where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

694 views
Technical Discussions
Guru
Guru
00:56 Oct-14-2008
PE Coating defeats

What is the best method/system to confirm Air entrapment in PE Coating of Pipes?


 
 Reply 
 
Tom Nelligan
Engineering,
retired, USA, Joined Nov 1998, 390

Tom Nelligan

Engineering,
retired,
USA,
Joined Nov 1998
390
04:50 Oct-14-2008
Re: PE Coating defeats
If the coating is external, a simple straight beam test with an ultrasonic flaw detector and a contact transducer can usually find bubbles larger than 0.5 mm or so. Transducer selection will depend on polyethylene thickness -- try 10 MHz up to about 5 mm thickness, and 5 MHz up to about 25 mm.

If the coating is internal and there is access only from the outside, the test is significantly more difficult because of the poor acoustic impedance match between steel and polyeythlene and the numerous multiple echoes that will occur within the steel. If the PE is less than half the thickness of the steel, then any bubble echoes will occur between the first and second backwall echoes from the steel, but if the ratio is larger there will be difficulties. Testing from the ID with special fixturing is a possibility.


 
 Reply 
 
Simon Amallraja
Simon Amallraja
07:06 Oct-14-2008
Re: PE Coating defeats
----------- Start Original Message -----------
: What is the best method/system to confirm Air entrapment in PE Coating of Pipes?
------------ End Original Message ------------

You can try Holiday Detectors to identify the areas of air bubbles. This will be easy and simple, if the test reqt is not so critical like coating of PE for corrosion protection on pipes etc.,

Simon


 
 Reply 
 
faheem anjum
faheem anjum
09:22 Oct-23-2008
Re: PE Coating defeats

plz send me the coating defect book


 
 Reply 
 

Product Spotlight

VeeScan AirCraft Wheel Inspection

The VEESCAN offers maximum flexibility, has a proven mechanical design and records of breakdown-fr
...
ee operation of over 365 days. Appealing to companies in the Aerospace industry, the VEESCAN is ideal for all wheel-testing environments. With a wide selection of probes, the VeeScan allows your wheel testing facility the flexibility to select the most compatible configurations with their workload.
>

Micro CT

nanoVoxel series has nano-scale resolution upto 500nm by using high voltage X-ray source (from 80-
...
300 kV) with micro/nano focal spot and highly sensitive flat panel detectors and unique Optical coupling detector.
>

Ultrasonic Probe Recharacterization Service

NDT Systems offers a comprehensive Aftercare and Recharacterization Service for all our ultrasonic
...
probes. The Recharacterization Service is fully compliant with International ASTM E1065 Standard Guide (and other applicable standards) and offers complete documentation, traceable to the ASTM E1065 Standard. For more details or to schedule Recharacterization Services contact ndtsales@ndtsystems.com
>

Wireless TOFD scanner

Quick, accurate and highly reproducible welds testing. The System operates wirelessly and is compat
...
ible with any type of Windows based Laptop, Desktop or Tablet.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window