These brass fixed pressure regulating valves are ideal for systems which require reduced & regulated pressure, like drip irrigation systems. For areas with high pressure. Plastic pressure reducers can't handle constant high pressure so the benefit with a brass pressure regulator is that you can put one on at the water connection for a drip irrigation system rather than one plastic pressure reducer on each zone. Please note the pressure regulators that do not come with a check valve, and may not be suitable for use with caravans. The pressure regulator including a check valve has been designed for use in caravans.