WPCT: Easiest Field Joint Coating Out There?
In the world of field joint coatings, engineers have a variety of options to consider when selecting their preferred corrosion prevention technology. For the sake of this specific article; I'll not be touching on technical aspects (cathodic disbondment, tensile strength, peel, shear, penetration resistance, etc). Instead I'll be focused simply on installation method and special tools needed.
Now the range of special tools need for applying a field joint coating is quote large. To put fusion bonded epoxy onto a field joint will require an induction heating coil and equipment to act as a vehicle to get the powdered epoxy onto the steel of the pipe. Two part epoxies (Powercrete J, Powercrete R65/F1 and Powercrete R95 are examples) require an anchor pattern in the bare steel and adjacent factory applied coating that is created with a grit/sand blaster.
Today we are looking at WPCT manufactured by Covalence (formerly Raychem). WPCT has decades of successful use history with hundreds of thousands installed per year. WPCT can be installed on a wire brushed surface that is free from all dirt, grease, dust or any other contaminant. From there, all you need for the WPCT installation is a propane torch that is able to provide a broad, bushy flame. That is essentially all.
Inspection is easy as well. The WPCT sleeve backing is supplied with a backing that looks like this:
|A close up of the dimpled backing of the WPCT shrink sleeve as supplied|
|WPCT shrink sleeve backing after proper installation.|