4 replies to this topic

[aju_1807]

Hi all,

As per API521 table-12, teh lateral (outlet line) sizing for modulating type pilot relief valve should be done based on required flow rate only and there is no mention of RV inlet line sizing for modulating pilot type relief valve. As per my understanding, the construction and functionailty of RV will not allow the RV to reach the rated capacity. Howeever, I dint find any convincing document which says that inlet line sizing should be also done based on required flow rate only.

appreciate some expert comments on this issue.

Regards,

aju

[fallah]

Hi all,

As per API521 table-12, teh lateral (outlet line) sizing for modulating type pilot relief valve should be done based on required flow rate only and there is no mention of RV inlet line sizing for modulating pilot type relief valve. As per my understanding, the construction and functionailty of RV will not allow the RV to reach the rated capacity. Howeever, I dint find any convincing document which says that inlet line sizing should be also done based on required flow rate only.

appreciate some expert comments on this issue.

Regards,

aju

Be sure,inlet line sizing calculation for modulating type of pilot operated valve should be done based on required flowrate.This can be seen in design manuals of some famous companies such as FLUOR Co.

[aju_1807]

Thanks fallah,

I worled with Bechtel in past and I know this guidelines are normally available as a corporate guideline in good companies but in other companies when we have to demonstrate this we cant rely on other company guieline.

If you know any other source then plwase let me know. I am checking with vendor in parallel.

Rgds

Aju

[CMA010]

Thanks fallah,

I worled with Bechtel in past and I know this guidelines are normally available as a corporate guideline in good companies but in other companies when we have to demonstrate this we cant rely on other company guieline.

If you know any other source then plwase let me know. I am checking with vendor in parallel.

Rgds

Aju

§4.2.3 of API RP 520, Sizing, Selection, and Installation of Pressure-relieving Devices in Refineries Part II - Installation?

[fallah]

Thanks fallah,

I worled with Bechtel in past and I know this guidelines are normally available as a corporate guideline in good companies but in other companies when we have to demonstrate this we cant rely on other company guieline.

If you know any other source then plwase let me know. I am checking with vendor in parallel.

Rgds

Aju

In my opinion,specified part (in red closed loop) of attached page indicates validity of using required relief load as a basis for inlet line sizing of modulating type PSV.

Please inform me about the result from checking with vendor.

Thanks

Attached Files

•  Pages from API 521.pdf   85.14KB   52 downloads

Edited by fallah, 15 February 2010 - 05:50 AM.