2013年9月25日星期三

About of the electric three way control valve

Because of ptfe with strong corrosion resistance, stable performance, not easy to aging, low coefficient of friction, easy to shape, size stability, and can be through the fill in, add the appropriate materials to improve its comprehensive performance, get better strength, lower coefficient of friction of butterfly valve sealing material, overcome the limitations of the synthetic rubber, thus represented by PTFE modified polymer materials and their filling materials, has been widely used in butterfly valves, so that the china butterfly valve performance was further improved, making the temperature and pressure range, reliable sealing performance, longer service life of the butterfly valve.
In order to meet the high and low temperature, strong erosion, electric three way control valve industrial applications such as the use of the requirements, the metal sealing butterfly valve has been great development. With high temperature resistant, good low temperature resistance, strong corrosion resistance, strong abrasion resistance, high strength alloy material in the application of butterfly valve, metal sealing butterfly valve in high and low temperature, strong erosion, long life and other industrial fields has been widely used, appeared a large diameter, high pressure and wide temperature range of butterfly valves, so that the butterfly valve technology has reached a whole new level.
Valve in the fully open, has small flow resistance. When open in about 15 , and sensitive to flow control, thus in the area of the regulation of large diameter butterfly valve application is widespread. Because of the butterfly valve butterfly plate movement with a wipe, so most of the butterfly valve can be used in the medium with suspended solids. Based on the strength of the seal, also can be used for powder and granular media. Butterfly valve is suitable for flow control.
Because of the butterfly valve in the pipe pressure loss is bigger, about three times the gate valve, so when choosing butterfly valve, pipeline system is affected by pressure loss should be considered, but should also consider closing the butterfly plate the strength of the pipeline medium under pressure. In addition, still must consider resilient seat materials at high temperatures on the operating temperature limit.
Smaller length and the height of the overall structure of butterfly valve, opening and closing speed faster, and has good flow control characteristics,china valve supplier. The structure and principles of butterfly valve is best suited for production of large diameter valves. When the butterfly valve as a control flow using one of the most important is the right choice of butterfly valve specifications and types, and making it work properly and effectively.

2013年9月24日星期二

The advantages of gate valves

As a kind of gate valves, all processed with forging material of gate valves are collectively referred to as forged steel gate, forgings materials have A105, F11, F5, 304, 304 l,316, 316 l, etc. Domestic often say forged steel gate valves are normally refers to forged steel gate, small diameter range: DN10 Gate valves work environment.
Forged steel gate valve is suitable for Class150 ~ 2500-29, working temperature to 425 ℃ (carbon steel) or - 29 ~ 500 ℃ (stainless steel) of small diameter pipe, used to truncate or on line in the medium, choose different material, can be respectively suitable for water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea and other media. Applied on the oil pipeline path.
Forged steel gate valve are designed for dalian type reducing, and compared with diameter cast steel gate valves of the flow rate is smaller, but the pressure and temperature range is higher than the cast steel valves, the sealing performance is much better than cast steel gate valves, longer life, the medium flow direction as well as other electric three way control valve is not restricted.
China gate valve installation points
1, installation location, altitude, direction of import and export must comply with the design requirements, should firmly close connection.
2, all kinds of manual valves installed on the thermal insulation pipe, handle down is not allowed.
3, the valve before installing a visual inspection must be conducted. ZhuGanGuan for working pressure is greater than 1.0 MPa and the valve with the function of cutting off, before the installation should be strength and tight performance testing, qualified rear prospective use. Strength test, the test pressure is 1.5 times the nominal pressure, duration of not less than 5 min, shell and packing shall be no leakage of valve shall be qualified. Leak test, the test pressure is 1.1 times the nominal pressure; Test pressure in the duration of the test should comply with the standard of GB 50243 requirements, qualified for damper seal face no leakage.
Forged slab gate valve often ignore the problem of grease injection rate. Note oil, grease gun operator select valves and greasing connection, on the operations. There are two forged steel gate valve: on the one hand, on the quantity is little greasing, sealing surface due to the lack of lubricant and speed up the wear and tear. On the other hand on the excess, resulting in waste. Is that no categories depending on the type of valve, valve sealing capacity of different calculations. Can calculate a seal to the valve size and category capacity, reasonable injection again just the right amount of grease.
Forged steel gate valve often ignore the pressure problem. In the greasing operation, on the pressure gauge half free floating ball type steam trap law changes in peak valley. Or safety valve leakage pressure is too low, seal failure, the pressure is too high, on the lipids within the valve manufacturer jams, seal hardening or sealing ring and valve ball, valve plate lock. Usually fat injection pressure too low, inject grease into the valve at the bottom of the cavity, more commonly occur in the small gate.