HRSG Steam Drum - Design for Vacuum Conditions

[srinivasakumar]

For a HRSG Steam Drum, does ASME Section I, mandate vacuum design check? In other words, is it correct to say that all HRSG Boiler steam drums are required to be designed for full vacuum by ASME Section I?

Please be kind enough to reply.

 

[saplanti]

I guess you need to ask this to the process design engineer of the HRSG directly. From my experience HP drums do not require vacuum design but can handle full vacuum without any calculation. Depending on the process design again, LP drums might/may not involve with full vacuum. However, deaerators in HRSGs are designed for full vacuum and internal pressure.

I trust this is sufficient.

 

[srinivasakumar]

Dear Saplanti,
Many thanks for your response. My question was if Code mandated full vacuum design for the steam drums. I have gone through ASME Section I carefully, but could not find any requirement. Just wanted to be sure.

 

[saplanti]

Code is not written for specific process, therefore should not require anything like that. Everything is related to the process and its review.

 

[GenB]

Sect I is intended for positive pressure above 15 psi. So the answer to your question is NO.if you shall design for vacuum you may look at Sect VIII or if for std Hot water systems that work on vaccum principle use Sect IV.

General Blr. CA,USA

 

[srinivasakumar]

Thankyou GenB for the additional input.