Hot Tapping

Yes , very answer Regards Alejandro quiroga www.interviv.com

As with all questions, more information is required prior to providing an accurate and robust solution.

First off, what material is the pipe that you want to hot tap? (Carbon Steel, Ductile Iron, PVC, PE, etc) If Carbon Steel what is the grade and yield strength?

Secondly, what is the minimum flow rate required through the tapped hole to suffice the downstream feed? This will help us accurately size the OD of the tapped hole.

Lastly, what is the:

- pressure in the pipe

- what is the fluid in the pipe

- OD of the pipe

- wall thickness of the pipe

- design code (B31.3, B31.4, B31.8)

- main purpose of the hot tap

Once those questions are answered, we can move further down the path of finding a solution to your specific request.

Now to answer your question, and provide a few key points to ponder…

Yes, it is possible and acceptable, in many cases, to make a 3" Hot Tap on 3" Nominal Pipes. The re-enforcement requirements will vary depending on the Design Pressure of the pipe, the Pipe Material, the Pipe Wall Thickness, the Branch Material, and the Branch Wall Thickness.

There are many cases a simple pipe nipple (http://www.tdwilliamson.com/en/Products/Fittings/HighPressure/Pages/THREAD-O-RINGFittings.aspx) will suffice. Other situations may require a "Full Encirclement" type fitting (http://www.tdwilliamson.com/en/Products/Fittings/HighPressure/Pages/TDWTappingFittings.aspx) to add extra re-enforcement.

If you have access to one of the code books (B31.3, B31.4, or B31.8) they have the step by step calculations for how to size a standard branch connections and it shows how to size the necessary re-enforcement, for the specific code only, each code has slight variations. Or, you can contact your local T.D. Williamson Rep (http://www.tdwilliamson.com/en/ContactUs/Pages/Home.aspx) and they will guide you down the path of least resistance!

Good luck on your search, and make sure you contact a professional service to perform such a task due to the critical nature and the health exposure of working in close proximity to pressurized pipelines!

Very answer Regards Alejandro quiroga www.interviv.com.

Thanks very much for everyones useful input. We have the answer to our query. The main issue was if 3" hot tap could be made on a 3" run pipe. We have done several hot taps of smaller dia on larger dia pipes in our LPG facilites but this is the first time for the above.

Make sure the OD of the Hole Saw you use is smaller than the ID of the 3" pipe. if not you will never be able to retrieve the coupon.

Yes, It is very much possible to do size on size hot tap. Use of split tee (Full Encirclement) is the best option as hot tap fitting.

Regards,

Nikhil