How To Select The Correct Regulator & Gas Hose

Which pigtail or regulator do you need for your caravan, camper trailer or motorhome? This guide explains the main parts in plain language so it is easier to identify what you have before ordering replacement parts.

Your RV gas cylinder holds gas under high pressure. That pressure must be reduced by a regulator before gas is circulated to the low pressure appliances in your RV.

Gas work can be dangerous. Replacement parts must match the existing approved installation, and any gas installation, alteration, leak, regulator replacement or compliance work should be handled by a licensed gas fitter.

1. Pigtails

Pigtails are the hoses or copper pipes that carry gas from the cylinder to the regulator. Because they are before the regulator, they carry high pressure gas and must be rated for that use. All pigtails shown on CaravansPlus are rated for high pressure gas.

(a) Copper pipe can last a long time, but continued bending can fatigue the copper and rough handling can kink it.

(b) Rubber hose with stainless steel braiding has been common in the past. Over time, rubber can break down and particles can contribute to premature regulator failure.

(c) S-Core has a flexible corrugated stainless steel inner tube covered with stainless steel braiding and a protective yellow plastic outer skin. It is flexible, resists normal kinking, and does not have rubber inside the gas line.

(e) shows the two possible threads that connect to the regulator. This is where a lot of confusion starts, because the thread can be hard to identify when you only have the hose in your hand. Colour, such as brass or zinc plating, does not identify the thread.

The NPT thread goes directly into the regulator, so it is generally used when one cylinder is attached. The inverted flare usually goes into a two-way valve where two cylinders are used. The exception is where an adaptor transforms the inverted flare to the NPT thread. Thread tape or liquid seal should only be used where the fitting type requires it.

(f) shows different cylinder fittings. Older installations may use POL fittings, while newer Australian gas cylinders and appliances increasingly use LCC27 connections. Match the pigtail to your cylinder valve and regulator setup, and check the current product description before ordering.

2. Regulators

Regulators can be single stage or two stage. Old caravans may still have a single stage regulator, but for new installations, or where a two stage regulator is being replaced, use the correct two stage regulator. A two stage regulator gives more even final pressure and better appliance performance.

(a) shows a two stage regulator that can be used with a single gas cylinder, or with a valve so you can manually select between two cylinders.

(b) shows an automatic two stage regulator that directly accepts pigtails with 1/4" inverted flare thread.

Regulators must be mounted to a rigid mounting with the diaphragm vertical and the vent pointing downwards.

3. Test points

Test points are mandatory in some states, so CaravansPlus recommends they be included in upgrades. They allow a gas fitter to test that the regulator is functioning correctly.

If gas is leaking from a test point, regulator, hose, cylinder connection or gas locker, turn off the gas cylinder if it is safe to do so, ventilate the area, avoid ignition sources and have the system checked by a licensed gas fitter.

Shown below as ID-12106 and ID-12107, the test points are identical where they connect to the regulator outlet but suit different copper pipe diameters. The correct flared nut should also be selected.

4. Custom regulator kits

If the regulator kits we have available do not suit, the following images can help identify the individual parts needed for a custom kit. This allows for different pigtail hose lengths, hose grades, cylinder connections and copper pipe sizes.

Using the diagrams and pigtail descriptions above, you can identify the parts needed, then use the category links below or search by ID number.

1. Select the pigtail length and style.
2. Select the regulator, test point and change-over valve.

5. Gas safety and common questions

Can I connect an external cooktop with a simple hose?

Portable outdoor appliances and fixed RV gas installations are treated differently. Do not join hoses and regulators together by guesswork. Use the hose/regulator specified for the appliance, and have any fixed caravan gas installation designed and checked by a licensed gas fitter.

Why is an S-Core pigtail not always suitable for a single cylinder?

The hose material is only one part of the choice. The end fittings and regulator connection must also suit the installation. Some S-Core pigtails are made for two-cylinder changeover setups with inverted flare connections, while a single-cylinder regulator may need a different regulator-end thread.

How often should regulators or hoses be replaced?

There is no single visual rule that covers every installation. Replace damaged, cracked, leaking, out-of-date or suspect hoses and have older regulator systems inspected. If you do not know when a regulator or gas hose was last replaced, a licensed gas fitter can pressure-test and advise what should be renewed.

What if I smell gas?

Turn off the cylinder if safe, do not use flames or switches, ventilate the area and get the system checked. A persistent gas smell in a cylinder locker is not normal maintenance; treat it as a fault.