B16.11 Hex Head Plug Pressure rating
B16.11 Hex Head Plug Pressure rating
(OP)
Designing a vessel to Section VIII Div. 1 and I need to calculate the pressure rating of this component.
It says in B16.11 that the pressure rating shall be computed as straight seamless pipe of equivalent material.Straight pipe MAWP is calulated in Section VIII Div.1 under UG-27 where it breaks it down to Circumferential Joint and Longitudinal Joint.
I'm having trouble calculating the Longitudinal Joint maximum allowable pressure rating. The formaula is:
P=2SEt/R-0.4t
E= joint efficiency = 0.70
S=max allowable stress = 14020psi
t= minimum required thickness of shell = 0.301in
R=inside radius of shell = 0.119in
The value for P im getting is -4,220,020psi because the thickness is a little bigger than the inside radius. The plug is a 1/2" hex head 3000# F316 - SA-182 so I chose 0.84in for the OD for the equivalent pipe. Am I missing something? I'm trying to get the MAWP for this plug component.
It says in B16.11 that the pressure rating shall be computed as straight seamless pipe of equivalent material.Straight pipe MAWP is calulated in Section VIII Div.1 under UG-27 where it breaks it down to Circumferential Joint and Longitudinal Joint.
I'm having trouble calculating the Longitudinal Joint maximum allowable pressure rating. The formaula is:
P=2SEt/R-0.4t
E= joint efficiency = 0.70
S=max allowable stress = 14020psi
t= minimum required thickness of shell = 0.301in
R=inside radius of shell = 0.119in
The value for P im getting is -4,220,020psi because the thickness is a little bigger than the inside radius. The plug is a 1/2" hex head 3000# F316 - SA-182 so I chose 0.84in for the OD for the equivalent pipe. Am I missing something? I'm trying to get the MAWP for this plug component.





RE: B16.11 Hex Head Plug Pressure rating
For the half coupling calculation I'd use the formula for circ joints (because of the assumption of straight seamless pipe) to UG-27, calculated using the equivalent wall thickness from B16.11. When the limits of UG-27 are exceeded, use appendix 1.
RE: B16.11 Hex Head Plug Pressure rating
RE: B16.11 Hex Head Plug Pressure rating
First, referring to B16.11 (which I found in about 2 mins on the net) there is no Class 3000 plug, they are Class 6000 only. See Note 1 to Table 1B.
Second the wall corresponding to Class 6000 is XXS, per Table 2, 0.294 inch.
Third, the minimum thickness of a threaded component is 0.31 inch, using the smaller values of Tables 5A and 6A. Since this is larger than XXS pipe, I'd just use that value, neglecting wall tolerance and threading allowance.
Fourth, using the allowable stress for a seamless product, E = 1.0, I'd calculate the MAWP of the 0.840 OD x 0.294 pipe, deducting corrosion allowance if applicable.
I mean, if I was going to do it at all.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: B16.11 Hex Head Plug Pressure rating
See note (1) in Table 6:
Plugs and bushings are not identified by class designation. They may be used for ratings up through
Class 6000 designation.
Regards
r6155
RE: B16.11 Hex Head Plug Pressure rating
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: B16.11 Hex Head Plug Pressure rating
Correct designation: NPS ½ hex head plug
Regards
r6155
RE: B16.11 Hex Head Plug Pressure rating
Do I need the fitting to conform to B16.11 in order to use it on a Section VIII vessel? Or can this part qualify as a threaded rod or bar? The plug I have now is a solid piece.
I'm trying to avoid buying a B16.11 plug if I can
RE: B16.11 Hex Head Plug Pressure rating
How much can a 1/2" B16.11 plug cost?
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: B16.11 Hex Head Plug Pressure rating
We sell a lot of instrumentation that is usually asked for B31.1 and B31.3, but recently we received our U and UM stamp certification.
Cost matters if you sell a bunch like we are. In fact, it may be cheaper for the B16.11 plug. If so, I'll look into it and make the B16.11 a standard across the board. The engineering dept here is dwindling with layoffs...
RE: B16.11 Hex Head Plug Pressure rating
That said, if you manufacture fittings that comply in all respects with B16.11, then they are B16.11 fittings and can be used as such.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand