RELATIVE DENSITY
3.49 relative density or specific gravity
Property of a liquid expressed as the ratio of the liquid’s density to that of water at standard temperature. {API 610}
NOTE Standard temperature is 4 °C (39,2 °F).
6.3.9 Unless otherwise specified, pumps with radially split casings are required in services for any of the
following operating conditions: {API 610}
- pumping temperature of 200 °C (400 °F) or higher (a lower temperature limit should be considered if thermal shock is probable);
- liquids with a relative density of less than 0,7 at the specified pumping temperature;
- liquids at a rated discharge gauge pressure above 10 MPa (100 bar; 1 450 psi).
8.3.2.7 The hydrostatic test liquid shall include a wetting agent to reduce surface tension if one or more of the
following conditions exists. {API 610}
- The liquid pumped has a relative density (specific gravity) of less than 0,7 at the pumping temperature.
- The pumping temperature is higher than 260 °C (500 °F).
- The casing is cast from a new or altered pattern.
- The materials are known to have poor castability.
- (The pump casing is axially split and the liquid pumped has a relative density less than 0.8 at the pumping temperature. {just this item belongs to Bid Boland})
6.3.1 The maximum discharge pressure shall be the maximum suction pressure plus the maximum differential pressure that the pump is able to develop when operating with the furnished impeller at the rated speed and specified normal relative density (specific gravity). {API 610}
NOTE The basis of determining maximum discharge pressure is an application issue. {API 610}
6.3.2 Maximum discharge pressure shall be stated on the data sheet. If specified, the maximum discharge pressure shall be increased by the additional differential pressure developed during one or more of the following operating circumstances: {API 610}
- maximum specified relative density at any specified operating condition;
- installation of an impeller of the maximum diameter and/or number of stages that the pump can accommodate.
- operation to trip speed.
Comments: