Performance - Johnson Pump SPX FLOW TopGear GS Instruction Manual

2.0 Performance

• Operation of the pump outside its specified operating range and unauthorised modes
of operation may result in the specified temperature limits being exceeded. See IM for
temperature limits.
• In order to remove the heat generated by hydraulic and mechanical friction inside the
pump, it must be assured that there is always a sufficient minimum flow through the
pump. If this cannot be ensured under all possible operating conditions or because
the conditions might change over time due to wear, we advise to foresee a suitable
temperature monitoring device. (See chapter 1.9)
Note: Internally produced friction heat depends of pump speed and of the properties of
the pumped media: viscosity, specific heat, lubricating properties etc.
It is the responsibility of the operator to ensure the pump operates below the allowable
temperature limits as indicated above.
Dangerous situations can occur in the following events and should be
prevented and/or excluded from normal operation and expected operation
(group II-category 2) by adequate operation, supervising and maintenance:
• Running the pump without liquid will produce extra heat in the sleeve bearings and on
other friction sensitive parts. Temperature can rise above allowable limits as a result
of insufficient lubrication and/or lack of heat expulsion through liquid flow. Insufficient
lubrication can cause preliminary pump wear and failure.
• Heat accumulation can be caused by direct return of liquid from discharge side to
suction side of the pump.
The pump temperature could increase above allowable limit when the pump is operating
with the relief valve opened for a length of time or during flow control when by-passing
the medium to the suction side of the pump.
• Increase of internal slip by internal wear in such a way that the output flow rate will
become insufficient to evacuate the internal friction heat. Temperature could increase
above allowable limit.
• Monitoring of the surface temperatures of the pump casing at indicated areas (see fig.
1 and 2) and controlling or monitoring the quench medium in case of a quenched shaft
seal ensures sufficient protection against potentially dangerous situations.
14
A.0500.601 – Atex IM -TG G/H/MAG/SRT/08.00 EN (01/2021)