Post weld heat treatment (PWHT) is another important line of work for INTEC-HEAT. In this case, in addition to performing the heat treatment process, INTEC-HEAT performs the study and specific procedure.
The main objective of PWHT is to relieve the residual tension generated during the welding process. This treatment:
– Reduces the chance of cracking by evening out tensions in the weld.
– Improves ductility and reduces hardness.
– Improves resistance to corrosion and cracking due to caustic action.
– Increases the stability of the weld in later mechanical works.
These treatments can be carried out using different techniques:
– Conductive (electrical resistance)
– Convective (burners or electrical resistance)
The conductive method with electrical resistance uses ceramic fibre, band, snake, and other resistors suited to the dimensions of the equipment, together with control, programming, and automatic recording equipment. This is the most common method in the case of repairs and/or local applications in the field, mainly on pipes.
Currents induced by high frequency coils generate the necessary heat to bring the metal to the temperature required for treatment.
Calculate the number of coils and length of cable needed to achieve the objective.
In internal combustion treatment, heat is generated with burners (gas/diesel) and transferred to the weld by convection. This method is used for large pieces of equipment which require very high power levels, and with geometry that allows for the treatment to be carried out with the equipment acting as a furnace. This means isolating the equipment to improve energy efficiency.
INTECT-HEAT has specific diesel or gas equipment adapted to the needs of our clients. The main pieces of equipment treated are spheres and large deposits.
INTEC-HEAT has specific diesel or gas equipment adapted to the requirements of our customers. Mainly the treated equipment are spheres and large deposits.
Intec-Heat has fixed and portable furnaces, which, thanks to their modular configuration, allow us to adapt to everything from the smallest part to very large parts with complex shapes.
The burners used for heat treatment can either use gas or diesel as fuel according to the size of the equipment and the availability of the fuel. This type of treatment is also advised for pipe prefabrication works where the processing volume is very high.