Viking Pump TSM350 HG-08/HG-10 Helical Gear Pumps - Manual (Page 8)

SECTION TSM 350 ISSUE A PAGE 8 OF 10
MISCELLANEOUS
Pump does not pump:
1. The pump has lost its prime from air leak or low level in tank.
2. The suction lift is too high.
3. Rotating in the wrong direction.
4. The motor does not come up to speed.
5. The strainer is clogged.
6. The bypass valve is open, pressure relief valve set too low or pressure relief valve poppet
stuck open.
7. The pump is worn out.
8. Any changes in liquid, system or operation that would help explain the trouble, e.g. new
liquid, additional lines or process changes.
Pump starts, then loses its prime:
1. The supply tank is empty.
2. The liquid is vaporizing in the suction line.
3. There is an air leak or air pockets in the suction line.
4. The pump is worn out.
P ump is noisy:
1. The pump is cavitating (liquid vaporizing in suction line) or being starved (heavy liquid
cannot get to pump fast enough). Increase the suction pipe size and/or reduce the length,
or decrease the pump speed. If the pump is above the liquid, raise the liquid level closer
to the center line of the inlet port. If the liquid is above the pump, increase the head of the
liquid.
2. Check alignment.
3. Anchor the base or piping to eliminate vibration.
Pump not delivering up to capacity:
1. The pump is starving or cavitating – see Pump is noisy, item 1.
2. The strainer partially clogged.
3. Air leak somewhere in the suction line.
4. Running too slow. Is the motor the correct speed and wired up correctly?
5. Pressure relief valve is set too low, stuck open or has damaged poppet seat.
6. The bypass line around the pump partially opened.
7. The pump is worn out.
Pump takes too much power (stalls motor):
1. Liquid is more viscous than the unit is sized to handle.
2. The system pressure relief valve set too high.
3. The pump is misaligned.