Is my low pressure reservoir defined as a pressure vessel? 4

[psarandy]

I have a sealed, water cooled stainless steel cylindrical bowl (2 ft diameter by 4in tall) with water free-flowing through it at 60psi and (0-30ºC) and exiting out at room temperature. The overall temperature of the bowl does not exceed 50ºC and there are NO internal valves used to build up pressure.

With the 60psi input, is this defined to be a pressure vessel? Anyone have any links or readings that can assist me in determining this?

 

[MJCronin]

Nope....(in my opinion)

In general, to qualify as an ASME pressure vessel, the device must operate at 15 psig (or greater) have a certain minimum volume and some other requirements.

If the device cannot physically get to 15 psig or greater....it is something else.

-MJC

 

[zdas04]

If it has a block valve on the outlet or if the outlet pipe might be subject to freezing then you do have to have overpressure protection (more than 6-inches ID and can be pressureized to greater than 15 psig).

David

 

[metengr]

Just check with your Jurisdiction that regulates pressure vessels where this reservoir will be installed. You may find that the vessels used in water systems are exempt as pressure vessels. You may still want to install some type of waterside relief device, but it would not be required by Code.

 

[jte]

Not enough info to make a stronger judgment, but I find myself leaning towards “not a vessel” as well. See ASME B&PV Code Section VIII Div. 1 U(1)(c)(2) for some exceptions which would place you out of its scope. However… keep in mind that just because you meet one or more exceptions which places you out of the scope doesn’t mean you can’t build it and U stamp it if you choose. Seems to me your “bowl” might fall under at least two exceptions:

(f) a vessel for containing water under pressure, including those containing air the compression of which serves only as a cushion, when none of the following limitations are exceeded:
(1) a design pressure of 300 psi (2 MPa);
(2) a design temperature of 210°F (99°C);

(i) vessels having an inside diameter, width, height, or cross section diagonal not exceeding 6 in. (152 mm), with no limitation on length of vessel or pressure;

(Your 4” height gives you one dimension which is less than 6” so you (dis)qualify regardless of diameter.)

But, as metengr noted, checking with the local jurisdiction where the device will be installed never hurts!

jt