Re: x-ray of 42" welded joint

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Re: x-ray of 42" welded joint
Posted by: Ed Ginzel (PID_67), E-mail: eginzel@mri.on.ca, on December 28, 2002 at 15:47 :
In Reply to: Re: x-ray of 42" welded joint posted by : Ed T. , E-mail: trotteje@yahoo.com, on December 28, 2002 at 04:29 :
Contrary to Mr. Trotter's assertions, X-ray of pipelines, even double-wall tie-in shots, is the normal option for large diameter pipeline weld inspections. Use of X-ray with Class 1 film has been a requirement in Canada for 20 years. Crawlers are ideal for the production of the mainline radiographs but when the sections are tied together the crawler cannot be used as it cannot be inserted into the pipe. Instead, multiple exposures are required (4-5 around the girth) for those few welds considered "tie-ins".. Yes, this can be awkward as the X-ray tube is usually heavy, but it is necessary. Harnesses are available that allow the tube to be secured and even moved around the girth for each exposure. Securing the tube to the pipe is a 2 man operation. The tie-in X-ray crew would normally have their own truck complete with darkroom and the gas-powered electric generator for both the X-ray tube and the processing facility operations.
Use of Ir-192 for detection of lack of sidewall fusion in a double wall exposure will provide a low probability of detection, it is for this reason we preferred X-ray in all situtations where radiography was used.
Ed
: : Dear friends,
: : How can you do tie in joints using crawlers. Looking at requirement of X-ray only. I would like to know that if any body has experience and could guide me on my query such as KV, Practical time required and relevant details.
: .
: You didn't mention tie-ins in your original posting. I still am wondering why you would want to use x-ray on pipelines? I would also question why your client would require it.
: : Thanking you in advance,
: .
: : Paresh
: .
: :
: :
: : : : Dear members,
: : : : Could you please clarify following:
: : : : 1. How much kV machine is suitable for taking double wall X-ray (directional) for 42" 23mm thk welded joint of pipe.
: : : : 2. Has anybody carried X-ray for this size of joint?
: : : : 3. What is practical time required for one joint?
: : : : 4. Anybody has used X-ray for pipelines.
: : : .
: : : : Awaits early reply.
: : : .
: : : : Paresh
: : : .
: : : .
: : : My question is why would you want to use x-ray on a pipeline unless you are using a crawler. A Ir192 source is portable and can keep up with the spread if you have a portable darkroom at the site. X-ray machines require a power source and are too bulky for double wall shots. That's at least 3 shots per joint depending on your density variations with that thickness. Why don't you just get a crawler if you want to use x-ray and shoot panoramic shots?
: : .
: .
.

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Re: x-ray of 42" welded joint Ed Trotter 13:04 12/29/2002 (0)

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: Contrary to Mr. Trotter's assertions, X-ray of pipelines, even double-wall tie-in shots, is the normal option for large diameter pipeline weld inspections. Use of X-ray with Class 1 film has been a requirement in Canada for 20 years. Crawlers are ideal for the production of the mainline radiographs but when the sections are tied together the crawler cannot be used as it cannot be inserted into the pipe. Instead, multiple exposures are required (4-5 around the girth) for those few welds considered "tie-ins".. Yes, this can be awkward as the X-ray tube is usually heavy, but it is necessary. Harnesses are available that allow the tube to be secured and even moved around the girth for each exposure. Securing the tube to the pipe is a 2 man operation. The tie-in X-ray crew would normally have their own truck complete with darkroom and the gas-powered electric generator for both the X-ray tube and the processing facility operations. : Use of Ir-192 for detection of lack of sidewall fusion in a double wall exposure will provide a low probability of detection, it is for this reason we preferred X-ray in all situtations where radiography was used. : Ed : : : Dear friends, : : : How can you do tie in joints using crawlers. Looking at requirement of X-ray only. I would like to know that if any body has experience and could guide me on my query such as KV, Practical time required and relevant details. : : . : : You didn't mention tie-ins in your original posting. I still am wondering why you would want to use x-ray on pipelines? I would also question why your client would require it. : : : Thanking you in advance, : : . : : : Paresh : : . : : : : : : : : : : : Dear members, : : : : : Could you please clarify following: : : : : : 1. How much kV machine is suitable for taking double wall X-ray (directional) for 42" 23mm thk welded joint of pipe. : : : : : 2. Has anybody carried X-ray for this size of joint? : : : : : 3. What is practical time required for one joint? : : : : : 4. Anybody has used X-ray for pipelines. : : : : . : : : : : Awaits early reply. : : : : . : : : : : Paresh : : : : . : : : : . : : : : My question is why would you want to use x-ray on a pipeline unless you are using a crawler. A Ir192 source is portable and can keep up with the spread if you have a portable darkroom at the site. X-ray machines require a power source and are too bulky for double wall shots. That's at least 3 shots per joint depending on your density variations with that thickness. Why don't you just get a crawler if you want to use x-ray and shoot panoramic shots? : : : . : : . : . .

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