Viking Pump TSM685.1: GS-HL 855 - Manual (Page 10)

SECTION TSM 685.1 ISSUE G 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 1
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
1 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 25 2.8
MD2-B 60 6.8
TABLE 5