Welding takes place on particulars that need to increase the corrosion resistance, or hardening of the sealing area according to the customers’ technical specifications.
The main materials used to make welding claddings are stainless steel F316 / F316L, Inconel 625, Stellite grade 6, grade 12 and other materials.
Taking into account the different behavior of the materials, it is often necessary to perform a thermal treatment before and one after welding overlay.
Depending on the characteristics of the valves, welds are performed in critical areas.
Here are some examples of details on which specific welds are made:
- The metal profile sealing profile.
- The area of the back sealing seat of the closure.
- Some parts of the Top-Entry Valve Spring Holder Rings.
- Balls that can be cladded in the passage hole or entirely.
It is possible to perform some non-destructive tests (NDE) such as LP (Penetrant test), UT (Ultrasonic test), RT (Radiographic Test), PMI (Material Test Identification), MP (Magnetic Test).
The coatings are in accordance with ASME regulations with WPS-PQR qualifications and WPQ-WOPQ qualified staff.