[Richard Beale]

[quote]FYI …I see a fair amount of “cold” connections being use these days, usually on low temp critical commodities …fuel gas, vapor recovery headers, vacuum lines, exotic alloy pipe, etc. These are “saddles” that are held in place with U-bolts, the branch connection on these saddles have a large/thick O-ring type gasket to seal this attachment, these tend to be on the smaller size (biggest I’ve seen is 4″).

I’ve never seen or heard of this, and I’m having a hard time visualizing it. Half saddle or full saddle? Are the O-rings on the saddle or the branch? If on the saddle, are there two halves to the saddle and how would the seam be sealed? If on the branch, how do you seal the saddle on the header (surely U-bolts alone won’t suffice), and what type of connection forms the branch? There must be cutting involved into the header, much like the removal of a hot tap coupon?

Getting more back on topic, it is very gracious of you to share your friends comments. Not to be contrary, because I too agree that the world is full of differring interpretations of terminology, but I have to agree with your friend. Hot tapping by my definition is welding onto and cutting into a live line while it remains in service. Cold tapping is joining into a line taken out of service, either by spool replacement between two flanges, with the added branch as you describe, or cutting a tee or O’let into the line by welding. The former requiring of a cold work permit (no welding) and the latter requiring of a hot work permit (welding required).