Camco 59954 Brass Propane Fitting, 1/4 in NPT Check Valve

If you've ever tried to hook a propane pigtail up to a regulator and found the threads just don't match, this little Camco brass fitting is the piece you're missing. It adapts a pigtail that ends in a 1/4 inch inverted flare over to a regulator that has a 1/4 inch female NPT port. One end is 1/4 inch male NPT, the other is a 1/4 inch female inverted flare, and there's a check valve built in so propane only moves one direction through it.

That check valve is the part worth talking about. It only lets gas flow one way, from the pigtail side toward the regulator, so you get a bit of built-in protection against backflow if something downstream isn't sealed the way it should be. It's a small thing, but on an LP system the small things matter. Note that this is not a shut-off valve. There's no lever or knob to close the line here, so you'll still want a proper shut-off at the tank or in the run if your setup calls for one.

The two connection styles trip people up more than anything. NPT is the tapered pipe thread you'll find on a lot of regulator ports. The inverted flare is the seat-style fitting common on propane pigtails and hoses. They don't thread into each other directly, which is exactly why this adapter exists. If your pigtail is inverted flare and your regulator is female NPT, this bridges the two without you having to swap out either part.

A quick word on where this sits in the system. On most setups the pigtail runs from the connection at the cylinder over to the regulator that steps the pressure down for your appliances. That pigtail often ends in a 1/4 inch inverted flare. Your regulator's inlet, depending on the brand and vintage, might be a 1/4 inch female NPT port. When those two don't match, you either track down a different pigtail or you add an adapter like this one. Adding the fitting is usually the faster, cheaper fix, and because it's brass with a check valve you're not giving up anything on safety to get there.

On the install side, treat the NPT end like any gas pipe thread. Use a gas-rated thread sealant on the male NPT threads, snug it down, and check the joint with soapy water once you've got pressure on it. The inverted flare side seats metal to metal, so it doesn't need sealant, just a clean face and enough torque that it doesn't weep. Take your time, watch for bubbles, and don't rush the leak check. Propane isn't something you eyeball. And if you're not fully comfortable working on a gas line, there's no shame in handing it to someone who is.

It's solid brass, which is what you want on anything carrying propane outdoors. Brass shrugs off corrosion far better than plated steel, and it holds up to the temperature swings an RV bay or a grill cabinet throws at it. We see this adapter used on RV LP setups, on portable regulators, and on grill and heater conversions where the pigtail and the regulator came from different parts of the supply chain and just don't speak the same thread language out of the box.

Keep in mind what this is. It's a 1/4 inch adapter fitting with a check valve, nothing more. It doesn't regulate pressure, it doesn't shut the gas off, and it won't fix a pigtail that's cracked or a regulator that's past its service life. What it does do is get an inverted flare pigtail talking to a female NPT regulator port cleanly and safely, and for that one job it's the right brass part to reach for.