In the production process of pump valve parts, the process flow needs to be strictly controlled to ensure the quality of manufacture and assembly, and to ensure the performance requirements of the whole machine. In the process of heat treatment, it is also necessary to comply with the corresponding inspection specifications to meet the production standard requirements of pump and valve fittings.
In fact, in the production process of pump valve fittings, except for the valve parts, valve cover castings or forgings, the parts required for the drawings include heat treatment of pressure control parts, opening and closing parts, pins, keys, shear rings and other parts. Moreover, the valve body, bonnet castings or forgings are subject to the heat treatment of the supplier according to the corresponding material standards, see the incoming inspection. The hardness is usually checked by sampling.
For some pump valve accessories that need to be quenched and tempered, such as valve stems, pins, keys, shear rings, drive rods, etc., the sampling ratio is 10% of the hardness of each furnace. Recorded by Brinell hardness HB. The surface nitriding heat treatment such as rods, plugs, etc., sampling ratio is recorded according to the Vickers hardness HV mark of 10% of the surface of each furnace.http://www.dmgcastings.com/