The procedure of Post Weld Heat Treatment projects is often recorded in a quality document beforehand. It lists the requirements that should be met for the relevant heat treatments and that will lead to a guaranteed result.
Post Weld Heat Treatment (PWHT) is the international term for stress relief annealing: a heat treatment that is carried out – among other things – after welding work to minimise thermal stresses within the steel.
Certain projects require a PWHT procedure. This often involves projects related to (petro)chemicals, boiler and equipment engineering, and offshore, where constructions or storage tanks must comply with specific requirements of a quality mark or certification, for example. The insurer of such projects often requires a procedure too. Smit Heat Treatment records this procedure in the so-called Heat Treatment certificate: a quality certificate that guarantees the required result.
The PWHT procedure lists a step-by-step description of the regulations the heat treatment must comply with. Aspects such as temperature, heating rate, holding time, positioning of the product in the oven and placement of monitoring points are listed in the quality document. These specifications vary for each project and depend on the material, the dimensions of the work and the application of the product, to name but a few. Prior to the heat treatment, both parties involved – you as our client and us as the executor of the treatment – must provide agreement on the procedure.
It is possible for the procedure to be drawn up by you, the client. Larger companies often have their own in-house metallurgist for this purpose. In case you cannot avail yourself of the necessary knowledge for drawing up a procedure, Smit Heat Treatment would be pleased to be your sparring partner. We have extensive in-house knowledge related to all material-technical aspects and adopt a practical approach to every heat treatment. If required, we can create the complete procedure on your behalf. Our many years of experience allows us to guarantee the desired result. We utilise creative solutions and do not shy away from challenges. Even complex projects are right up our alley.