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Thread Inserts on Pressure Boundary

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JamesBarlow

Mechanical
Joined
Feb 4, 2002
Messages
186
Location
US
Had a miss-communication between myself and a vendor supplying a part. Vessel was taped with 1/2-13 holes and the vendor part required 3/8-16.

Neither the vessel or supplied part can be modified easily.

I can either buy or make thread inserts that will go into the 1/2-13 hole and leave me a 3/8-16.

Vessel is Sect 8 Div 1 low pressure so there is no problem with strength. I've done some searching already but have not found anything yet.

Is there anything in the code that prohibits the use of inserts as long as the calculations from UG-43 say it's fine?
 
ASME Boundary ends at the first sealing surface in a threaded connection.... REF: ASME Section VIII Div 1 Paragraph U-1(e)(1)

U-1(e)(1) where external piping; other pressure vessels
including heat exchangers; or mechanical devices, such
as pumps, mixers, or compressors, are to be connected to
the vessel:
(a) the welding end connection for the first circumferential
joint for welded connections [see UW-13(h)];
(b) the first threaded joint for screwed connections;
(c) the face of the first flange for bolted, flanged
connections;
(d) the first sealing surface for proprietary connections
or fittings;

NOTE: This does not cover threaded plugs, only connections...with that said.... helical-coil threaded inserts configurations have been considered according to U-2(g) of Section VIII-1. and the NBIC does not address this either.... in the end, get the opinion of your AI.... that is why he is there.


FAQ731-376 A question properly stated is a question half solved.
 
Go with !/2" piping connection and reduce to 3/8" connection.
 
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