Valve Outlet Connections

This section summarizes the uniform American and Canadian standards for compressed gas cylinder valve outlet connections. 

Listed to the right of each of these categories, as applicable, are the Standard, Limited Standard, and Alternate Standard connections for each gas. CGA V-1, American National, Canadian, and Compressed Gas Association Standard for Compressed Gas Cylinder Valve Outlet and Inlet 

Connections, defines small cylinders as those with a capacity less than or equal to 110 in. (1.80 L 1.81 kg water). [1] For a discussion of the valve connections that may be used on such cylinders, which include those termed lecture bottles, readers are referred to CGA V-1 (paragraph 2.8 of the 1987 sixth edition). 

A Standard connection is the recommended connection for a particular gas or gases. A Limited Standard connection is one recommended for a particular gas or gases application where some limitation is imposed on its use. An Alternate Standard connection is one scheduled for obsolescence over a phaseout period, usually five years from the date the Alternate Standard is incorporated into CGA V-1. [1] 

The use of a standard connection is always recommended over an alternate standard to encourage a complete implementation of the changeover during the five-year phaseout period. 

---

Valve outlet connection standardized by the Compressed Gas Association (CGA) (see ref. S). Corrosion of the manual control valve is indicated by sticking on opening and closing, in which case the valve is taken apart and cleaned. 

Figure 4.3 Cylinder parts and markings, (1) cylinder cap (2) cylinder valve wheel to open cylinder (3) valve packing nut, contains a packing gland and packing nut around the valve stem (4) pressure relief device (5) valve outlet connection (6) cylinder collar to which cap is to be attached (7) valve outlet cap, may not be present (8) Specification number shows cylinder conforms to DOT-3AA specifications and design service pressure is 2265 psig 70 F (9) indicates date, month and year first tested. Test is to repeated every 5 years and test date stamped on cylinder. This figure and Figures 4.4 and 4.5 courtesy of Matheson Gas Products.

Container valve connections that do not fit must not be forced. Threads on regulator connections or other auxiliary requirements must match those on the container valve outlet. The valve outlet connection should conform to recognized standards such as ANSI/CGA V-1, American National, Compressed Gas Association Standard for Compressed Gas Cylinder Valve Outlet and Inlet Connections [14]. However, it must be acknowledged that connections other than those found in ANSI/CGA V-1 may exist. If a user chooses such a connection, extreme care must be taken to ensure that such connections do not cross-connect with existing connections in ANSI/CGA V-1, and that they have been properly engineered for the intended gas service and pressure. The threads on a cylinder valve outlet, as well as on regulators and other ancillary equipment, should be examined at frequent intervals to ensure they are clean and undamaged. 

Detailed information regarding compressed gas containers, pressure regulators, pressure relief devices, and valve outlet connections is contained in Chapters 5 through 9. Additional safe handling procedures for compressed gases can be found in CGA P-1 [7], and in CGA AV-1, an audiovisual safety training program of the same title. 

CGA V 7, Standard Method of Determining Cylinder Valve Outlet Connections for Industrial Gas Mixtures, 3 " ed., Compressed Gas Association, Inc., 1725 Jefferson Davis Highway, Arlington, VA 22202. 

Cylinder valve outlet connections fall into four basic designs ... 

STANDARD CYLINDER VALVE OUTLET CONNECTION FOR PRESSURES UP TO 3,000 psig (20 680 kPa) FOR Oxygen... 

Fig. 9-1. Dimensional drawing from CGA V-1—1994 of Connection CGA 540, a standard valve outlet connection.

Since new connections and changes affecting existing connections may occur periodically, it is strongly recommended that the reader obtain the latest editions of CGA V-1 and V-7 [1, 2]. Whenever in doubt, contact CGA for assistance in selecting the proper cylinder valve outlet connections. 

The adequacy of these connections has been demonstrated through their extensive safe use since 1959 when they were first approved by CGA. CGA E-7, American National and CGA Standard for Medical Gas Regulators and Flowmeters, was first published in 1983 [6]. This CGA standard specifies that, where applicable, connections to these components be in accordance with CGA V-5 [5]. The DISS concept formed the basis for the new series of high pressure, ultra-high integrity cylinder valve outlet connections for electronic gases. 

For mixtures, other than those listed in V-1 (medical), CGA V-7, Standard Method of Determining Cylinder Valve Outlet Connections for Industrial Gas Mixtures should be consulted. This publication, through the use of a rating system, takes into account flammability and toxicity in the selection of the recommended outlet connection. Two additional publications, CGA P-20, Standard for the Classification of Toxic Gas Mixtures and CGA P-23, Standard for Categorizing Gas Mixtures Containing Flammable and Nonflammable Components should also be consulted. 

In selecting valve outlet connections for cylinders, it should be noted that end use (medical, industrial, semiconductor), DOT specification, fill pressure, and lading are some of the parameters that must be taken into consideration. Additionally, knowledge of the FTSC coding system is essential. For further information on outlet connections, consult Chapter 9 of this handbook, and for specific assignments see Table 9-1 of that chapter. 

Refer to the introduction to Part II for information on valve outlet connections. A full listing of valve connection assignments for compressed gases in cylinders can be found in Chapter 9, Table 9-1. 

Chlorine is authorized for shipment in ton containers with 2000-lb (907-kg) capacity that comply with DOT specification 106A500X. The pressure relief device is a fusible plug. These are installed on each end of the container. Ton containers conforming to older specifications may still be used. Valve outlet connections are the same as for cylinders except the ton container... 

---