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Installation
■ Suction line
•
Avoid any loops in a plumbing run that could form a vapour trap. A
suction line should be laid on a rising gradient of 1/100 toward the
pump so as to expel air easily.
Suction line examples
Acceptable
Unacceptable
•
In order to minimize plumbing resistance, have plumbing shortest
with the minimum bends. Note cavitation*¹ tends to occur when
plumbing length is too long.
•
A liquid level should be at least 30cm higher than the tank outlet for
the prevention of air ingress.
•
Keep liquid in the supply tank free from foreign matters. Clean the
supply tank at intervals.
•
Be sure to secure connections on a suction line for the prevention
of entrained air. The presence of air in a suction line may prevent
liquid delivery.
■ Discharge line
•
Piping resistance changes with properties of liquid, specific gravity,
liquid temperature and pipe length, and may adversely affect pump
operation when the resistance is too great. In order to minimize the
piping resistance, have piping length shortest with the minimum
bends. Contact us for detail.
•
When a discharge line is too long, water hammer*² phenomenon
may occur and damage the pump with impact pressure when the
pump stops running. Provide a check valve to prevent water ham-
mer.
Word & Terms:
*1 Air bubbles caused by a negative pressure in the pump, accompanied with vibration and
noise: Performance deterioration or parts corrosion results.
*2 Shutting off a discharge line at once, liquid pressure change causes an impact pressure,
accompanying impact noise and vibration. This phenomenon is called water hammer.
Water hammer damages the pump & pipework and may cause leakage.
Ascending gradient
Descending gradient
U-shaped piping
Arched piping
Air trap
Flooded suction
Suction lift