Spirax Sarco spiraxsarco shutoff valve bellows seal with a unique design that completely eliminates stem packing seal leakage problems, meet the most stringent requirements for leakage rating. spiraxsarco steam stop valve diameter from DN15-DN250, can provide a variety of different materials, from cast iron BSA1, BSA2 and BSA3 type shutoff valve connection standard ductile iron cast steel flanged, threaded and socket welding , pressure rating up to PN40, ANSI 300 and CLASS 800. The maximum operating temperature can be 425C °, can be used for high-temperature system. A valve can be used in order to meet the requirements of various industrial applications, and to ensure a long service life, maintenance-free and robust and strong. Applicable conditions: 1, 2 steam and condensate, process fluid 3, 4 hot and cold water systems, hot oil system 5, 6 chemical fluids, toxic fluids 7, 8 compressed air and other gases, water / glycol and other industries Spirax Sarco steam SpiraxSarco fluid shutoff valves are forced closed valve, so when the valve is closed, the pressure must be applied to the valve to force the sealing surface does not leak. When the medium consists of the bottom valve into the valve, the operating force required to overcome the resistance, frictional force and the thrust generated by the pressure medium and the valve stem packing, the valve off the valve opening force larger than the force, so that the stem The diameter should be large, otherwise the stem top corner of the fault will occur. In recent years, from the emergence of self-sealing valve, globe valve medium flow into the valve chamber to change the valve from the top, then under media pressure, the valve off a small force, and force open the valve, the valve stem diameter can be reduced accordingly. Meanwhile, under the effect of the medium, this form of valve is also more closely. About Spirax Sarco Spirax Sarco (spiraxsarco) history can be traced back to 1888 ,, 1937 built the site in English Cheltenham, the company is a world leader in steam engineering systems, is committed to effectively use and control of steam, hot water, compressed air and other industrial fluids. Its presence in China began in 1993, and in 1995 set up a wholly-owned subsidiary in China.