RangerBill
Petroleum
We have an application on a current project where we are using 1/2" bore double block and bleed valves at high points in a subsea manifold piping system (2-1/16" API 6A 10K flange faced, Duplex material). The compact valves are machined out of a single block of Duplex material with 10K flange faces and tapped for studs. The valves are mounted onto 'Weldoflange' type reinforced branch connections with SBX gaskets.
There is a project 'suggestion' to use bolts through the mating branch flange into the tapped holes in the valve blocks instead of pre-fitted studs and then nuts.
I am concerned about this for several reasons: The threads in the expensive valve block become sacrificial rather than the stud/nut interface being the 'consumable'. The bolts need to be very accurately sized in length to ensure that a minimum strength engagement occurs and that bottoming out in the full thread section is avoided.
Are there any known gauling problems with L7M bolts into Duplex?
Real piping engineers thin on the ground here..... i.e. nil
Any thoughts much appreciated.
There is a project 'suggestion' to use bolts through the mating branch flange into the tapped holes in the valve blocks instead of pre-fitted studs and then nuts.
I am concerned about this for several reasons: The threads in the expensive valve block become sacrificial rather than the stud/nut interface being the 'consumable'. The bolts need to be very accurately sized in length to ensure that a minimum strength engagement occurs and that bottoming out in the full thread section is avoided.
Are there any known gauling problems with L7M bolts into Duplex?
Real piping engineers thin on the ground here..... i.e. nil
Any thoughts much appreciated.
