Installation pipework made of unsuitable materials may fail, leading to gas leaks.
Installation pipework must be made of either of the following:

• seamless copper tube which conforms to BS EN 1057 with copper or
• copper alloy compression fittings
• stainless steel tube or copper nickel alloy of a grade suitable for use with LPG in a marine environment with appropriate compression or screwed fittings.

Flexible hose can be used to connect the installation pipework to a gimballed
cooking appliance, or a domestic cooker or refrigerator, that needs to be moved
for cleaning. A gimballed appliance is one which is fixed on swinging mounts,
allowing it to compensate for the boat's movement. If a flexible hose is used it
must conform to Type 2 of BS 3212.

If there's only a single cooking appliance installed on your boat, flexible hose
can be used to connect it directly to the low pressure regulator. As flexible hose
can and will deteriorate in time, its use must be kept to a minimum and its
individual length should not exceed 1m (3ft 3ins). [7.12]