Zenith Pumps manual Cleaning Inspection Repair and Service, Disassembly

Cleaning,

Inspection,

Repair and

Service

After removal from the system, the assem- bled pump can be cleaned by placing it in a suitable furnace (i.e. vacuum oven, fluidized bed, etc.) and slowly increasing the temperature to 800-850° F in no less than two hours. Special care should be taken to avoid flashing of the polymer. Control of temperature is essential as it is possible to draw back the hardness of the steel and affect dimensional stability if the pump is overheated. The time to com- pletely carbonize the polymer is three to twelve hours, depending on the polymer, temperature, pump size and furnace load.

The pump must be gradually cooled to room temperature (no forced cooling or quenching), then disassembled and cleaned as instructed in the following section. Close adherence to these instruc- tions should be maintained for maximum pump life and performance.

It is recommended that pump users institute a program of dimensional inspec- tion of critical parts in order to keep main- tenance and operating costs at a minimum. By noting the performance of a pump immediately before removing it from service and correlating the performance to meas- ured component wear, the user can establish the maximum wear limits for the pump’s critical components. Further, he can predict the service life of the pump, and schedule his downtime accordingly.

After a pump has been disassembled,

all parts should be carefully inspected for nicks, burrs, scoring or other signs of wear. The side plates, D-bearings (and sides of the gears on the 3.0 cc/rev and smaller pumps) can be hand blocked on 600 grit paper, and any nick or burrs and other sharp edges very lightly touched with an Arkansas stone.

Note: After cleaning, all seals, O-rings and fasteners must be discarded.

CAUTION: As the thickness relation- ship between metering gears, center plate and D-bearings is critical to metering performance, care should be taken that these parts are only polished and that no metal is removed. Lapping of these components should not be done under any circumstances.

As with any other Zenith pumps, PEP-II pumps may be returned to Zenith for complete rehabilitation as necessary. This procedure may be desirable if only a few pumps are involved. If a large number of pumps are to be maintained at the user’s plant, it may be worthwhile to have key maintenance personnel attend a mainte- nance seminar at the Zenith factory to view the manufacturing, gauging and assembly techniques involved in producing the PEP-II pump. In addition, Zenith also offers a contract service program. Please contact Zenith for further information on these services.

Disassembly	These instructions should be thoroughly
	read and understood before starting dis-
	assembly.
	General instructions that should be
	observed to ensure correct disassembly
	of the pump are as follows:
	• If the pump is to be disassembled
	on a regular basis, set up a room with a
	separate clean area with all the tools
	required for disassembly, reassembly and
	storage.
	• During disassembly, note the loca-
	tion and orientation of all parts to ensure
	proper reassembly.
	• Use a soft-jawed vise to hold the
	pump during disassembly.
	When maintenance is required, refer
	to the exploded view and disassemble the
	pump as follows:
	CAUTION: Careful handling of the parts
	is imperative. Do not drop or allow parts
	to strike each other. The slightest nick or
	burr can cause difficulty in reassembly and
	may cause further damage to the pump.

1)Clearly mark which side of the pump is the inlet port and drive input side.

2)Remove the screws securing the Rheoseal seal plate cover to the seal housing and remove the cover.

3)Remove the screws securing the Rheoseal seal housing to the cover plate and withdraw the housing from the cover plate and shaft, taking care not to dam- age the drive shaft. After removal of the seal housing, disassemble and clean the Rheoseal housings either mechanically or chemically (always replace the O-rings).

4)Carefully pry out and discard the lipseals at this time, taking care not to damage the seal countersink in the hous- ing, as damage here could cause polymer leakage at start-up.

5)Loosen and remove the D-bearing retainer screws (40 cc/rev and above only).

6)Loosen all cover plate screws one turn, then back them out and remove them from the pump. Remove each cover

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