原文：
国内生产安全阀的厂家比较多，连接尺寸也大多不统一。主要分以下几个大类： 　　（1）以JB／T2203－1999《弹簧式安全阀结构长度》为主的通用类。目前国内大多数安全阀生产厂家均按本标准设计生产。如浙江罗浮锅炉附件厂、杭州阀门厂、江苏吴江阀门工具厂、上海阀门厂、开封高压阀门厂、海安阀门厂等。但本标准也不尽xx，规格不全，微启式安全阀{zd0}公称通径为 D NI 00，全启式安全阀{zd0}公称通径DN200，中间缺少DN65、DN125两个规格。根据我厂所生产的安全阀规格及掌握的资料来看，目前微启式安全阀公称通径{zd0}达到DN250，全启式安全阀公称通径达到DN400。经本人考证，各厂家连接尺寸也不尽统一，如 DN150全启式安全阀，浙江罗浮锅炉附件厂、上海阀门厂及江苏吴江阀门工具厂各不相同。为了有一个统一的标准，用户在选用及安装时同一规格能够互换，建议合肥通用机械研究所对JB／T2203－1999《弹簧式安全阀结构长度》进行修订。 建议设计院及用户按标准选用，安全阀生产厂家按标准设计制造。 　　（2）以API526 《钢制法兰连接安全泄放阀》（Flanged Steel Safety Relief Valve）为主的美标体系。国内进口化工设备等所配的安全阀连接尺寸一般按照本标准，如图5所示。本标准公称通通径为DN25~ DN200（ l”~ 8”），公称压力为 2~ 42MPa，喉径从D－T（9．5~146mm）。本标准比较科学规范，对压力、材料、温度、喉径等统筹考虑。依照喉径确定规格，同一喉径可以有好几个规格，相反同一规格可能有好几个喉径可以选择。如 DN100~DN150（4”~6”）喉径有L、M、N、P四种可以选择。随着国际贸易及进口设备国产化的不断推进，该标准将在国内得到很大推广。目前该标准还没有转化为国标。 　　（3）以在国际上影响比较大的安德森·格林伍德公司（Anderson Greenwood＆Co．）为依据的活塞式导阀操作安全泄压阀（Pilot Operated Pressure Relief Valves）系列。国内一般称之为先导式安全阀，如图6所示，先导式安全阀由主阀和导阀组成，导阀操作主阀的开启和关闭。这种阀门排量大；不受背压的影响；可以在非常接近开启压力下进行不泄漏操作；启闭压差小等优点。一般适用于天然气管道等。目前国内还没有先导式安全阀标准及连接尺寸标准。并且这种类型的阀门刚刚开发，还没有广泛推广。据我厂的经验及所掌握的资料来看，国内大多数厂家按照该公司的数据设计制造，如浙江罗浮锅炉附件厂、航天十一研究所等。建议合肥通用机械研究所尽早起草并发布先导式安全阀标准。 　　（4）以兰州炼油厂设计研制开发的A型、TA型封闭全开启弹簧式安全阀自成一个体系。该系列口径DN25~DN150 （1”~6’），公称压力l．6~4.0MPa，喉径D~R（9．5－115mm）。该体系连接尺寸与美标及国标均不相同，为兰炼专用。 　　（5）为锅炉、电站设备、减温减压装置配套的冲量式安全阀系列（如图8所示）。如哈尔滨锅炉厂、东方锅炉厂、武汉锅炉厂、青岛电站辅机厂等配套的专用安全阀。此类系列阀门结构及连接尺寸各厂家一般不相同，可能有部分相同。选用时一定要注意阀门喉径及连接尺寸的区别。 　　（6）以中国航天工业总公司第十一研究所设计研制的安全阀自成一个体系。航天十一所研制的HT系列安全阀品种多，有HTO普通安全阀（如图1所示）、HTB平衡波纹管式安全阀、HTR泄流阀、HTN特殊安全阀、HTGS高性能蒸汽安全阀。ＨＴＸＹ液体泄压阀、HTXD先导式安全阀等，且性能良好。但是除HTXD系列先导式安全阀与安德森·格林伍德公司连接尺寸相同外，其余与美标、国标均不相同。这一点请选用时务必注意。

“ Select safety valve should be noted that the problem ”是由提供的国际阀门新闻，译文仅供参考。另外，中国安全阀网还提供相关产品搜索： 、 、 、 、 等。

译文：
Safety valve manufacturers of domestic production are more connected mostly non-uniform size. Mainly consists of the following categories: (1) JB/T2203-1999 "spring-loaded safety valve structure, length," based utility category. Currently most of the safety valve manufacturer designed and manufactured in accordance with this standard. Rover Boiler Accessories Factory, Zhejiang, Hangzhou valve factory valves tools plant in Wujiang, Jiangsu, Shanghai Valve Factory, Kaifeng High Pressure Valve Factory, MSC valve factory. But the standards are not perfect, incomplete specifications, Weiqi safety valve for the nominal maximum diameter D NI 00, the largest safety valve nominal diameter DN200, among the lack of DN65, DN125 two specifications. According to my safety valve manufactured specifications and information available at this moment Weiqi safety valve to achieve the maximum nominal diameter DN250, safety valve nominal diameter to DN400. After my research, the manufacturers are not the unified connection dimensions, such as the safety valve DN150, Zhejiang Rover Boiler Accessories Factory, Shanghai and Jiangsu Wujiang valve factory valves tools plant vary. In order to have a unified standard, users choose and install in the same specification to exchange, recommendations, Hefei General Machinery Research on JB/T2203-1999 "spring-loaded safety valve structure of length" be revised. Proposed institute, and the user selected standard, the standard safety valve manufacturers design and manufacture. (2) API526 "flanged steel safety relief valve" (Flanged Steel Safety Relief Valve)-based American Standard system. China imported chemical equipment with safety valve connection sizes are generally in accordance with the standards shown in Figure 5. Tone