The client were looking to carry out annual ultrasonic testing inspection of the topside pipelines of an LNG plant. The pipework was encased with insulating cladding (which needed to be removed before any inspection could take place) so they were looking for a more cost effective alternative. As a trial, they opted to install fixed monitoring sensors permanently fitted to the pipework. One option was to use clamps to hold the sensors in place but they are prone to vibration and loosening so weren’t a viable option.
Based on our existing track record with the client, Proserv were asked to perform friction welding on the pipelines, a permanent solution requiring no routine maintenance. To carry out traditional welding, this would require for the plant to be shut down; using friction welding, the plant could remain fully operational and production unaffected.
The following work was completed
- 16 Carbon Steel M8 studs on 36 inch diameter Carbon Steel pipe, 46 mm wall thickness
- 32 Duplex Stainless Steel M8 studs grade 2205 on 28 inch diameter, 25.4 mm wall thickness
- 32 Stainless Steel M8 studs Grade 254 SMO on 3 inch diameter, 3.04 mm wall thickness
Proserv successfully carried out pneumatic friction welding services for the attachment of 80 M8 studs onto live pipes for the attachment of corrosion sensors. The studs were welded on by two Proserv technicians to locations indicated by the client. The full process was witnessed by Lloyds Register.
- Permanent welded solution
- No annual maintenance required or removal of pipe lagging
- Low-cost solution
- No impact to production