Standards And Advantages And Disadvantages Of Cast Steel Gate Valve
Mar 13, 2021
In fact, cast steel gate valves are mainly divided into two types of sealing surfaces, one is automatic sealing, which uses the pressure of the medium, and then automatically seals when it is formed. Then, the forced seal depends on the external force. Although they rely on different media, the sealing effect of the two is similar. The cast steel gate valve is used as a shut-off device in pipelines such as tap water, petroleum, and chemical industries.
Standards and advantages and disadvantages of cast steel valves
1. Standard specification:
Design and manufacturing standard: GB/T12234-2007
Structure length standard: GB/T12221-2005
Connecting flange standard: GB/T9113
Pressure temperature rating: GB/T12224-2005
Test inspection standard: GB/T13927-2008
2. Advantages and disadvantages
Advantages: Now let's take a look at the specific advantages of cast steel valves. First of all, it not only has low resistance in terms of fluid resistance, but also its sealing surface is not brushed and corroded by the medium. It is labor-saving to open and close, the medium flow direction is not restricted, does not disturb the flow, does not reduce the pressure, the structure is simple, the structure length is short, the manufacturing process is good, the high temperature and high pressure resistant materials are available for a wide range of applications.
Disadvantages: There are also some defects in cast steel valves. Let's briefly understand that between the sealing surfaces of cast steel valves, it is generally easier to cause erosion and scratches, so it will be more repaired. difficult. The size of the cast steel valve will be larger in appearance, it needs yiding space when opening, and its opening and closing time will be longer.
Classification of cast steel valves
Nowadays, there are many types of cast steel valves on the market in terms of materials. First of all, let's first understand the four different cast steel valves, and the various specific steel grades of each cast steel gate valve. Carbon steel gate valve casting grades are: WCA, WCB, WCC, LCB, etc., applicable temperature -46 degrees -425 degrees, stainless steel gate valve casting grades: 301 stainless steel, CF8 stainless steel. CF8M stainless steel (corresponding to forging 316 stainless steel), etc.; applicable temperature -198 degrees -816 degrees, low alloy steel is divided into high temperature alloy steel and high strength low alloy steel, of which high temperature alloy steel is often referred to as chromium molybdenum steel. Casting grades of chromium-molybdenum steel gate valves: ZG1Cr5Mo, ZG15Cr1MoV, ZG20CrMoV, WC6, WC9, C12A, etc. The applicable temperature ranges from 550°C to 750°C. The applicable temperature for each specific grade material is different, depending on the actual working conditions.
2. Carbon steel valves can be divided into two types of steel valves, that is, cast steel valves and forged steel valves, which are manufactured by casting and forging respectively. Forging is plastic forming. Casting is formed by introducing liquid metal into the mold at one time. Relatively speaking, forging is better than casting, because the forging process does not produce pores and impurities, but the cost is relatively high.
