Pulsafeeder PulsaPro 900 EN - Manual (Page 31)

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7.3.1 Check Valve Removal
T AKE ALL PRECAUTIONS TO PREVENT ENVIRONMENTAL AND PERSONNEL EXPOSURE
TO HAZARDOUS MATERIALS .
1. Disconnect the power source to the drive motor (e.g., lockout/tagout the motor disconnect).
2. Relieve all pressure from the piping system.
3. Close the suction and discharge shutoff valves (refer to Figure 8A).
4. Loosen the suction valve tie-bar bolts and spring the suction piping slightly to drain any liquid
from the reagent head cavity. If the piping is closely connected it may be necessary to
disconnect a union or flange.
5. Remove the suction check valve assembly, holding it together as a unit.
6. Loosen the tie bar bolts on the discharge valve and spring the piping slightly to drain any liquid.
7. Remove the discharge check valve assembly, holding it together as a unit.
7.3.2 Ball Valve – Inspection and Repair
1. Disassemble both the suction and discharge check valves.
The ball seats should have sharp edges or a small chamfer and be free from dents or nicks.
2. Examine components for wear by holding the ball firmly against its mating seat in front of a
bright light to inspect for fit.
Observation of light between the ball and seat is cause for replacement of either or both
components.
3. Reassemble both valves using new parts as required. The o-rings should always be replaced.
7.3.3 Disk Valve – Inspection and Repair
1. Disassemble valves and inspect components for wear.
The seats and lower disk surfaces contacting the seats should remain flat and smooth.
Although it is normal for the o-ring in the seat to be flattened after significant use,
replacement is recommended as a part of valve maintenance.
2. The seat o-ring is captured by an internal lip in its groove in the seat. Removal requires the
following destructive procedure:
a) Position a small blade type screwdriver against the outer edge of the o-ring at an angle of
approximately 45 degrees.
b) Taking care not to damage the sides of the seat, drive the screwdriver into the o-ring.
c) Using the screwdriver, pry one section of the o-ring out of the groove.
d) Grip the O-Ring with pliers, and remove it from the seat.
3. To install the replacement seat o-ring; place it on the seat above the groove.
4. Position a flat metal object over the o-ring
5. Apply uniform light pressure using a hand arbor press.
The slight movement that accompanies seating can be easily felt through the press
handle.
D O NOT TRY TO INSTALL THE RING BY HAMMERING , AS THE SEATING WILL NOT BE
UNIFORM . THE RING MAY BE DAMAGED AND THE PUMP PERFORMANCE MAY BE
IMPAIRED .
6. Reassemble both valves using new parts as required. Sealing O-Rings should always be
replaced.