Is a throat bushing mandatory on API 610 Pumps
Is a throat bushing mandatory on API 610 Pumps
(OP)
Hi All, for a pump purchased according to API 610, is a throat bushing mandatory part of the design? Thanks in advance...
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Is a throat bushing mandatory on API 610 Pumps
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RE: Is a throat bushing mandatory on API 610 Pumps
RE: Is a throat bushing mandatory on API 610 Pumps
Based on this paragraph my understanding is that any pump purchased according to this specification shall have:
1. two casing/impeller wear rings
2. it should have throttle bushing...
Need your opinion...
RE: Is a throat bushing mandatory on API 610 Pumps
Para 5.7.1 only dictates certain design features for the wear rings. It does not dictate the number of wear rings or bushings. In certain circumstances such as high suction pressures with OH2 pumps, only one wear ring (on the impeller eye side) might be fitted to help balance axial thrust.
API 682 notes the optional nature of throat bushings in 6.1.2.15
BTW, the current edition of API 610 is 11th edition.
RE: Is a throat bushing mandatory on API 610 Pumps
RE: Is a throat bushing mandatory on API 610 Pumps
RE: Is a throat bushing mandatory on API 610 Pumps
With regard to the open impeller - technically API 610 does not refer to pumps equipped with open impellers - however, I did once purchased one such pump which was designed as per API 610 requierments with the stated exception of the impeller
RE: Is a throat bushing mandatory on API 610 Pumps
In addition to, if the pump will not be furnished by replaceable wear rings, it will be more costly to change the impeller. Thanks and hoping for additional comments.
RE: Is a throat bushing mandatory on API 610 Pumps
Previous versions of API 610 did not exclude the use of open impellers.
I don't agree that 5.7.1 10th edition precludes open impellers. All that paragraph limits is the use of close axial clearances. No reputable manufacturer is going to use close axial clearances on open impellers. For example we use a minimum axial clearance of 0.030" (0.75mm) per side on our OH2, OH3 open impellers, which is well in excess of what is necessary from a thermal transient standpoint.
RE: Is a throat bushing mandatory on API 610 Pumps
RE: Is a throat bushing mandatory on API 610 Pumps
I tend to agree that maintenance cost on closed impellers will be lower.
Open impeller pumps don't tend to play as well if there are any significant solids in the pumped fluid. When wear occurs, you are replacing larger more expensive components.
Please consider that the need for open impellers comes from the API 610 requirement to select a pump between 80 to 110% of BEP. For very low specific speeds, the only practical manufacturing option is an open impeller. As a manufacturer we will always offer a closed impeller where possible.
RE: Is a throat bushing mandatory on API 610 Pumps