What are the Common Types of Propane Fittings Used on RVs?

RV propane systems use a number of different fitting types. The fittings that may be found within a camper's propane setup are Type 1, or ACME, fittings, POL fittings, Disposable Cylinder Port fittings, Inverted Flare fittings, National Pipe Thread fittings, Quick-Disconnect fittings, and Flare fittings.

All of these fittings have both male and female ends used in propane systems and some styles can be found in more than one size. Being able to identify the fittings and know what types of hoses they are commonly found on will make replacing or adding a component a much easier process.

Type 1/ACME Propane Fitting

A Type 1, also known as an ACME fitting, is the fitting used on modern DOT propane tanks. These fittings are used today because they are less prone to leaks and do not require tools for installation like POL fittings. The Type 1 fitting uses the threads on the outside of the tank valve to connect the pigtail hose to the propane cylinder.

This fitting is used on the tank-side end of RV Pigtail Hoses, which connect the propane tank to the propane regulator.

Typical Applications

DOT Cylinders

POL Propane Fitting

A POL fitting is commonly found on the ASME tank used on motorized RVs to connect the propane tank valve to the RV regulator. Before the introduction of Type 1 fittings, POL fittings were the standard fitting for all propane tanks. Now, both types of fittings are featured on DOT cylinders. The POL fittings are the threads on the inside of the DOT cylinder's connector. Also note that POL fittings feature left-hand threads.

POL fittings are commonly found on the tank ends of POL Pigtail Hoses and Supply Hoses. Pigtail hoses connect the propane tank to the regulator and auxiliary hoses connect an extra propane tank into a propane tee to supplement a camper's propane system.

Typical Applications

ASME and inside threads of DOT Cylinders

Male Disposable Cylinder Port

The Male Disposable Cylinder Port is found on small throwaway propane cylinders. The Disposable Cylinder Port is also called a throwaway fitting, a 1"-20 fitting, or a #600 fitting.

In addition to the throwaway cylinder, typically the male-style fitting is also found on Propane Tees and Adapter Hoses. The adapter hoses are designed as accessory or multi-purpose hoses to connect propane appliances to the propane tank.

Typical Applications

Portable propane accessories, such as grills or fire pits

Female Disposable Cylinder Port

The Female Disposable Cylinder Port is commonly found on propane accessories compatible with throwaway propane tanks. These fittings are also known as throwaway fittings, 1"-20 fittings, or #600 fittings.

This fitting is typically found on Adapter Hoses, much like the male disposable cylinder port fitting. The female side of the fitting is found on the end of the hose that connects to the throwaway propane cylinder.

Typical Applications

Throwaway Propane Cylinders
Propane Tees

Male Inverted Flare

Male Inverted Flares are most commonly used as a connection fitting at a propane regulator. If your propane regulator is fitted with a gold adapter fitting, then the regulator requires a pigtail hose with a Male Inverted Flare fitting.

The most common place to find a male inverted flare fitting is on the regulator side of a Pigtail Hose to connect the propane tank to the regulator.

Typical Applications

Propane Regulator Inlet

Female Inverted Flare

A Female Inverted Flare fitting can commonly be found on the inlet adapters used with two-stage auto-changeover propane regulators. If your propane regulator is fitted with the gold adapter fittings, you will need a pigtail hose with a mating Male Inverted Flare fitting.

Typical Applications

Propane Regulator Hose

Male NPT - 1/4"

1/4" Male Pipe Thread fittings can be found on hose assemblies, extension hoses, and as inlet connection fittings on pigtail hoses.

1/4" MPT fittings are commonly found on Pigtail Hoses, used to connect the regulator to the propane cylinder.

Typical Applications

Propane Regulator Inlet

Male NPT - 3/8"

3/8" Male Pipe Thread fittings can be found on hose assemblies, extension hoses, and as outlet connection fittings on propane regulators.

Propane hoses that commonly feature 3/8 Inch MPT Fittings are a type of hose assembly called trunk hoses. These trunk hoses are used to connect the regulator outlet to the camper's propane piping system. These 3/8 Inch MPT fittings are also common on Extension Hoses, which can be used when a the hose needs to be made longer.

Typical Applications

Propane Regulator Inlet

Female NPT

Female National Pipe Thread fittings can be found on hose assemblies, extension hoses, and as inlet fittings on components, such as propane regulators or quick disconnect fittings. The fittings are either 3/8" or 1/4" fitting sizes.

When found on hoses, Female NPT fittings are typically 1/4 inch in size. These fittings are commonly found on Extension Hoses, to help the propane system have the necessary length to reach from the tank to the propane accessory.

