Comparison of main domestic safety valve manufacturers and selection of connection size

Comparison of main domestic safety valve manufacturers and selection of connection size; there are many domestic safety valve manufacturers, and most of the connection sizes are not uniform It is mainly divided into the following categories: (1) the general category based on JB / t2203-1999 structural length of spring safety valve At present, most domestic safety valve manufacturers are designed and produced according to this standard However, this standard is not exhaustive and the specifications are not complete The large nominal diameter of the micro lift safety valve Zui is DNI 00, the large nominal diameter of the full lift safety valve Zui is DN200, and there are two specifications of DN65 and DN125 in the middle According to the specifications and data of safety valve produced by our factory, at present, the nominal diameter of micro lift safety valve Zui is up to DN250, and the nominal diameter of full lift safety valve is up to dn400 Through my research, the connection sizes of various manufacturers are not uniform, such as DN150 full open safety valve, which are different In order to have a unified standard, users can exchange the same specification in selection and installation, it is suggested that Hefei General Machinery Research Institute revise JB / t2203-1999 structural length of spring safety valve It is suggested that the design institute and users should select according to the standard, and the safety valve manufacturer should design and manufacture according to the standard (2) American Standard System Based on api526 steel flange safety relief valve The connection dimensions of safety valves for domestic and imported chemical equipment are generally in accordance with this standard, as shown in Figure 5 The nominal diameter of this standard is DN25 ~ DN200 (L "~ 8"), the nominal pressure is 2 ~ 42MPa, and the throat diameter is from D-T (9.5 ~ 146mm) This standard is more scientific and normative, and takes pressure, material, temperature and throat diameter into consideration as a whole According to the throat diameter to determine the specifications, the same throat diameter can have several specifications, on the contrary, the same specification may have several throat diameters to choose For example, there are four options for the throat diameter of dn100-dn150 (4 "~ 6"): l, m, N and P With the continuous promotion of international trade and the localization of imported equipment, the standard will be greatly promoted in China At present, the standard has not been converted into a national standard (3) the series of pilot operated pressure relief valves based on Anderson Greenwood & Co., which has great influence in the world Generally known as the pilot safety valve in China, as shown in Figure 6, the pilot safety valve consists of a main valve and a pilot valve, which operates the opening and closing of the main valve This kind of valve has the advantages of large displacement, no influence of back pressure, no leakage operation under very close opening pressure, small opening and closing pressure difference, etc Generally applicable to natural gas pipeline, etc At present, there is no standard of pilot safety valve and connection size in China And this type of valve has just been developed and has not been widely promoted According to our experience and data, most domestic manufacturers design and manufacture according to the company's data (4) a safety valve system designed and developed by the 11th Research Institute of China Aerospace Industry Corporation There are many kinds of HT series safety valves developed by aerospace 11 Institute, including HTO general safety valve (as shown in Figure 1), HTB Balanced Bellows Safety valve, HTR relief valve, HTN special safety valve and HTGS high performance steam safety valve Htxy liquid pressure relief valve, htxd pilot safety valve, etc., with good performance However, except for htxd series pilot safety valve with the same connection size as Anderson Greenwood company, the others are different from American Standard and national standard Please pay attention to this when selecting (5) a type and Ta type closed full open spring safety valve designed and developed by Lanzhou Refinery is a self-contained system This series has a diameter of DN25 ~ DN150 (1 "~ 6 '), a nominal pressure of l.6 ~ 4.0Mpa and a throat diameter of D ~ r (9.5-115mm) The connection size of the system is different from the American Standard and the national standard, which is special for Lan Lian (6) impulse safety valve series (as shown in Figure 8) for boiler, power plant equipment, temperature and pressure reducing device Such as Harbin boiler plant, Dongfang Boiler Plant, Wuhan boiler plant, Qingdao power station auxiliary equipment plant and other supporting special safety valves The structure and connection size of these series of valves are generally different from each manufacturer, and some of them may be the same When selecting, pay attention 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