Steam trap in steam heating system to play the role of gas drainage, select the appropriate trap, the steam heating equipment to achieve maximum efficiency. In order to achieve the best results, we must conduct a comprehensive understanding of the performance of various types of traps, features. Trap a lot of varieties, each with different properties. Trap selection, first of all should be selected to meet the characteristics of steam heating equipment, the best operation, and then consider other objective conditions, this choice is the right trap and effective. Traps to be able to "identify" steam condensate water, in order to play the role of blocking gas drainage. "Identify" steam condensation water is based on three principles: density difference, temperature differential phase change. So on the basis of three principles to create three types of traps, classified as mechanical, thermal static, thermodynamic. First, the mechanical type trap Mechanical type, also known as the float type, is the use of condensed water and steam density difference, through the condensate level changes, so that the float lift valve to open or close, to block steam drainage purposes. Mechanical type of small degree of supercooling traps, free from pressure and temperature changes, who is Pai, heating equipment without water, can make the heating equipment to achieve the best heat transfer efficiency, the maximum back pressure rate of 85% , The quality of work, is the production process of heating equipment, the best trap. Mechanical trap with free float, free half float, lever float, inverted bucket, bell float, etc. ----- 1. Free Float Traps: Free Float Traps The structure is simple, there is only a fine grinding stainless steel hollow float, which is the float and the opening and closing pieces, non-wearing parts, long service life, "Silver Ball" Free Float Traps with automatic row Air plant, very sensitive, high quality work. Free float ball valve seat is always below the liquid level to form a water seal, no steam leaks, energy-saving effect. Free float ball traps from temperature and pressure fluctuations in the work of continuous drainage. Saturated temperature to condensate water can be discharged, the heating equipment without water, can make the heating equipment to achieve the best heat transfer efficiency, the back pressure rate is greater than 85%, is the production process heating equipment, one of the best trap. 2. Free half-float trap: Free half-float trap is only a semi-floating ball bucket for the moving parts, opening down, the bucket is the opening and closing pieces, but also seals, resistant to water Click, no wearing parts, trouble-free, durable, no steam leaks. The back pressure rate is greater than 85%, to the saturation temperature of condensate water, the minimum undercooling is 0 ℃, heating equipment without water, can make the heating equipment to achieve the best heat transfer efficiency. 3. Lever float trap: Lever float trap the basic characteristics of the same with the free float, the internal structure of the float lever connected to the valve spool, with the condensation of the liquid level switch valve. Leveraged float traps use double seats to increase condensate displacement to achieve large volumes for large displacement. Leverage float trap maximum hydrophobic capacity of up to 65 tons / hour, is the ideal large-scale heating equipment trap. 3. inverted bucket trap (bell-type float): inverted bucket traps inside is an inverted bucket for the level of sensitive parts, buckets opening down, inverted bucket connected to the valve lever to open the valve. Upside down bucket traps can drain air, not afraid of water hammer, low degree of supercooling, the maximum back pressure rate of 85%, intermittent drainage. Second, the thermostatic trap This type of trap is the use of steam and condensate temperature difference caused by temperature deformation or expansion of the valve element valve opening and closing. Subcooling of thermal-static trap is relatively large, the general degree of subcooling is 15 degrees to 40 degrees, it can make use of part of the heat of condensation water, the valve always has high temperature condensate, no steam leakage, energy-saving effect was significantly With Thermostatic trap with a membrane box, bellows, bimetallic ----- 1. Diaphragm-type trap: diaphragm-type trap main action element is a metal diaphragm, the diaphragm charge There is a vaporization temperature lower than the saturation temperature of water, the valve temperature is lower than the saturation temperature of 15 ℃ and 30 ℃ are two options. The membrane trap is particularly sensitive, not afraid of freezing, small size, overheating, can be installed anywhere, the back pressure rate is greater than 70%, can row non-condensable gas, membrane box, long life, easy maintenance, use A wide range. 2. Bellows Traps: Bellows Traps Stainless steel bellows filled with a vaporization temperature below the water saturation temperature of the liquid. With the steam temperature change control valve switch, the valve is equipped with adjusting bolts, adjust the use of temperature as needed, the general range of subcooling is below the saturation temperature of 15 ℃ -40 ℃, back pressure greater than 70%, not afraid of freezing, small size, Installed anywhere, can row non-condensable gas, long service life. 3. Bimetallic trap: The main component of the bimetallic trap is the bimetallic temperature sensing element, which is heated and deformed with the rise and fall of the steam temperature to promote the valve opening and closing. Bimetallic traps with adjusting bolts can be adjusted according to the need to use the temperature, the general range of subcooling is below the saturation temperature of 15 ℃ -10 ℃, the back pressure rate is greater than 70%, can row non-condensable gas, not afraid of freezing, Small size, resistant to water hammer, high pressure, can be installed anywhere. Bimetal fatigue, need to be adjusted often. Third, the thermodynamic steam trap This type of trap according to the phase change principle, by the steam and condensate flow through the flow rate and volume changes in different thermodynamic principles, the valve pressure difference up and down to drive the valve switch valve. Due to the work force of the thermodynamic steam trap comes from the steam, steam is more wasteful. Simple structure, water hammer, maximum back is 50%, noisy, frequent valve work, short service life. Thermodynamic steam traps have thermal power (disc), pulse type, orifice plate type ----- 1. Thermodynamic Traps Thermodynamic steam trap has a valve activity, both sensitive and action Executive pieces. According to the different thermodynamic principles of flow rate and volume change when the steam and condensate pass, the pressure difference is generated on the valve plate to drive the valve switch valve. National standards for qualified products for the 3% -5% leak rate, undercooling of 8 ℃ -15 ℃, intermittent drainage, the maximum back pressure of 50%, no noise, frequent valve disc, short service life. 2. Disc steam insulation trap: Disc steam insulation trap works the same as with the thermodynamic steam trap, it is outside the steam chamber in the thermodynamic steam trap to add a layer of shell. The inner chamber of the shell and the steam pipe are communicated with each other, and the main steam chamber of the steam trap is insulated by the steam of the pipe itself. So that the temperature of the main steam room is not easy to cool, keep the steam pressure, trap tightly closed. When the pipeline produces condensate, trap shell cooling, traps began to drain; superheated steam pipeline if there is no condensation of water, the trap will not open, high quality work. The valve body is made of alloy steel and the valve core is made of cemented carbide. The maximum allowable temperature of the valve is 550 ℃. It is durable and has long service life. The valve is specially designed for high pressure, high temperature and superheated steam. 3. Pulse trap: pulse trap has two orifice, according to changes in steam pressure to adjust the valve switch, even if the valve is completely closed the entrance and exit through the first and second holes are connected, always in the incomplete closure State, the steam overflow, a large amount of air leaks. The trap action frequency is high, wear powerful, shorter life expectancy. 4. Trap trap: Trap trap is based on different displacement, choose a different aperture of the orifice, to control the purpose of paishuiliang. Simple structure, inappropriate choice will appear less than or a large number of running water dredging, does not apply to intermittent production of steam equipment or condensate water volume fluctuations in the use of steam equipment.