Drive Liquid Pumps • OM-LP-800F
Figure 8. Checking drive piston o-ring
for shrinkage
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