Isolate the Aluminium from the Galv structure with PTFE pads to eliminate any electrical difference at the joints (where the material will corrode) then connect your earthing strap (because you could end up with static) through a sacrificial anode i,e, lead.
A lot of valves being installed in this position are trunnion ball valves.
Debris which may get trapped at the bottom of the gate can hold the gate off and stop full closure, this is not a problem with a ball valve.
The other thing is you can readily fit a Partial Stroke Device - PSD, to a ball...
I agree with terje61, if you go and specify a valve and its wrong it comes down to you, is the application your reading about 'EXACTLY' the same! Both the manufacturers and people on the plant know what works and what doesn't. Manufacturers have a wealth of experience built up over decades of...
I can see why you are confused, valve manufacturers may have a design of valve which has been Fire Tested and is therefore 'Certified' Fire safe, whether by design or not, it holds a unique certificate for its BOM.
A simple change in build i.e seat material, may then not have been tested(and...
What grade of 17.4ph are you using? I've used HH1150 for a number of years for shafts with high torque requirements within a cryogenic environment.
We soaked every one of our components prior to installation. There always appeared to be less failure issues and better performance when doing...
Whilst I've made no reference to the melting point of PVC, I know it is low. My experience from firetesting Polymer seated valves as against lined would say that (size dependant, because a large body would not get to temperature in 1/2 hour) a 6 inch valve would last less than a rubber one, say...
NGL, I totally agree with what your saying. I always get the question when showing people aroung the cryo test facility - Why are you testing with the cold media on the outside when surely it is the inside which is being used.Plus the fact that ALL tests are done with Helium gas, where the valve...