Installation pipework must be fixed away from, or insulated against, electricity or telecommunication services and must not pass through the same duct as these other systems. It must be separated from uncovered electrical cables by at least 30mm (1.2ins). It's also recommended that installation pipework does not pass through ventilation or air conditioning ducts located on your boat.
Deterioration of pipework could occur if it's subjected to water damage. To reduce the chance of this happening it's a good idea to keep pipework away from water services.
The effect of heat on pipework can cause it to expand and contract, which can lead to a hardening of the pipework or loose joints, which in turn could allow gas to escape. To help prevent this happening, installation pipework must be positioned at least 75mm (3ins) away from exhaust pipes or other sources of heat. [7.18]