The issue of pump type selection
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This post was last edited by majing*an on 2010-9-21 at 11:48. There is a current case to discuss regarding selection issues. Medium: methanol; Temperature: -60 degrees Celsius; Inlet pressure: 3 barG; Head: 50 m; Flow rate: 560 m3/h. Depending on the load that the pump model can handle, OH2, BB1, and BB2 are all suitable options. For general high-flow applications, the BB pump type is preferred (BB1BB2 with a lower head is sufficient); cantilever pumps can also meet the requirements, but their design leads to relatively poorer stability. For the above operating conditions, BB1 seems sufficient, but looking at the applicable temperature ranges specified by some manufacturers, where temperatures are below minus 40 degrees Celsius, BB2 is chosen; its pressure rating is certainly higher than that of BB1. In terms of cost, the individual estimates, from lowest to highest, are OH2, BB1, BB2. Question: When it comes to specific operating conditions, how should one choose the pump type? Everyone can share their own experience of use – for example, at what data volume level should a BB pump type be chosen, and within what temperature range should different types of pumps be used (taking into account that even among manufacturers, the performance of pumps of the same type can vary; it is therefore possible to compare the advantages and disadvantages of different pump types on an equal footing)
Recently, this issue also arose in technical negotiations; the choice of type BB1 was mainly due to insufficient single-suction net positive suction head, so it was changed to double-suction BB1
Cavitation is a very important issue in this context; I hope there is an accurate answer.
OH2 type centrifugal pumps are also an option and are cost-effective, but it is essential to choose proven API pumps. Some unreputable domestic pump manufacturers fake API pumps by modifying them; such pumps fail to meet the required standards and can easily cause high vibration. Try not to choose OH2 pumps that are located near the boundaries of the performance spectrum; the BB2 type could be considered instead. Manufacturers generally opt for OH2 pumps in order to keep costs low, so purchasers need to think this through carefully.