Keymark Improves Safety In Gas Applications

A keymark inserted between a quick coupler and a gas-supply hose coupling can improve the level of safety when using acetylene and oxygen, according to Witt. The keymark coupling was originally designed to be used by welders in shipyards to stop serious explosive accidents occurring due to unauthorised use of acetylene and oxygen by other workers. The keymark, which is designed for use with the SK 100 quick hose coupler and hose coupling, is a 5cm-diameter flat ring with three studs that is inserted between the coupler and the hose-coupling connection.

When the keymark is used, the studs are pressed into the coupler when connected to the hose coupling – only then will the gas start to flow. The keymark can be used as a simple-to-use, low-cost safety device for welding applications in many industries that use oxygen, oxy-fuel and inert gases, by being issued to only equipment operators. Keymarks can be individually identified with an individual’s works number or some other identification of those personnel permitted to carry out welding processes.

The SK100 hose couplings meet ISO 7289 standard and are EN 561BAM certified. They prevent uncontrolled escape of gas when disconnected through their automatic cut-off valves, as well as prevent build-up of explosive gas mixtures in the gas-supply pipe due to their non-return valves. Different probes are used for oxygen, oxy-fuel and inert gases, so that the gas being used can only be connected to the correct probe.