Pressure relief valve (PRV) installed where ?

[Suresh Thevan]

Hi

I am from the oil & gas industry manufacturing Lubricants. I will like to know ,

1. Installing the PRV at the top of the Tank is right /good OR is it installing at the grade level better ? (Pros & Cons)
2. What codes or standards can I refer back to ? (It would be so great if you could share the standard name ,section , pg number)
3. To take my PRV out for servicing, i should have bleeders and block valves installed OR not necessarily ?

 

[The Obturator]

Hi. Please note there is a separate forum for safety relief valves. But I'll provide some commentary here.
1. Dependant on fluid and vessel design, top mounting is generally the done thing. Need to know more before stating pros and cons. eg., what is PRV required for? (external fire, blocked outlet), whether vessel is liquid filled (amount liquid) etc., etc.
2. Good references can be found in API-521. Others will advise additional publications.
3. It is recommended to use Changeover Valves. These will allow plant to run uninterrupted. However, you need to double up on the amount of PRV's. Some PRV manufacturers provide changeover valves. Other schemes are available with their pros and cons.

Per ISO-4126, only the term Safety Valve is used regardless of application or design.

 

[mk3223]

Also for reference, check API-2000 for the normal and emergency venting requirements of the storage tank service.