The Valve manufacturing process starts life as a plain rod of 1.4882 Austenitic Stainless Steel or EN52 Steel which is then electrically upset to form a bunt, which is then forged into a close limit forging

After being forged the valve goes through a number of machining and grinding operations before final inspection in our quality department.

After final inspection the valve goes through a pulsed plasma treatment .

After Plasma treatment surface hardness is then checked in the metallurgy lab.

Pulsed Plasma Nitride
Valves for internal combustion engines must have high resistance to thermal stress caused by frequent temperature changes. They must remain ductile but acquire good anti-friction properties to reduce wear in the area of the valve guide. The valve seat must be able to resist the corrosive effects of hot exhaust gases from the engine.

Pulsed Plasma Nitriding improves the resistance to wear and the anti-friction qualities by increasing the surface hardness along the valve stem, while retaining the inherent corrosion resistance of the material at the valve seat. Pulsed Plasma Nitriding allows high temperature metallurgical reactions to occur at low work surface temperatures, plasma is produced by applying high voltage through a low pressure gas (a mixture of hydrogen and nitrogen) causing it to ionise, using this high energy (but thermally low temperature), plasma will diffuse nitrogen into the surface of the valve.

Some of the advantages of Pulsed Plasma Nitriding are:

 1. This process is applied at low temperature so it does not affect the original core properties of the substrate material.

2. The nitride layer is more uniform and there is less deviation from mean values, when compared to salt bath or gas nitriding.

3. The anti-friction qualities between the valve stem and the valve guide have been substantially improved.

4. Plasma Nitrided surfaces offer better protection against adhesive and abrasive wear

5. Due to the low temperature process the dimensional stability of the valve is improved.

6. Valves can be masked to allow specific parts to be treated

7. Using this process it is possible to allow other treatments to be applied to further enhance the properties of the valve