Haskel 8 Serie Instructions De Fonctionnement Et D'entretien page 13

"pull" stroke, the piston opens the pilot vent valve. This vents all trapped pilot air enabling the spool to go
"up" (fig. 9) reversing the drive piston which is again powered right ("push").
6.2.3 DRIVE SECTION ACTION SUMMARY
Drive piston moving:
To the right (push stroke Fig 9)
To the right (pull stroke Fig 10)
NOTE: The drive cylinder (barrel) and end caps are symmetrical. Therefore the cycling valve assembly
and flow fitting can be reversed if desired to fit the confines of a particular installation. This can be done in
the field or specified at time of order (modification 51638.) If reversed, the terms "upper, lower, right and
left" in the above chart also reverse.
6.3 Testing - Drive Section
Normally this section will require the most attention for operational integrity. The best way to evaluate its
condition is to stall the pump end (or ends). This assumes that the pump section(s) is functioning
properly. Connect the pump inlet (or inlets) to a source of compatible liquid. Connect the outlet (or outlets)
to a suitable outlet line, pressure gauge and shut-off valve.
Open the valve to atmosphere (or back to fluid source). Apply air to the drive regulated to about 30 psi.
Allow the pumping action to purge the liquid of entrained air. Shut-off the outlet valve.
NOTE: If the unit is already installed in a liquid system and the downstream valving does not directly
connect back to the liquid source, shut-off the outlet and then loosen a fitting anywhere in the line until air
free liquid appears. Tighten the fitting. The pump should stall.
6.3.1 Refer to figures 9 and 10. Install a 0-160 psi gauge in the 1/8" NPT pilot charge gauge port. Stall the
unit. Observe and listen for leakage.
6.3.2 If the drive is on the "push" stroke, the pilot charge pressure should be close to zero with no
evidence of pilot air leakage into the pilot system when the pilot charge valve is closed (its orifice will
dissipate a small leak).
6.3.3 If the drive is on the "pull stroke", the pilot charge pressure should hold solidly verifying minor or no
leakage past the trapped pilot air seal nor the pilot vent valve (if minor, the orifice in the pilot charge valve
will make it up).
6.3.4 Spool seal leakage: With the standard o-ring sealed spool at stall there should be no audible "hiss"
from either exhaust port. If there is, the faulty spool or sleeve o-ring can be quickly identified from fig. 9 or
10.
NOTE: With extreme cycling service modification 54312, slight spool seal "hiss" is normal.
8" Drive Liquid Pumps • OM-LP-800F
Drive exhausts:
From "lower" port.
From "upper" port.
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Pilot system is:
Vented
Charged