475 Series™ Mechanical Seal Pumps; (G, Gg Size) - Viking pump 75 Series Technical & Service Manual

TABLE 2: GASKET TABLE (H, HJ, HL SIZE)
Normal
Pump Model Amount Used
H75, HJ75, HL75 .010" - .015"
6. A small screw (self-locking) is inserted in a hole on the
discharge side of the pump. This can be seen through
the port opening and behind the rotor (refer to "Figure 7"
on page 6). The hole on the suction side must be left
open to prevent damage to the lip seals.
7. The head can now be assembled on the pump. Tilt
the top of the 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. Do not
damage the head gaskets. Note the correct position of the
idler and crescent. (See "Figure 8" on page 6 and
"Pump Disassembly" on page 5 Step 2). Tighten the
head capscrews and then check the end clearance.
8. Check pump end clearance. Measure the clearance
between the back of the rotor and the machined surface
in the bottom of the casing by inserting a feeler gauge
through the port opening. This is the end clearance.
Normal amount is 0.003" to 0.005". Add or remove gaskets
until the figure is reached.
9. Bolt the valve to the casing. Place the valve gasket and
valve or coverplate on the pump and fasten securely with
the four capscrews.
⚠ CAUTION !
Be sure the adjusting screw of the relief valve points
toward the suction port.
10. Assemble the pump on the motor. Install the full length
key in the keyway of the motor shaft.
NOTE: Key must be full length to avoid misalignment of
the pump rotor, which could cause serious damage to
the pump. Slide the pump on the motor shaft and fasten
securely with the four capscrews.
475 SERIES™ MECHANICAL SEAL
PUMPS (G, GG SIZE)
See "Figure 9" on page 7
1. Install the rotor in the casing.
2. Install the idler. Put the idler with bushing on the idler pin.
3. Place the head gasket on the head. The proper amount
of gaskets should be used to provide the necessary
end clearance within the pump so it turns freely with no
appreciable end play. "Table 3" on page 7 gives the
normal amount of gaskets used.
TABLE 3: GASKET TABLE (G, GG SIZE)
Normal
Pump Model Amount Used
G475, GG475 .010" - .015"
© 2019 Viking Pump, Inc. • Cedar Falls, IA
One Set of Gaskets
Consists of the Following
2 - .002" Plastic
2 - .006" Paper
One Set of Gaskets
Consists of the Following
2 - .005" Plastic
3 - .002" Plastic
FIGURE 9: 475 SERIES™ MECHANICAL SEAL PUMPS

(G, GG SIZE)

Seal Spring Washer
Rotor
Idler
Head
Member
Seal Seat
Crescent
4. Two small screws (self-locking) are inserted in holes on
the suction and discharge sides of the pump. This can be
seen through the port opening and behind the rotor (refer
to "Figure 7" on page 6).
5. The head can now be assembled on the pump. Tilt
the top of the 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. Do not
damage the head gaskets.
Note the correct position of the idler and crescent
(See "Figure 9" on page 7 and refer to "Pump
Disassembly" on page 5 Step 2). Tighten the head
capscrews and then check the end clearance.
6. Check the pump end clearance. Measure the clearance
between the back of the rotor and the machined surface
in the bottom of the casing by inserting the feeler gauge
through the port opening. This is the end clearance.
Normal amount is 0.003" to 0.005". Add or remove gaskets
until the figure is reached.
7. Install the mechanical seal. Slide the seal spring
washer over the rotor hub as far as it will go. Flush the
rotor hub and seal housing bore with light oil (not grease)
and assemble the spring, rotary member and seat of the
mechanical seal in position, see "Figure 9" on page 7.
⚠
CAUTION !
Never touch the sealing faces of the mechanical seal with
anything except fingers or a clean cloth.
8. Install the snap ring. Install the snap ring in the groove in
the casing. This will hold the seal at its proper working length.
9. Bolt the valve to the casing. Place the valve gasket and
valve or coverplate on the pump and fasten securely with
the four capscrews.
TSM 1445 | Issue A | Page 7 of 18
Mounting Flange
Snap
Ring
Spring
Rotary