Phased array vs radiography prices side by side
Ranges for US NDT crews, for budgeting before you request quotes.
| Item | Phased array UT (with TOFD) | Radiography (film or digital) |
|---|---|---|
| Rate per weld, 4 to 8 inch pipe | $40 to $90 | $60 to $150 |
| Rate per weld, 12 to 24 inch pipe | $90 to $150 | $120 to $250 |
| Crew day with equipment | $1,500 to $3,200 | $1,200 to $2,800 |
| Radiation exclusion zone | None | Yes, other trades wait or work nights |
| Permanent record | Encoded scan, reviewable | Film or digital image |
| Result time | Often same shift | Same shift digital, next day film |
| Flaw height sizing | Yes | No |
| Thin wall small bore | Weak | Strong |
| Mobilization | $500 to $3,000 | $500 to $3,000 |
For how each method is priced alone, see ultrasonic testing cost and radiographic testing cost.
A worked budget for 200 girth welds
Take a fabricator with 200 butt welds on 10 inch schedule 40 carbon steel pipe, built to ASME B31.3 normal fluid service with 10 percent random examination required by the code.
- RT on 20 welds at $140 each is $2,800. If a client demands 100 percent, 200 welds at $140 is $28,000.
- PAUT with TOFD on 20 welds at $85 each is $1,700. At 100 percent, 200 welds at $85 is $17,000.
- Add RT downtime. If the area has to clear for 3 hours a shift across 10 shifts and 8 people stand idle at $60 an hour, that is roughly $14,400 in lost labor, or the cost of moving RT to nights at a premium.
- PAUT has no clearance, so the fabricator spends nothing on lost labor.
On a 10 percent job the two are close and many fabricators keep RT because the code names it. On a 100 percent job PAUT usually saves $10,000 to $25,000 once downtime is counted. These are planning illustrations, not offers. Get quotes on the same scope before you decide.
When radiography is still the better buy
Radiography wins on small bore pipe under about half an inch of wall, where the array probe lacks room. It wins on complex shapes such as castings, branch connections with tight geometry and valve bodies. It wins where the client specification says RT and has no appetite for a deviation request. It also wins when the shop has no certified PAUT crew within a day's drive, because mobilization can erase the saving. Our industrial X-ray inspection page covers the radiography side.
When phased array is the better buy
PAUT wins on thick wall welds, on 100 percent examination programs, in congested plants where an exclusion zone stops other work and in jobs where the owner wants flaw height for fitness for service. It also wins where you want to re-read a weld a year later, because the encoded scan saves every A scan. For piping campaigns this often matters more than the rate. See pipe weld testing for the buyer view of weld programs and phased array ultrasonic testing services to request a crew.
What the code allows
Check three things before you swap methods. First, whether the construction code permits UT in place of RT for your joint class. ASME B31.3 allows alternatives with owner approval, and ASME Section VIII Division 1 and 2 rules cover UT in place of RT with qualified procedures, see ASME for the current text. Second, whether your client or insurer has its own standard. Third, whether pipeline work under API 1104 has an approved alternative method. Put the answer in your purchase order, so every company quotes the same method.
What to send for comparable PAUT and RT quotes
- Weld count, diameters, wall thickness, material and joint type.
- Code, extent of examination (10 percent, 20 percent, 100 percent) and acceptance criteria.
- Whether the quote is for PAUT with TOFD, RT or both as options.
- Shift pattern, exclusion zone rules and site access.
- Deliverables: report, native scan files or film and who keeps the record.
- Who supplies scaffolding, cleaning and power.
Where this fits in your inspection budget
Weld work on process lines is part of an API 570 program, priced on our piping inspection services page. For the full NDT picture read NDT inspection cost.
Is phased array cheaper than radiography?
Often yes on a full project. PAUT with TOFD is typically $40 to $150 per weld against $60 to $250 for RT, and PAUT needs no exclusion zone, so there is less lost labor. On small jobs with a code mandated 10 percent sample the totals are close.
Can phased array ultrasonic testing replace radiography on welds?
Often yes when the code or client approves it and the crew uses a qualified procedure. PAUT with TOFD is widely accepted on thicker welds. Thin wall small bore pipe and complex shapes usually stay with radiography.
How accurate is phased array compared with radiography?
Both find volumetric flaws such as porosity and slag. PAUT is stronger on planar flaws such as lack of fusion and cracks, and it sizes flaw height, which RT cannot. RT shows flaw shape in a picture that many reviewers find easier to read.
How long does a PAUT weld inspection take compared with RT?
A trained technician scans a 10 inch girth weld in roughly 10 to 20 minutes, and results are often ready on the shift. Film RT adds exposure time, clearance and development, while digital RT is closer to PAUT.
Why do PAUT and RT quotes differ?
Quotes differ because scope differs. One may price 10 percent of the welds, another all of them, one may include scaffolding and another may not. Ask each company to list inclusions, extent and deliverables separately.
