Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)
Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)
(OP)
I was wondering if anyone had experience with ASME Section VIII Div 1 UG-135 (b)(1) and the minimum required pipe/fitting area between an ASME Section VIII Vessel and its thermal relief valve. UG-135 (b)(1) states:
The opening through all pipe, fittings and nonreclosing pressure relief device (if installed) between a pressure vessel and its pressure relief valve shall have at least the area of the pressure relief valve inlet.
The existing configuration that its being investigated is a short NPS 1/2 SCH 40 pipe (welded to the pressure vessel), 1/2"x3/4" NPT reducer and a 3/4"x1" NPT relief valve. The question around UG-135 (b)(1) is what the "area of the pressure relief valve inlet" refers to? Does this mean the relief valve should be no greater than a 1/2" inlet like NPS 1/2 SCH tank pipe? Or is this relief valve inlet area referring to the relief valve orifice diameter?
Thanks
The opening through all pipe, fittings and nonreclosing pressure relief device (if installed) between a pressure vessel and its pressure relief valve shall have at least the area of the pressure relief valve inlet.
The existing configuration that its being investigated is a short NPS 1/2 SCH 40 pipe (welded to the pressure vessel), 1/2"x3/4" NPT reducer and a 3/4"x1" NPT relief valve. The question around UG-135 (b)(1) is what the "area of the pressure relief valve inlet" refers to? Does this mean the relief valve should be no greater than a 1/2" inlet like NPS 1/2 SCH tank pipe? Or is this relief valve inlet area referring to the relief valve orifice diameter?
Thanks





RE: Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)
Extreme lengths (of either minimum diameter) pipe are not allowed either in suction or discharge of the relief valve. Intent being "Thou shalt never strangle flow to a closed Pressure Relief Valve, nor shalt thou ever prevent flow out of the an opened Pressure Relief Valve."
RE: Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)
Thanks again
RE: Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)
RE: Minimum Required inlet piping opening per ASME Section VIII Div 1 UG-135 (b)(1)