Grooved pipe-joining aids dredger retrofit
When piping systems had to be replaced on the 1983-built trailing suction hopper dredger FRPD 309 , the work needed to be done as quickly as possible.
This requirement and the desire to avoid welding for safety reasons were major factors which led the operator, Fraser River Pile and Dredge (GP) Inc of Vancouver BC, to select the Victaulic grooved mechanical pipe-joining method.
Replacement of cooling water piping on the dredger’s main engines took just one week to complete. Work on cooling water pipes for the auxiliary engines and pump engines followed.
Avoiding hotwork in an environment where fuel, oil and combustible materials were present was an obvious safety consideration. But as well as eliminating fire risk, Igor Shlyk, marine technical superintendent at Fraser River Pile and Dredge, knew that using grooved mechanical joining instead of welding would greatly speed up the retrofit work on the dredger.
Not only was the installation time reduced, but the project could also get off to a quicker start because there were none of the delays associated with welding. Shlyk explained: “As a BV Class vessel, we have to have all the procedures in place including welders’ certificates, welding procedures and hotwork permits but we could eliminate that with Victaulic products. It would have taken a lot longer to deal with all the paperwork and the people required so not having to do that was a big advantage.”
Not only was it unnecessary to degrease or cleanse the area prior to commencing work, but time consuming and costly fire watch arrangements were also avoided. And there was no need for the ultrasonic testing of welds, which would have delayed project completion. “In this case we just pressure tested the system and there were no leaks, so everybody was happy.”
The ease and convenience of the mechanical pipe-joining system helped overcome space constraints on board the dredger, where access to carry out welding would have been extremely difficult – if not impossible. After pre-measuring, cutting and grooving the pipe, pieces were pre-assembled and fitted together progressively section by section. “With welding, unfortunately you can’t do that: you have to go back and forth several times, tacking welding and removing, said Shlyk. “If we’d tried to weld, I don’t see how it could have been done.”
Similarly, any maintenance that may be needed will be much quicker and easier. A union at every joint means that a worker needs to undo just two nuts and bolts and retighten them after replacing the gasket.
As well as being simpler, the need for maintenance with a Victaulic system is much reduced, since the couplings attenuate vibration, lessening the instance of leaks and prolonging the life of the system.
