All gas fittings and components between the cylinder and the input side of the
gas regulator (which is there to reduce the output pressure of the bottled gas)
are classed as the 'high pressure' side of the gas system. Damage here could
cause a very rapid and significant burst of gas to escape. To reduce the
chances of this gas reaching the interior of your boat these high pressure
components must be installed in one of the following locations:

• on the open deck
• cabin top
• outside the cockpit
• in a cylinder locker
• in a cylinder housing.

Where two or more cylinders are connected, each high pressure connection
must be protected by a non-return valve. This will prevent a high pressure leak
occurring when one of the two cylinders is disconnected.

It may not always be obvious whether you have a non-return valve. Most
automatic changeover devices will have them, some double wall blocks
incorporate them and some pigtails are supplied with them. If you have any
doubts about this please consult a gas professional or contact the BSS office.

If a high pressure LPG hose breaks or leaks this could flood your boat with LPG, even if that side of the system is kept on deck or in a locker. To minimise the risk
of this happening high pressure components, which are not directly attached to
the cylinder valve, must be connected by a pre-assembled length of flexible hose
conforming to Type 2 of BS 3212 (or the equivalent European Standard for
hose, BS EN 1763) and must be fitted with integral threaded metallic ends. You
can always check with the BSS office. To allow for the replacement of cylinders
the flexible hose must be of the minimum practical length and not exceed
1m (3ft 3ins).

High pressure components, e.g. the regulator, that are not directly attached to the
cylinder valve must be secured in a position that provides protection from
mechanical damage and protects vent holes from getting debris or water in them.
Your LPG appliances operate within a certain pressure band and above this level
the flame on an appliance may roar and lift off, which could ignite nearby fuel or
vapour. Below this level the appliance burner may go out, allowing gas to leak
into your boat. To minimise the risk of either of these things happening,
regulators with a manual pressure adjustment facility must not be fitted. This will
prevent LPG at incorect pressures from reaching appliances.

Regulators do not last forever and the British Standard BS 5482-3
recommends that regulators more than ten years old should be replaced. [7.10]