Valves generally refer to control components that are relatively small in size, and are mainly composed of a valve body and various operating mechanisms, which also contain a large number of parts and accessories. Valve accessories include a wide range of products, including valve bodies, valve plugs, valve stems, valve covers, valve mufflers, handles, handwheels, worm gears, blanks, bolts and nuts, clamps, springs, diaphragms, packings and discs. Root and so on.
In addition, some o-rings, gaskets, etc. used by us also belong to the valve fittings, in which the stem is a typical accessory product. Next, we will mainly introduce the production and processing methods and maintenance requirements for the valve stem. This fitting will come in contact with the medium during valve use and there will be relative frictional motion between the packing and the packing. Therefore, the valve stem needs to maintain a certain degree of corrosion resistance and wear resistance.
In order to meet this requirement, when manufacturing and processing stems for valve fittings, it is necessary not only to select suitable materials, but also to perform corresponding heat treatment, while also performing certain surface treatments. For the valve stem, there are many surface treatment methods that can be used, such as chrome plating, electroless nickel plating, nitriding, and the like. Nitriding is a common surface treatment method. Compared with the plating layer, the nitriding treatment process has the advantages of low cost, low industrial pollution, and difficulty in delamination during use, so the process is currently used more.
When using the valve, in order to ensure normal use, it is necessary to strengthen the overhaul of each valve component. For example, when the valve is dismantled, use the steel word on the valve and the flange connected to the valve, make a maintenance number, and record the working medium, working pressure and working temperature of the valve so that the corresponding materials can be selected for repair.
Note that when servicing valve accessories, it should be done in a clean environment. First, the surface should be cleaned, the appearance of damage should be checked and recorded. In addition, the valve cover of the valve fittings needs to be tested for strength, and non-destructive testing is also required under special circumstances.http://www.pump-casting.com/