Kylm kochunny,
46" pipe with long. seam staggered 35degrees, the length between 2 longitudinal seams is about 360mm.
The AWS D1.1 code book specified "shall be" 90degrees means a mandatory requirement if client approval is not obtained .
(of course more accurately the code book should specified also a minimum staggered length that 2 longitudinal welds will no longer affect each other)
but with staggered length of 360mm, i think you got a chance to get the approval from your client.
* For offshore pipeline construction according to DNV standard, the staggered length is required minimum 50mm only.
Since this is for different application, so i do not think you can use it as a reference.
Regards,
Noel Tan