NEW LOW TYPE NOZZLE WITH HOT TAP PROCEDURE

[ROMEUM2]

Dear all,

I have a question regarding hot tap procedure in an existing tank. We have to include a new nozzle in an existing tank using hot tap system (according to API 653 and 2201), and i would like to know if i can use a regular or low type nozzle. It's important because the elevation of the new nozzle meets the low type nozzle requeriments but not for a regular type.

Thanks in advance,

 

[LittleInch]

Try posting a similar question in the storage tank forum linking to this one. I don't know the answer but the mech eng / storage tank engineering guys might

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[IFRs]

API 653 Figure 9.14 clearly shows a circular repad with weld spacing to the corner weld require to be in accordance with API 650 5.7.3. Size the repad to achieve adequate reinforcement in accordance with 9.14.1.1.3. Do the calcs, check against each and every section of 9.14 and see where your nozzle elevation is. I would not worry too much about "regular" and "low" type elevations since the hot-tap portion of the code does not refer to those terms. If you can't make it work, don't do it.

Note the last sentence:

API publications are published to facilitate the broad availability of proven, sound engineering and operating
practices. These publications are not intended to obviate the need for applying sound engineering judgment
regarding when and where these publications should be utilized. The formulation and publication of API publications
is not intended in any way to inhibit anyone from using any other practices.