My question is on bracing of branches.

I have seen many consultancies and clients ask for bracings of small bore bracings to the header for header pipe pressure rating >= 600 Lbs or when the small bore branch is close to some source of vibration like connection to reciprocating or rotary equipments etc.

However when I have referred to the MTD guideline ,besides other parameters like location of small bore on header, branch length, no. of valves on the branch , header thickness etc. there is no reference to the pressure rating of the line. In fact I have made some sample calculations to find that the branch bracing is not required for a 900 lb rating line but required for a 300 lb rating line ( one simple reason is that , for the 900 lb. rating line, the header wall thickness is higher thereby having a less LOF or likelihood of failure). This is in contrast to the view in paragraph 1. Personally I have full faith on the MTD guidline and I feel that view in paragraph 1 is not having a solid scientific rigor, which the MTD guideline is having.

I would like to get the opinion of forum members on this issue.

This is not in context of high frequency acoustic vibration where bracings need not help rather can create problem due to asymmetry.

Regards