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monolithic insulating joints or insulating kits?

monolithic insulating joints or insulating kits?

monolithic insulating joints or insulating kits?

(OP)
I am involved in a natural gas 36”OD, API 5L (grade not yet defined) pipeline project in Venezuela.
Regarding Cathodic protection for valve stations, a colleague told me that use of monolithic insulating joints is obsolete; therefore insulating kits (gasket, sleeves and washers) must be used.
My main experience is on process plants, not on cross country pipelines, and I have no previous knowledge of monolithic insulating joints. So, I decided searching through Google in internet, and I found very good and updated information on MIJ.
My question is:
Besides lower initial cost, what other advantages have insulating kits to be preferred for this application?

RE: monolithic insulating joints or insulating kits?

I've only installed one, but one advange for us was that we could bury it without trying to coat a flange.  It also can't shift and start to leak like a flange possibly could.  

I've been pleased with the one I was involved with, but that's not really much of a test.  

RE: monolithic insulating joints or insulating kits?

The insulating kits are designed for small currents insulation. The MIJ's are designed for insulation against large and small currents, able to take lightning strikes (unlike the insulating kits). I don't know what was the basis for your coleague to dismiss the MIJ's, but I believe that's incorrect and the insulating kits are not acceptable alternative for the cross country underground gas piping insulated with MIJ's. Except perhaps for 20 m long run of 1" fuel gas line buried in the regulator yard, where the insulating kit is an extravagant expenditure.
cheers,
gr2vessels

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