Minimum distance between two butt weld joints or supporting welds

Dear experts,

Can anyone pleasure advise the minimum distance between two butt weld joints or supporting weld for piping process?

Where can I refer to ?



Minimum distance of between CS weld are mostly mentioned in specifications,
If not, here photo for your references.

In case of small diameter, this requirement is not applied for fittings such elbow, tee, reducer of BW 1" and included 1".

So, you may make a TQ to clarify.

(photo from internet)


Depends on Client specifications are:

  • Required to extent pipe, with minimum length, or
  • Required to buttering BW end.

Here is photo extent length of Tee’s hub by buttering BW 25 mm for Tee NPS 4" XXS A105N, then machining to archive wall thickness (XXS).



1 Like

My understanding : min. 50 mm or 4 x wall thickness. Whichever is greater.

Do you perform NDT after buttering ???

We did 100% MT and RT.
RT film interpretation are inluded weldment and plus 25 mm in buttering site.

(It is required by Client)


Any recommendations distance from BW joint to shoe support weld joint?

Follow the approval drawings or client requirement

1 Like

Too many questions related min. distance between 2 BW joints.
In case of 2 welded joints on small size of Elbow or Tee NPS < 3/4", the distance may less than 50 mm.

So, you need summary the issues or given recommendation, and then make a Technical Query to your client to get approval before welding. Also the same question of min. distance from supporting weld to BW or other welds.

1 Like