of the standard nominal diameter DN25 ~ DN200 (l "~ 8"), nominal pressure for the 2 ~ 42MPa, throat diameter from D-T (9.5 ~ 146mm). Comparison of the standard scientific norms, pressure, material, temperature, throat diameter and so overall consideration. Throat diameter determined in accordance with specifications, the same throat diameter can have several specifications, the opposite may be the same size pipe diameter can choose several. If DN100 ~ DN150 (4 "~ 6") diameter pipe with L, M, N, P 4 kinds to choose from. As international trade and import of equipment made continuous progress, the standard will be expanded greatly in China. Currently the standard has not yet translated into national standards. (3) the relatively large influence in the international Anderson Greenwood Company (Anderson Greenwood & Co.) Based on the safe operation of pilot valve piston pressure relief valve (Pilot Operated Pressure Relief Valves) series. Domestic commonly known as pilot safety valve, as shown in Figure 6, the pilot safety valve from the main valve and pilot valve composition, operation of pilot valve opening and closing the main valve. This valve displacement large; from the impact of back pressure; can be very close to not leak under pressure to open operation; opening and closing pressure difference and so on. Generally applicable to natural gas pipelines. Currently no standards and pilot safety valve connection size standards. And just this type of valve development, no widely. According to my factory experience and the available information shows that most domestic manufacturers in accordance with the design and manufacture the company's data, such as boiler accessories factory Zhejiang Rover, Space Research Institute 11. Hefei General Machinery Research Institute proposed as early as possible to prepare and publish standard pilot operated relief valve. (4) design developed by the Lanzhou Oil Refinery A-type, TA-type closure of all open the spring-loaded safety valve independent system. The series bore DN25 ~ DN150 (1 "~ 6 '), nominal pressure l.6 ~ 4.0MPa, throat diameter D ~ R (9.5-115mm). The system to connect with the American standard size and national standard are not the same as Lan Lian-specific. (5) for boilers and power station equipment, temperature and pressure reduction devices supporting the impulse-type safety valve series (shown in Figure 8). Such as the Harbin Boiler Works, Dongfang Boiler Factory, Wuhan Boiler Factory, Qingdao Power Station Auxiliary Equipment Works, and assorted special safety valve. Structure and connections of such series valves are generally not the same size of the factory, there may be some of the same. Selected must pay attention to the valve and connecting pipe diameter size difference. (6) The 11th Institute of China Aerospace Industry Corporation designed and developed an independent system safety valve. Space 11 Series valve developed by HT varieties, there HTO general safety valve (Figure 1), HTB balanced bellows safety valve, HTR discharge valve, HTN special safety valve, HTGS high-performance steam safety valve . HTXY liquid pressure relief valve, HTXD pilot operated safety valves, etc., and good performance. But apart from HTXD series pilot operated relief valve connected with the Anderson Greenwood companies the same size, the other with the American standard, national standard are not the same. This is important to note, please select the time.