|
Parameter |
ANSI / ASME Pump |
API Pump |
|
Type & Specification |
ASME B73.1 Horizontal End Suction Centrifugal Pumps ASME B73.2 Vertical In-Line Centrifugal Pumps |
API STD 610 (ISO 13709:2009) Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries |
|
Max. Allowable Working Pressure (MAWP) |
275 psig |
Min. 700 psig, some API Pumps are designed for pressure above 5,000 psig |
|
Hydrostatic Pressure |
415 psig |
Min. 1,050 psig. API Pump hydrostatic test pressure will be 1.5 times the MAWP |
|
Flange Rating |
150# FF is standard, 150# RF is available. |
300# RF is standard. 600#, 900#, 1500#, and higher ratings are available if required by the service. |
|
Max. Temperature |
250 oF Pump casing is foot mounted which limits allowable thermal growth. |
800 oF Pump casing is centerline mounted. No casing thermal growth limitations. |
|
Material (Casing & Impeller) |
Ductile Iron, 316 SS, Alloy 20. Carbon Steel casing or impeller is not commonly available. |
Carbon Steel casing is standard, Stainless Steel is also available. Impeller materials are cast iron, carbon steel, stainless steel. |
|
Max. Head Differential |
550 to 600 ft ANSI pumps are only single stage, max. impeller diameter is about 13 in. |
Practical limit is 10,000 ft. Horizontal API Pumps can have as many as 14 stages. |
|
Impeller Design & Attachment |
Open impellers are common, but some enclosed impellers are available. No standard for attachment to the shaft, and most are threaded on the end of the shaft. |
All are enclosed design. Some open designs are available for special coke crushing services. Impellers must be key driven with a lock nut attachment. |
|
Standard Dimensions |
ANSI pumps are built for interchange-ability between manufacturers. |
No standard dimensions apply. |
|
Shaft Sleeves |
Not required but are available . Fit to the shaft and extension past the gland are not ANSI specification requirements. |
Are required to prevent shaft damage in the seal or packing area. Sleeve and stuffing box design is part of the API 610 specification. |
|
Lubrication |
Can be greased or oil lubricated. |
Oil lubrication is required. Usually ring oil system is provided. |
|
Thrust Bearing & Life |
Anti friction bearing only. B-10 bearing life of 17,500 hours at design load required. |
Antifriction ball bearing must be duplex, single row, 40 degree angular contact type, installed back to back. L-10 bearing life must exceed 25,000 hours at rated conditions, or 16,000 hours at max. axial & radial load at rated speed. |
|
Wear Rings |
Not required and not available in most designs due to the use of open impellers. |
Case and impeller, front and back wear wings are required. Wear ring clearances, attachment, and hardness differential are specified. |