Typical Applications

A Variety of hoses, such as pigtail hoses and extension hoses, as well as Adapter Fittings

Male Quick-Disconnect

Male Quick-Disconnect fittings are commonly found as the inlet fitting on portable grills, quick disconnect adapter hoses, and auxiliary supply hoses. Quick-Disconnect fittings make it easy to connect accessories to your propane supply.

Hoses that feature male quick disconnect fittings are Quick Disconnect Adapter Hoses and Auxiliary Supply Hoses. Quick disconnect adapter hoses make it easy to connect a propane appliance to the female quick disconnect fitting on your camper. One side of these hoses feature a male quick-disconnect fitting while the other side features either a female quick disconnect, a female flare, or a male disposable cylinder port. The auxiliary supply hoses feature the male quick-disconnect fitting on one end with a POL fitting on the other. When used with a propane tee, these auxiliary hoses allow a 20- or 30-pound propane tank to be added to the camper's propane system.

Typical Applications

Propane Tees and Auxiliary Propane Ports on Campers

Propane Tees and Auxiliary Propane Ports on Campers

Female Quick-Disconnect

Female Quick-Disconnect fittings are found on some campers to easily connect propane accessory to propane system. Many times if your camper has an outdoor kitchen, there will be a Female Quick-Disconnect fitting somewhere along the frame under this kitchen area so you can easily connect your small propane grill. This style fitting allows for quick hook up and removal with a single hand. The male fitting simply pushes into the female and the fittings can be separated by pushing back on the black piece on the female end to release the ball bearings holding the male fitting in place.

Hoses that feature female quick-disconnect fittings are Adapter Hoses. These hoses are used to connect propane accessories, such as a grill, to the camper's propane tee. The female quick-disconnect end of the house fits on the accessory's male quick-disconnect fitting while the male end of the hose fits to the propane tee.

Typical Applications

Portable Propane Accessories, such as table-top grills

Flare Fitting

A Flare Fitting is used to connect a hose assembly to the camper's gas piping system. Most will use a 1/2" female flare fitting on the hose to connect to the camper's propane system piping. It is also possible to find 3/8 inch female flare fittings on hoses used to connect a propane supply to an accessory.

Female flare fittings can be found on Hose Assemblies, Extension Hoses, and Adapter Hoses. Flare Fittings in 1/2 Inch size are only found on hose assemblies and are used to connect the propane regulator to the camper's propane piping system. Hoses that feature 3/8 Inch female flare fittings are extension hoses, hose assemblies, and adapter hoses. If the camper's propane piping system features a 3/8 male flare fitting, the hose assembly will need to have a 3/8 female flare fitting. Extension hoses allow you to add additional length of hose to your propane setup. Adapter hoses feature a male quick disconnect fittings on the opposite end and will allow you to connect a propane grill into a female quick disconnect fitting on the camper.

Typical Applications

Male Flare fitting found on camper's distribution manifold with Female fitting found on hose assembly

RV Propane 101: How Does My RV's Propane System Work?

Questions and Comments about this Article

Gah 8/14/2020

If you have a POL soft-nose fitting to the propane tank, should it be full flow or restricted flow? Is there any kind of safety valve in the POL? I've seen some that seem to have a small ball valve that would shut off the flow from the tank if there is an excessive pressure demand (i.e. leak) at the regulator or post regulator. We're talking a small B RV application. 97322

Reply from Jon G. 8/27/2020

You can fully open your propane tanks with a POL fitting installed, you'll just want to do a soapy water test to make sure the connection is secure. We do have some fittings like the MB Sturgis # 204051-MBS with a built-in safety feature to help out in the event of a leak. 72787

Warren J. 6/17/2020

My camper has a quick connect fitting near the outdoor kitchen, but I would like to attach my portable grill (charbroi) that uses the disposable 1 lb bottle. But that means I have a regulator on the bottle to the quick connect. From the quick connect it connects to another regulator (on the grill). Basically, making it so there is not sufficient flow to the grill. Is there a solution other than continue to use bottles? Thanks 81195

Reply from Chris R. 6/22/2020

If you can't remove the regulator from the grill, you'll need to bypass the one coming from your RV's tank with a tee, part # 103613-MBS . Then from the quick disconnect on the tee you can use the propane hose # 100476-120-MBS to go from there to the grill (it sounds like you MIGHT already have this hose). 66874

Jerome 4/19/2020

Should the supply end of a 12 lp hose always have the male npt fitting to allow the full lpg flow from the the regulator to the appliance? 73603

Reply from Chris R. 4/21/2020

The supply end of the hose does always feature an MPT, but it's more because the regulator will always have a FPT fitting to match. It's not really related to flow rate. 60101