ISO 8434-3:2005规定了外径为6 mm至38 mm（含6 mm至38 mm）的管或软管用钢制O形圈端面密封接头的设计和性能的一般要求和尺寸要求。这些连接器用于流体动力和一般应用中，在这些应用中，可以使用弹性密封件来防止流体泄漏，包括由装配程序变化引起的泄漏。它们用于按照ISO 6149将管道和软管配件连接至端口- 1.可以通过更换套筒来调节公制和英制管道。过去，这些连接器主要用于英制管道。对于新的和未来的设计，最好使用公制管道。 ISO 8434-3:2005还规定了O形密封圈端面密封接头的性能和鉴定试验。

ISO 8434-3:2005 specifies the general and dimensional requirements for the design and performance of O-ring face seal connectors made of steel for tube outside diameters or hose inside diameters of 6 mm through 38 mm, inclusive. These connectors are for use in fluid power and general applications where elastomeric seals can be used to prevent fluid leakage, including leakage caused by variations in assembly procedures. They are intended for the connection of tubes and hose fittings to ports in accordance with ISO 6149-1. Both metric and inch tubing can be accommodated by changing the sleeve. In the past, these connectors have been used predominantly with inch tubing. For new and future designs, the use of metric tubing is preferred. ISO 8434-3:2005 also specifies a performance and qualification test for O-ring face seal connectors.