Changing pump rotation – Viking Pump TSM685.1: GS-HL 855 User Manual

Page 10

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SECTION TSM

685.1

ISSUE

PAGE 10 OF 16

Do not attempt to reuse a PTFE (derivative) encapsulated

O-ring if it has been removed. Immerse a new O-ring in

boiling water for a few minutes. Remove it from the water

and stretch out the O-ring so it will fit onto the casing hub

without forcing it over a sharp edge. Run hot water* over

the O-ring until it shrinks down tight onto the pilot of the

pump. Dry with compressed air.

2. Clean the rotor and shaft so it is free of dirt, grit and other

debris and apply lubricant. Place one thrust washer onto

shaft so that the blind hole in thrust washer will line up

with the drive pin on back of rotor. Push it into the casing

as far as it will go.

3. Slide the second thrust washer onto the shaft, drive hole

facing out and then install key into the shaft.

4. Slide the inner magnet onto the shaft and engage the pin

of magnet into hole of thrust washer. Install the locknut,

beveled edge out, set torque to measurements given in

Table 5. Place a mark on the trailing edge of the locknut

slot. Refer to Figure 17. Back off the locknut until the

leading edge of that same slot lines up with the mark.

This will establish the proper clearance for the thrust

washers.

5. Place the set collar on the locknut and install the two

machine screws.

6. If the old metal shims are not reusable or if any parts have

been replaced, operating clearances will need to be re-

established. Refer to

ADjUSTING END CLEARANCE,

page 13. Otherwise, place the head shims on the head.

The proper amount of shims should be used to provide

the correct end clearance. Table 6 gives the quantity of

shims available in a gasket set along with standard end

clearance.

7. Coat the idler pin with a suitable lubricant and place the

idler on the idler pin in head. Make sure the O-ring for the

head is installed.

8. The head can now be assembled onto the pump. Tilt the

top of the pump head away from the pump slightly until

the crescent enters the inside diameter of the rotor and

rotate the idler until its teeth mesh with the rotor teeth.

The pump head and casing should have been marked

before disassembly to insure proper reassembly. If not,

be sure the idler pin, which is offset in the pump head,

is positioned toward and an equal distance from the port

connections to allow for proper flow of liquid through the

pump. Install the head capscrews. Rotate the shaft to

make sure it turns freely.

9. Follow the instructions listed for assembling the

appropriate size coupling on pages 11 and 12.

CHANGING PUMP ROTATION

The pump is designed to operate in either direction. Process

fluid is generally fed to the inner thrust washer and bushing

interface and then through a groove in the bushing to the

outer thrust washer. Then the fluid is pulled into the canister

bushing and back through the hollow shaft and idler pin to the

suction side of the pump. When the pump is operated in the

opposite direction, the fluid flow is reversed.

NORMAL

END

CLEARANCE

SET Of HEAD

Shims INCLUDES

GS, GG 855

0.003

(1) .007
(1) .005
(2) .002
(2) .001

HJ, HL 855

0.005

End Clearances are adequate for viscosities up to 2500 SSU / 540

cSt (SAE 40 lube oil at room temperature). Higher viscosities require

additional clearances. As a general rule the end clearance is doubled

for higher viscosities. For specific recommendations for end clearance

for viscosity or for operating temperatures above 225°F, check with your

Viking representative or consult the factory.

TABLE 6

fIGURE 18

fIGURE 17

Mark

Leading Edge of

Locknut

*Hot water makes the PTFE® more pliable and allows the inner elastomer to

pull the PTFE back to the orginal size.

Locknut Torque Requirement

In-Lbs

N-m

MD2-A

2.8

MD2-B

6.8

TABLE 5

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