Mechanical Bolt On Hot Tap Fittings- are they per Code?

[bosse1950]

Can anyone supply me with an actual code reference (or relevant code interpretation) to a permanently attached mechanical hot tap fitting? B31.8 Section 849.6 "Service Line Connections to Mains" makes references to: b)- using a service line clamp or saddle, and c)- using compression fittings with rubber or rubber like gaskets to connect the service line to the main connection ( I presume this is permanent fitting). Also in API 570 section 8.1.4 reference is made to clamp on fittings, but only in a "temporary" repair fashion.
These types of fittings have been around and successfully installed for well over 25 years and I am on a project where the client wants to see a code reference. Your valued input will be greatly appreciated

 

[unclesyd]

We have used the mechanical hot tap fittings on some medium pressure lines but insist on welded fitting above 250F.

I would give someone like Plidco, Red Flame, or the company supplying your fittings a call to verify code compliance.

http://www.plidco.com/public/products/hot_tapping_saddle.php

http://www.redflame.ca/html/no_weld_hot_tap.htm

 

[Ziek]

What kind of system are you looking to install the fitting onto? If it is a cross country pipeline, you can only install bolted mechanical hot tap fittings as a temporary connection and they have to be seal welded at some point in the future. This is a DOT requirement. If you are in a plant, it is likely acceptible practice, however you want a fitting with design features that will compensate for the fact that an elastomer seal will likely leak some day in the future. The mechanical fittings made by Furmanite have sealant injection ports which allow for a leak sealing compund to be injected should the seal ever degrade. They can also provide answers regarding code questions.

http://www.furmanite.com/Products/ProductDisplayPage/tabid/58/obj/196/lang/1/Default.aspx