Published "standards/best practices" in way of Screw Pumps & pipin 3

[Zylinderkopf]

Season's Greetings, fellow Engineers:

As static equipment has been my career "bayliwick", I will remain most grateful for your guidance in way of the subject matter.

I am considering installation of screw-type pumps for a lube oil system. It seems that I have incorrectly presumed that there exists published standards for screw-type pumps and the dedicated piping, not unlike API 610, WRC 449 and like standards published by the Hyrdaulic Institute utilized with Centrifugal-type pumps.

I am especially concerned about the best design practice(s) for piping installation in way of the Screw-type pumps' PRV's.

I suppose that I will ultimately rely on the information contained in the standards that I have referenced above, such that I will employ these standards with Screw-type pumps; however, "something just doesn't feel right to me" by using this approach.

Any assistance that any of you afford me will never be taken for granted and will always be appreciated.

Thank you for your time and kind consideration of my enquiry.

Pete

 

[saxon69]

I work for a Screw pump company. API 676 is the only "standard" that I typically see referenced.

As far as PRV's go....always direct them back to the tank, not directly to the suction of the pump.

 

[Zylinderkopf]

Greetings, "Saxon69":

Please accept a "star" for youf kind referral to API 676; thank you also for your direction in way of PRV discharge routing.

Thank you for your kind conisderation of my enquiry and Happy New Year!

 

[Cheddarcaveman]

Another thing to bear in mind is that, should the PRV jam or stick for whatever reason, the discharge piping MUST be able to withstand well above "normal" operating pressures. In some circumstances it may also be prudent to install two PRVs. Lube oil is not too much of problem should it leak as it just makes a mess!

 

[khardy]

As for “best practices” I can recommend the following link to IMO Pumps:

http://www.imo-pump.com/tech.htm.

IMO is one of the largest manufacturers of screw pumps. (On at least one of those documents there is a picture of a pump station my company installed.)


As for pressure relief: many PD pumps either have, or can be ordered with, their own integral pressure relief valve. These valves are usually meant for emergency relief and if one should relieve against a dead head the pump will eventually overheat if it isn’t shut down. As insurance against this it is also a good idea to install a temp probe / switch on the pump which will cut out power should the temperature get to high. As stated previously, it does not hurt to supplement the pump's own internal PRV valve with an external one set at a lower pressure. The outlet of this valve should run as far back to the suction side as possible so as to dissipate heat. If possible run it all the way back to the suction side reservoir.

 

[Zylinderkopf]

Greetings, "Cheddarcaveman":

Please accept a "star" for your direction in way of piping design for the subject application.

Thank you for your time and consideration of my enquiry.

 

[Zylinderkopf]

Greetings, "khardy":

Please accept a "star" for your kind referral to the IMO Pumps web link. Thank you also for your advise in way of relief system design.

Thank you for your time and consideration of my enquiry.