This part of ISO 5175 specifies the general requirements and tests for decomposition blockers for acetylene downstream of pressure regulators in manifold systems. Decomposition blockers can be used in the low pressure section up to 0,15 MPa (see ISO 14114) e.g. in pipelines, outlet points or for the protection of low pressure sections in big pipe systems. Decomposition blockers can only be used in sections with pure acetylene. The possible backflow of oxygen or air into the section there the decomposition blocker is installed, must be prevented by a non-return valve, downstream of the decomposition blocker.