ASME B31.1 VT requirements 2

[JoeJersey]

I originally posted this in another section before I saw this code section.

We (as Owners/operators of Combined heating and cooling plants) are trying to identify the "necessary" visual requirements for ASME B31.1 on a Chilled water, condenser water and hot water systems. We interpret the Code to require 100% Visual on all welds.(Table 136.4 in 2001 version of B31.1). I have looked through the code to find anything else and cannot find a minimum requirement. Is this entirely up to the Owner? Will the system still be considered B31.1 if we only do spot checking for visual inspections? or could we do 5% UT or RT to eliminate the need for a full time VT inspector?

 

[stanweld]

Per 136.4.2 "... visual examination shall be performed on all completed welds in pipe and piping components..."

Why are you using B31.1 for heating and cooling water systems?

 

[JoeJersey]

Stanweld,
We decided to use B31.1 for heating and cooling because our company will operate the plants for long periods of time and they wanted to choose a code that would insure proper welding so there are no problems down the road. One Plant we built had 42" pipe headers and distribution for chilled water and 30" pipe for hot water headers and distribution.

Our problem is now that we are building to an ASME code we need a full time inspector to perform the VT on and off site, this gets very costly. Is there another code you think we could use that would also provide the comfort level to our owners?

 

[stanweld]

ASME B31.3 Catagory D fluid service would appear to fit your needs.

 

[JoeJersey]

Additionally, does the VT requirement mean inspect the fit up of pipe, root weld and all fill passes after?

 

[stanweld]

If you are referring to B31.1, no.

If B31.3 Catagory D fluid service, yes "to the extent necessary to satisfy the examiner..."

 

[JoeJersey]

Stanweld - Thank you for your help so far.

Just so this is clear;

B31.1 - VT is not performed on the welding operation but on all welds in the system after they are completed

B31.3 - VT is up to the inspector, for example if the inspector witnesses the fit up through Cap weld of a handful of welds performed by a welder he may elect to say all of that welders work was performed per the code.

Is the Correct?

 

[stanweld]

Per B31.1, VT is also performed during other phases of welding but not all welds are examined. You still need to verify that welding is being performed in accordance with established procedures and that the materials are correct.

Please review 341.4.2 and 344.2 of B31.3.

 

[MJCronin]

Excellent discussion, I was also confused on this issue

Kudos Stanweld....!!!

 

[brandonb73]

In response to: Additionally, does the VT requirement mean inspect the fit up of pipe, root weld and all fill passes after?

Para 136.4.2 reads: "Visual examinations may be conducted, as necessary, during the fabrication and erection of piping components to provide verification that the design and WPS requirements are being met".

This is also were you will find the acceptance standards.