4 replies to this topic

[irprocess]

Dear All,

Following recycled lines which commonly used in process plants for pumps:

• The orificed bypass,
• The control valve in bypass line
• A combination check valve/bypass valve.

Can anyone tell me preferred criteria (flowrate, power) for above-mentioned items.

Any help is much appreciated.

[ankur2061]

irprocess,

A very interesting discussion related to control valve in the recylce or minimum flow line can be viewed at:

http://www.cheresour...1110#entry21110

Additionally some very good schemes for minimum recylce flow are shown in the article whose link is given below:

http://www.chemicalp...s/2007/109.html

Another nice article related to minimum continuous flow can be found at:

http://www.lawrencep...vol3_i1_jan.pdf

Hope this helps.

Regards,
Ankur.

[irprocess]

Dear Ankur,

Thanks for your swift reply.

I see all of mentioned links , but for your information; in EXXONMOBIL's design practices for pump (installation facilities) is referred to power of pump ( recommended orifice for below 38 kw and above it to use control valve) ,I want to know is there any recommendation in your side for using each of them ?

[ankur2061]

irprocess,

There are some very economical solutions for control valves in the minimum recylce flow line. A very economical and effective solution would be to provide a "Yarway" automatic recirculation valve. I have seen these in operation in the minimum recycle line of large capacity Boiler Feed Water centrifugal pumps and they work fine. The link below provides information about the Yarway automatic recirculation valve.

http://www.mento.no/...les.php?sub=242

Hope this helps.

Regards,
Ankur.

[fallah]

Dear Ankur,

Thanks for your swift reply.

I see all of mentioned links , but for your information; in EXXONMOBIL's design practices for pump (installation facilities) is referred to power of pump ( recommended orifice for below 38 kw and above it to use control valve) ,I want to know is there any recommendation in your side for using each of them ?

irprocess,

In some reputable companies practices, up to 15 KW installed power it is preferred to have a permanent recirculation line fitted with an orifice as minimum flow line of pump protection.

Fallah