Safetygram-31安全程序-31Cylinder Valve Outlet Connections钢瓶阀门排气口接头Introduction引言The Connections Standards Committee of the Compressed Gas Association (CGA) is responsible for assigning standard connections for specific gases and establishing detailed dimensions for the manufacture of these connections. The main purpose for establishing such standards is to prevent interconnection with non-compatible gases and to provide continuity among manufacturers. Assigned connections also prevent interconnection of the same gas at incompatible pressures. 压缩气体协会（CGA）的接头标准委员会负责为特殊气体指定标准接头和为这些接头的制造确定详细的尺寸。建立这些标准的主要目的是防止不相容气体的相互连接和在制造商之间提供连续性。指定接头还防止了在不相容压力下同样气体的交叉连接。There are four basic groups of valve outlet connections: (1) connections for general, industrial compressed gas service; (2) connections for self-contained breathing apparatus (SCBA) service; (3) connections for ultra-high-integrity service; and (4) pin-indexed connections for medical gas service. Although this Safetygram addresses connections only for industrial compressed gas service and ultra-high-integrity gas service, much of this information also applies to the other two groups. 有四组基本的阀门排气口接头：(1) 用于普通的工业气体设施的接头；(2)用于自给式呼吸器（SCBA）装置的接头； (3)用于超高完整性装置的接头；和(4)用于医疗气体设施的指度针接头。尽管本安全程序只说明用于工业压缩气体设施和超高纯度气体设施的接头，这些资料中的许多也适用于其它两组接头。In North America, outlet connections are usually designated by a three-digit number preceded by the letters CGA, the acronym for the Compressed Gas Association, for example, CGA 350. Sometimes an ultra-high-integrity connection is preceded by a “DISS” designation rather than the more common CGA designation. DISS is the acronym for Diameter Index Safety System.在北美，排气口接头通常由在字母CGA之后的三位数字指定名称，例如CGA 350。CGA是压缩气体协会的只取首字母的缩写。有时候超高完整性接头的指定名称的前面是“DISS”，而不是更常用的CGA。DISS是直径指数安全系统的只取首字母的缩写。Typical Connections典型的接头A typical connection consists of three or four parts depending on whether it is a bullet-nose or a gasketed connection. A bullet-nose connection consists of a valve outlet, a nut, and a nipple. The nut is placed on the nipple so the shoulder of the nipple rests against the pushing surface of the nut. The nut has straight threads that engage the mating threads on the valve outlet and pull the nipple against the sealing surface of the valve outlet. No sealing takes place at the threads. The gas-tight seal takes place between the nipple and the valve outlet seat at a very small contact circle where they touch. The success of this connection depends on the surface condition of both the nipple and the valve outlet sealing area at the point of contact. 根据它是弹头接头还是衬垫接头，一个典型的接头由三个或四个零件组成。一个弹头接头由一个阀门排气口、一个螺母和一个管接口组成。螺母放在管接口的上面，因而管接口靠在螺母的螺纹正面。螺母有直螺纹，直螺纹咬合阀门排气口上的配合螺纹，拉动管接口靠在阀门排气口的密封面上。在螺纹上不形成密封。不漏气的密封形成在管接口和阀门排气口座之间，在它们接触的一个非常小的接触圆周处。这种接头的成功依赖于管接口和阀门排气口密封在接触点的表面状况。Some bullet-nose connections have a soft tipped nipple or an O-ring on the nipple to improve the seal. This allows the connection to be made without a wrench, using a nut equipped with a hand wheel. These connections are called hand-tight connections. 一些弹头接头具有一个软头管接口或在管接口上有一个O形圈，以改善密封。这使得不用扳手，而是使用带手轮的螺母就可以进行连接。这些接头称为手紧接头。A gasketed connection has four parts: the valve outlet, a nipple, a nut, and a gasket (or washer).The nipple of the gasketed connection is not bullet-shaped as in the bullet-nose connections, but is flat to compress the gasket. The valve outlet sealing area is also flat. The nut fits on the nipple so the shoulder of the nipple rests on the pushing surface of the nut. The washer is placed on the flat surface of the nipple inside the nut. The straight threads of the nut engage with the mating threads of the valve outlet and are tightened to compress the gasket between the two sealing surfaces. 一个衬垫接头有四个零件：一个阀门排气口、一个管接口、一个螺母和一个衬垫（或垫圈）。衬垫接头的管接口不是象弹头接头那样的子弹形，而是平的，以便压缩衬垫。阀门排气口密封区域也是平的。螺母配合在管接口上，因而管接口靠在螺母的螺纹正面。垫圈放在螺母内的管接口的平面上。螺母的直螺纹同阀门排气口的配合螺纹咬合在一起并上紧，来压缩在两个密封表面之间的衬垫。Standard industrial valve outlet connections are designed to provide a “bubble-tight” connection, which refers to leak-checking the connection with a soap solution or by immersing it in water. Bubbles indicate a leak. Leak detection solutions vary in their ability to detect leaks. However, leakage rates for standard connections range from 1 x 10-3 to 1 x 10-5 cc of helium per second. Slower leak rates can be obtained with these connections depending on surface finishes, gasket materials, and mechanical condition. However, achieving slower leak rates can be difficult and inconsistent, one of the primary reasons why the ultra-high-integrity outlet connections were developed.标准工业阀门排气口接头设计得可以提供一种“不冒泡”接头。这是指用肥皂水溶液或把它浸在水中来对接头检漏。起泡说明有泄露。检漏溶液的检漏能力是不同的。但是，标准接头的泄露率在每秒1 x 10-3 到1 x 10-5 毫升氦范围内。依赖于表面光洁度、衬垫材料和机械状况，用这些接头可以获得更慢的泄露率。但是，获得更慢的泄露率可能是困难和不协调的，这是为什么发展超高完整性排气口接头的一个主要原因。Fig. 1 A typical bullet nose connection.图1 一个典型的弹头接头Fig. 2 A typical gasket connection. 图2 一个典型的衬垫接头Table 1: Torque Recommendations for Bullet Nose Connections 表1 弹头接头的推荐的转矩Valve Material 阀门材料 x Nipple Material管接口材料