You must replace any single stage regulator with a 2 stage regulator on a caravan - you can keep using your single stage reg - but if you need to replace it the Law requires you to use a 2 stage reg.
The Marshall reg is a very reliable unit and is the only one we will use in our workshop.
Single-stage gas pressure regulators reduce the cylinder pressure to the delivery pressure in one step, where a two-stage gas pressure regulator accomplishes the same thing with two stages of pressure reduction. This means that a single-stage regulator has to be adjusted to maintain a constant pressure as the gas in the cylinder is used, but a two-stage regulator does not. Two-stage regulators are typically used when more stability of operation is required and are often used in specialty gas applications, like gas chromatography. BBQ, BBQ spares, Gas, Gas Heater Parts, Marshall