Mechanical run test

[fe2655847]

API 610 para 7.3.4.7.1 states that pump, if specified, shall be run on the test stand until oil temperature stabilization has been achieved. Is VS4/VS5 grease-lubricated pump covered in the statement?Is "grease" covered in the word "oil" in the paragraph?I think grease and oil are different.

Thank you.

 

[JJPellin]

Grease is composed of oil plus thickener. Thickener does not lubricate the bearing. The bearing is lubricated with oil.

It says "if specified." If you want this test requirement, specify it. If you do not want it, do not specify.

For grease lubricated ball bearings, I would not specify this requirement


Johnny Pellin

 

[bimr]

Grease is not covered. Grease is used to describe semisolid lubricants.

Oil viscosity changes with temperature. When temperature rises, an oil becomes less viscous. Hence, the temperature must be specified whenever a certain viscosity of a liquid is required.

 

[Pumpsonly]

The extended mechanical run test is to check bearing loading is not excessive. Over loaded bearing will have temperature keep on rising.
During mechanical run test,the oil temperature or the bearing housing temperature for grease lubricated bearing are recorded at a fixed time interval. A Temperature Vs Time graph is plotted until the graph goes flat.. indicating the temp. has stabilised.i.e heat generated = heat dissipated.
The temp. rise over the ambient temp will be checked if it is within the limit specified.
Grease temp. is not mentioned because para 5.11.1 states, "unless otherwise specified, bearings and bearing housing shall be designed for oil lubrication...."