2.9.9 Jointing compounds and materialsJointing compounds and materials shall be fit for purpose.2.10 Hose assemblies2.10.1 GeneralHose assemblies shall be of a minimum practicable continuous length and installed so that —(a) they are protected from exposure to ultraviolet light; and(b) the possibility of damage by rodent attack is minimized.2.10.2 Use of a hose assemblyIn general, other than for hose assemblies between cylinders and regulators, hose assemblies shall be used only between the regulator and rigid piping, and between rigid piping and appliances. Flexible hose shall be one continuous length and as short as practicable for the intended application in order to prevent kinking and damage to the hose. Flexible hose inside a caravan or boat shall be accessible. The connection of hose assemblies to each other is not permitted.For caravans with a slide out section (e.g. for additional living space), a hose assembly is permitted between the rigid piping of a caravan and the rigid piping of the slide out section.Where the flexible hose is concealed (e.g. behind an accessible panel), information shall be supplied with the caravan instructions that state its location and the need for regular inspection by a competent person.NOTE For boats, hoses may be used for a one-appliance installation as corrosion considerations would favour such installation.2.10.3 Hose assembly — Operating conditionsA hose assembly shall not be installed where, under normal operating conditions, it is —(a) exposed to a temperature exceeding the maximum temperature specified in the hose manufacturer’s instructions;(b) subject to stress, abrasion, kinking or permanent deformation; or(c) subject to damage by vermin.2.10.4 Hose assembly connecting an applianceA hose assembly for an appliance shall be —(a) permanently connected to the appliance by a threaded or other metal connection; and(b) permanently connected to the piping by a threaded or other metal connection.2.11 Shut-off valvesShut-off valves, whether manual or automatic, shall be fit for purpose.2.12 Quick-connect devices2.12.1 GeneralA quick-connect device shall be installed so as to avoid entry of water, dust or other debris