Definition of pressure vessel according to ASME

[PDXMech]

This is my very first post in this professional forum. Is tubular shaped pressure accumulator, sized 80mm(3.15") ID and 1.5L(0.053 cubic foot) in volume with 350bar(5075psi) pressure, considered as pressure vessel according to ASME? Reason I'm asking is that it is well below diameter of 6", but in the other hand it's storing gas and doesn't transport it anywhere (like pipe line), which should put it in the pressure vessel category. Thanks for your answers!

 

[bernoullies123]

ASME considers a pressure vessel when the pressure is greater than 15 psi.

 

[JStephen]

Per ASME Section VIII, pressure vessels are "containers for the containment of pressure", so your vessel, along with a lot of other miscellaneous containers would fit that definition (ie, soda bottles, CO2 cartridges, car tires.) However, that doesn't mean it's regulated by Section VIII, which exempts vessels smaller than 6" diameter "with no limitation on pressure".

 

[vpl]

I agree with JStephen. It's excluded under the ASME VIII definition of Pressure Vessel. Specifically U-1(c)(2) states: Based on the Committee's consideration, the following classes of vessels are not included in the scope of this Division; however, any pressure vessel which meets all the applicable requirements of this Division may be stamped with the Certification Mark with the U Designator:

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.

Please see FAQ731-376

 

[moltenmetal]

A 24" pipe connecting two vessels and relieved above 15 psig isn't a vessel either- it's a piece of pressure piping, designed and fabricated per a piping code. Many local pressure equipment regulations exempt items such as domestic hot water storage tanks, hydraulic cylinders and expansion tanks (i.e. a type of accumulator) which would otherwise fall under section VIII. Check your local regs.

 

[JStephen]

Note that Section VIII itself exempts piping, domestic hot water tanks, hydraulic cylinders, etc.