Viking Pump TSM680: 895, 893 and 897 Mag Drive - Manual (Page 16)

SECTION TSM 680 ISSUE G PAGE 16 OF 17
DANGER!
before starting pump, be sure all drive equip-
ment guards are in place.
Failure to properly mount guards may result in
serious injury or death.
PRESSURE ADJUSTMENT
If a new spring is installed or if the pressure setting of
pressure relief valve is to be changed from that which the
factory has set, the following instructions must be carefully
followed.
1. Carefully remove the valve cap, which covers adjusting
screw.
2. Loosen the locknut, which locks the adjusting screw so
pressure setting will not change during operation of
pump.
3. Install a pressure gauge in the discharge line for actual
adjustment operation.
4. Turn the adjusting screw in to increase pressure and out
to decrease pressure.
5. With discharge line closed at a point beyond pressure
gauge, gauge will show the maximum pressure valve will
allow while the pump is in operation.
IMPORTANT
In ordering parts for pressure relief valve, always give
model number and serial number of pump as it appears on
nameplate and name of part wanted. When ordering springs,
be sure to give pressure setting desired.
VALVE - LIST OF PARTS
1. Valve Cap 6. Valve Body
2. Adjusting Screw 7. Valve Spring
3. Lock Nut 8. Poppet
4. Spring Guide 9. Cap Gasket
5. Bonnet 10. Bonnet Gasket
VALVE – AS, Ak AND AL SIZES
FIGURE 44
TROUbLESHOOTING
Some of the following may help pinpoint the problem:
Pump does not pump:
•
Pump has lost its prime from air leak or low level in tank.
• Suction lift is too high.
• Pump is rotating in the wrong direction.
• The strainer may be clogged.
• The bypass valve is open, the pressure relief valve is set
too low or the pressure relief valve poppet is stuck open.
• Improper end clearance.
• The pump is worn out.
• Are there any changes in liquid, system or operation that
would influence pump or coupling performance, e.g. new
liquid, additional lines or process changes?
• Temperature changes either in the liquid or the
environment.
• The magnetic coupling is decoupling. Changes in
application (temperature, pressure, viscosity, etc.) may
require torque beyond coupling capabilities.
Pump starts, then loses its prime:
•
The supply tank is empty.
• Liquid is vaporizing in the suction line.
• An air leak or air pocket in the suction line.
Pump is noisy:
•
The pump is being starved (heavy liquid cannot get
to pump fast enough). Increase the suction pipe size,
reduce its length or slow down the pump.
• The pump is cavitating (liquid vaporizing in suction line).
Increase suction pipe size or reduce its length.
• Check alignment.
• The magnetic coupling has decoupled. Shut off and
restart.
Pump is not delivering up to capacity:
•
The pump is starving or cavitating - increase suction
pipe size or reduce length or reduce pump speed.
• The strainer is partially clogged.
• An air leak somewhere in suction line.
• The pump may be running too slow. Is motor the correct
speed and wired up correctly ?
• The pressure relief valve is set too low, stuck open or
has a damaged poppet or seat.
• The bypass line around the pump is partially open.
• The pump is worn out or there is too much end clearance.
Pump takes too much power (stalls motor):
• The liquid is more viscous than the unit is sized to
handle.
• The system pressure relief valve is set too high.
• The bushings have frozen up or the liquid has set up in
the pump.