For elbow-to-flange welding, a short circuit connector is required. How should the length of this short circuit connector be determined?

A short pipe should be added to prevent the flanges and elbows from being damaged during pipeline maintenance or modification. Furthermore, it is very necessary to add a short section of pipe for low-temperature pipes and those at higher temperatures, as welding the flanges and elbows directly causes stress concentration. There shouldn’t be any strict requirement specifying what the minimum short-circuit length should be, right?

For DN100 and below, a minimum of 100 mm; for DN150 and above, a minimum of 150 mm

This post was last edited by bfdlwolf on 2019-4-28 08:53. The length of the short pipe should be greater than the minimum distance between the two welds. The Code for Design of Industrial Metal Piping stipulates that the distance between two butt welds should not be less than 3 times the thickness of the welded part; when post-weld heat treatment is required, this distance should not be less than 6 times the thickness of the welded part. It shall also meet the following requirements: For pipes with a nominal diameter of less than 50 mm, the spacing between welds should not be less than 50 mm. For pipes with a nominal diameter of 50 mm or more, the spacing between welds should not be less than 100 mm. The Code for Construction and Acceptance of Industrial Metal Piping Projects stipulates that the distance between the center planes of two butt welds on a straight pipe section shall not be less than 150 mm when the nominal diameter is 150 mm or greater ； When the nominal diameter is less than 150 mm, it shall not be less than the outer diameter of the pipe.

Article 6.0.5 on page 16 of \"GB 50184-2011 Code for Acceptance of Construction Quality of Industrial Metal Piping Projects\", and Article 5.7.9 on page 37 of \"CJJ 28-2014 Code for Construction and Acceptance of Urban Heating Pipeline Networks\"