Pipe weld inspection

[landrover77]

Wondered if i could recieve some advice,

I'm attempting to re-start coding welding within the company i work for, based i the UK.

We have lost the knoweldge regarding weld inspection.

Our welders have completed the required coding for the welds they are performing.

However we are producing PED vessel and piping for operation within the UK, and so thus designing to PED requirements.

The vessels we have inspected externally, but in the case of the pipework, my understnding is that i need an inspection of 10%.

I would like to bring this in-house eventually, and was going to begin by sending someone on the required training courses.

However i'm not entrely sure of the most appropiate methods.

VT is not an issue we have experience of this, as are dye testing.

However am i required by current standard to go beyond surface checks? Ie into ultrasonics or x ray on piping?

Pipe is 1"-8" SCh 40. Butt welds and socket weld connections.

Also will ultrasnoics give good results with low diameters.

Many thanks?

 

[rustbuster]

Phased Array UT is widely accepted for butt welds and does not interupt the work force as radiography does.

 

[deco0404]

Creed,

the pipe size and diameter are too small for conventional ultrasonic inspections. I am not too familiar with phased array and TOFD, but do know that the probes are bigger, and as such will cause problems as well.

It is a while since I have done PED work, but I thought the NDT needed to be done by a third-party.

You might also want to consider the economics of setting up in-house NDT. You would need a lot of work to make it a viable option

Declan

 

[Duwe6]

Concur on using a Third Party NDE provider. Phased Array with a curved transducer 'shoe' will work down to at least 25mm / 1-inch OD.

You will also need a Visual inspector to sign off your VT of a percentage of fitups, in-process, and final welds. In some Coded, 100% VT of Final welds is required. Use 3rd-Party for now, send a couple of [willing] junior engineers or senior welders to an Am. Welding Soc. Certified Welding Inspector - CWI - prep class and then to Certification testing. Using 3rd-Party for VT gets expensive, fast. In-House is also better, because it will bring in welding expertise and should upgrade your shop's welding performance.

 

[REGRUMBLE]

My understanding of VT inspection will still require a Level III inspector to supervise and sign off your junior people. Just sending a couple junior people to the CWI course does not qualify you to do VT.

 

[ndeguy]

We are currently examining 4" dia 8,5mm w.t. TIG welds with PAUT, concurrently with RT (on different welds). So far we have 2 repairs (both LOSWF), RT no repairs on approximately the same number of welds. Our PAUT work is on-going without disturbing welding or other work nearby. RT is carried out in the lunch break and even roadways are blocked!. PAUT tests approx 50 welds per shift, RT 7 or 8 during the 1 hour lunch break. PAUT issues repairs immediately and the repair can be complete and finally accept tested within 1 hour, on our site each RT repair can take up to 36 hours to complete as the films are processed and viewed off-site.

We are using appropriate precision machined radiused wedges with 5L64 (5MHz, 64 element) transducers (necessary for multi-group work). There are smaller wedges but can only be used for 1 16 element group at a time. We have such wedges down to 2" diameter. We also have a low-profile "bracelet"-type scanner for work down to 1 1/2" diameter and 5mm w.t. with restricted access, e.g. water walls.

creed12, you will need to find a reputable PAUT service company with skilled personnel to carry out such work.

Regards

Nigel

 

[OlympusSA]

Creed,
Olympus has brought to the market a small pipe weld inspection solution using PA technology. The dedicated scanner and probes have been optimized to do the inspection of pipes from 0.84" to 4.5". I attached the brochure of the Cobra scanner. You can also find this information on our web site.

http://www.olympus-ims.com/en/scanners/

Regards,
Simon