Valve raw materials such as oil circuit plate, single flow valve and piston valve are introduced in detail

Valve raw materials such as oil circuit plate, single flow valve and piston valve are introduced in detail

Oil circuit plate, single flow valve and gate valve (piston valve) is one of the key parts of the valve, immediately assume the medium working pressure, commonly used raw materials should meet the relevant provisions of “valve pressure and temperature level”. Carbon steel: Suitable for nominal pressure PN≤32.0MPa, temperature -30 ~ 425℃ water, steam, gas, hydrogen, ammonia, nitrogen and petroleum products and other media. Common grades are WC1, WCB, ZG25 and quality steel 20, 25, 30 and low alloy steel 16Mn. Stainless acid resistant steel, suitable for nominal pressure PN≤6.4Mpa, temperature ≤200℃ sodium cyanide, glacial acetic acid and other media…
Many raw materials for the production and manufacture of valve parts, including a variety of different brands of light metals and precious metals and aluminum alloy, a variety of non-metallic materials.
Raw materials for manufacturing valve parts should be selected according to the following factors:
1, working medium pressure, temperature and characteristics.
2, the bearing capacity of the parts and often play a role in the valve structure.
3. Good process performance.
4. Under the premise of meeting the above conditions, relatively low cost is required. Raw materials of oil circuit plate, single flow valve and valve plate (piston valve) Oil circuit plate, single flow valve and gate valve (piston valve) is one of the key parts of the valve, immediately assume the medium working pressure, commonly used raw materials should meet the relevant provisions of “valve pressure and temperature level”. Common materials fall into the following categories:
1, gray cast iron: gray cast iron is suitable for nominal pressure PN≤1.0MPa, temperature -10℃ ~ 200℃ water, steam, gas, liquefied gas and refined oil and other media. Gray cast iron common grade: HT200, HT250, HT300, HT350.
Two, malleable iron: suitable for nominal pressure PN≤2.5MPa, temperature -30 ~ 300℃ water, steam, gas and oil medium, common brands are: KTH300-06, KTH330-08, KTH350-10.
Three, ductile casting: suitable for PN≤4.0MPa, temperature -30 ~ 350℃ water, steam, gas and oil and other media.
Common brands are: QT400 — 15, QT450 — 10, QT500 — 7.
Because of the current technology level of our country, the factories are good and some are bad and the customers are not easy to detect. According to experience, it is suggested that PN≤2.5MPa, valve or steel valve is selected for safety.
Four, acid resistance high silicon ductile casting: suitable for nominal pressure PN≤0.25MPa, temperature less than 120℃ corrosive medium.
Five, carbon steel: suitable for nominal pressure PN≤32.0MPa, temperature -30 ~ 425℃ water, steam, gas, hydrogen, ammonia, nitrogen and petroleum products and other media. Common grades are WC1, WCB, ZG25 and quality steel 20, 25, 30 and low alloy steel 16Mn.
Vi. Alloy material: Suitable for PN≤2.5MPa water, sea, O2, gas, oil and other media, and the temperature of -40 ~ 50℃ vapor medium, common brands are ZGnSn10Zn2(tin bronze), H62, HPB59-1 (red copper), Qaz19-2, Qa19-4 (aluminum bronze).
Seven, continuous high temperature copper: suitable for nominal pressure PN≤17.0MPA, temperature ≤570℃ steam heating and petroleum products. Common brand has ZGCr5Mo, 1 cr5m0. ZG20CrMoV, ZG15Gr1Mo1V, 12 crmov WC6, WC9, etc. The actual use must be in accordance with the valve pressure and temperature standardization requirements.
Eight, low temperature steel, suitable for nominal pressure PN≤6.4Mpa, temperature ≥ -196 ℃ butadiene, pe, liquid natural gas, liquid nitrogen and other media, common brands) are ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9
Nine, stainless acid resistant steel, suitable for nominal pressure PN≤6.4Mpa, temperature ≤200℃ sodium cyanide, acetic acid and other media, common brands are ZG0Cr18Ni9Ti, ZG0Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, acid resistance and urea solution
The final diameter error of disc and trapezoidal free forgings cannot be controlled because of the width and edge deformation of copper and alloy steel castings of valve raw materials, so no dimensional tolerance is required. Proposed supplier and order to place before purchasing materials, or the amount of such product embedded machining surplus. Burrs caused by rough edges, punching parts, punching machine, or passing over the die guide post of the forging die are permitted as long as they are removed during machining or are not harmful to remain in the finished product (G1,G2,G3, and G4 in FIG. 9). The drawing should indicate that such raw edges should not exceed 1.5 mm
Connecting: Steel castings of copper and alloy materials for valve raw materials (II)
Dimensional errors in and across die – parting lines
Raw material group I, specifications, and t should conform to the deviation range given in Table 14, while raw material group Ⅱ should conform to Table 15, raw material group Ⅲ
The larger specification of calcination Angle, tmax, is the basic dimension of the available dimensional tolerance across the specification t of the parting line. The error of tmax lies in the development area A of the hard strike Angle of the part. In the case of annular parts, the total area A is equivalent to the area of A circle; in the case of irregular parts, the total area A is equivalent to the area of the outer cut rectangle (see Figure 4). All smaller specifications t have the same error as tmax.