Certifications for Tanks PSVs

[Sawsan311]

Dear All,

I would like to ask whether API 650 tanks have their PSVs designed in accordance with API 526. I am aware that API 2000 is the standard used for tank's normal outbreathing as well as emergency venting requirements calculations for sizing emergency vents and blow out hatch.However, do tank vendors use API 526 orifice designation for their valves ( I have seen none of the vendors consider that). Additionally, do these tank PSVs have ASME capacity certification requirements even if the tank is not a pressure vessel belonging to ASME SEC VIII.

Thanks

 

[RVAmeche]

Atmospheric or low pressure tanks do not typically use PSVs because of the higher pressure set points, typically 15 psig and above but sometimes manufacturer's will supply set pressures less than 15 psig with no ASME stamp, since it is outside of ASME's scope.

Atmospheric tanks simply require normal and emergency venting in accordance with API 2000 and there are many manufacturer's that design vents in accordance with that standard. These vents do not use the API 526 orifices because they're completely unrelated devices.

 

[MJCronin]

The API-650 tank design rules are for tanks designed to a maximum of 2.5 psig

API-620 tanks can be designed for tanks to a somewhat higher pressure, but less than 15 psig

What are the design codes for your tanks and what is their design pressures ???

MJCronin
Sr. Process Engineer