Johnson Pump TG GS2-25 - Page 41

41
A.0500.501 – IM-TGGS/05.01 EN (03/2013)
Symptom Cause Remedy
Not enough capacity Viscosity too low 17 • Increase pump speed. Attention! Do not exceed
maximum speed and check NPSHr.
• If necessary, install a larger pump.
• If pump is heated by means of heating jackets or
electrical heating, reduce the heating input.
Axial clearance 18 • Check axial clearance and correct.
See section 3.21 Maintenance instructions.
Gases come free 19 • Increase pump speed. Attention! Do not exceed
maximum speed and check NPSHr.
• Install a larger pump
Pump too noisy Pump speed too high 20 • Reduce pump speed.
If necessary, install a larger pump.
Cavitation 21 • Reduce difference between pump and suction
tank level.
• Increase suction pipe diameter.
• Reduce length and simplify suction pipe (use as
few elbows and other fittings as possible).
Also see section 3.18 Installation.
Back pressure too high 22 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.).
Coupling misalignment 23 • Check and correct alignment.
Also see section 3.18 Installation.
Vibration of base plate or pipings 24 • Make baseplate heavier and/or fix base plate/
pipework better.
Ball bearings damaged or worn 25 • Replace ball bearings.
Pump consumes
too much power or
becomes hot
Pump speed too high 26 • Reduce pump speed.
If necessary, install a larger pump.
Coupling misalignment 27 • Check and correct alignment.
Also see section 3.18 Installation.
Viscosity too high 28 • Increase axial clearance.
See section 3.21 Maintenance instructions.
• Heat pump.
• Reduce pump speed.
• Increase discharge pipe diameter.
Rapid wear Back pressure too high 29 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.)
Solid matter in liquid 30 • Filter liquid.
Pump runs dry 31 • Correct liquid supply.
• Provide level switch or dry running protection.
• Heat up liquid.
• Stop or reduce air sucking.
Corrosion 32 • Change pump materials or application
parameters.
Motor overloading Back pressure too high 33 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.).
Viscosity too high 34 • Increase axial clearance.
See section 3.21 Maintenance instructions.
• Heat pump.
• Reduce pump speed.
• Increase discharge pipe diameter.
Pump leak Mechanical seal leaks 35 • Replace mechanical seal.