There are questions regarding valve models
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What type of valve is used for 1.6MPA gas pipelines? I know that gate valves can be used, but there are so many models of gate valves – which one should I choose? Moreover, some model numbers are difficult to understand. For example, CZ40H-16C, Z41H-16C, Z41W-16P(R): I know that the ‘Z’ denotes a gate valve, and the ‘4’ indicates gear drive with cylindrical gears. If it’s Z44, then it’s a gate valve with cylindrical gears and flange connection. But why does the schematic diagram for Z41H-16C also show a flange connection? Or does this Z41-16C refer to a gate valve with cylindrical gears and a single gate? So what is its joint configuration? And what about that C at the back? Does it indicate that the valve seat seal is made of enamel, or is the material of the valve body ZG25II? And what do those material codes represent? I can understand those with special elements, but what do HT250, KTH300-06, QT400-15, H62, and ZG25II mean? I’ve looked at JB308-75, but I still don’t understand it :( Am I just not very smart? I would appreciate some guidance from those who are more experienced.
Z41H-16C means the following: Z: indicates a gate valve; 4: the connection type is flange connection; 1: it features a wedge-shaped single gate plate; H: the material of the valve seat sealing surface is alloy steel; 16: the nominal pressure rating is 16 kg; C: the material of the valve body is carbon steel. Since this valve is operated manually, this parameter is omitted.
As an example: Z41W-16P – the letter Z denotes a gate valve; 4 indicates that the connection method is flange connection; 1 signifies that the valve has a visible stem, wedge-type, rigid single-gate structure; W indicates that the sealing material is iron – it’s just a separator symbol; 16 represents that the pressure the valve can withstand is 16 bar (the nominal pressure is 16 kilograms per square centimeter); P indicates that the valve body is made of 18-8 grade stainless steel； Z41H-16C: Z indicates that the valve type is a gate valve; 4 indicates that the connection method is flange connection; 1 indicates that the valve structure is of the type with a visible stem, wedge-shaped, rigid single gate plate; H indicates that the sealing material is Cr13 stainless steel – it is merely a separator symbol with no actual meaning. 16 represents a nominal pressure of 16 kilograms; C indicates that the valve body material is carbon steel. Connection types include internal threads, external threads, different flange connections, welding, clamping, and sleeve connections. Codes 12346789 are used for these connection types. Codes for gate valve structures include: 0 for visible-stem wedge-shaped elastic gate plate, 1 for rigid single gate plate, 2 for double gate plates, 3 for parallel single gate plate, 4 for hidden-stem wedge-shaped single gate plate, 5 for double gate plates, 6 for parallel single gate plate, 7 for double gate plates, 8 for other structures. The valve body material is indicated as follows: titanium and titanium alloys, carbon steel, Cr13 series stainless steel, chromium-molybdenum steel, malleable cast iron, aluminum alloys, 18-8 series stainless steel, ductile iron, Mo2Ti series stainless steel, plastics, copper and copper alloys, chromium-molybdenum-vanadium steel, gray cast iron. Codes ACHIKLPQRSTVZ are used for these materials. The sealing surface material of the sealing pair is indicated as follows: tin-based bearing alloys, babbitt alloys, nitrided steel, 18-8 series stainless steel, fluoroplastics, glass, Cr13 stainless steel, rubber-lined materials, Monel alloy, nylon, plastics, boronized steel, lead-lined Mo2Ti stainless steel, plastics, copper alloys, rubber, hard alloys. For valves with directly processed valve bodies, codes BCDEFGHJMNPQRSTXYW are used. When the sealing surface materials of the sealing pair differ, the code of the material with lower hardness is used.