A reliable, code-compliant connection between your RV propane cylinder and regulator. The Marshall Excelsior MER401-12 is a 12-inch flexible thermoplastic pigtail hose built with an excess flow safety device, fully crimped brass ferrules, and UL/CGA-listed construction -- exactly what you need for permanent or semi-permanent LP cylinder hookups on RVs, campers, and trailers.
The MER401-12 is designed for RV propane systems where a short, flexible connection is needed between a POL-type cylinder valve and a downstream regulator or appliance fitting. The 12-inch length keeps the hose tight and tidy while still providing enough flex to seat both fittings without stress on the connections.
The integrated excess flow device is a critical safety feature -- it automatically restricts gas flow if the hose is severed or if downstream flow exceeds safe limits, helping to limit gas release in an accident or hose failure. This makes it a preferred choice for many RV technicians and a requirement under some DOT and NFPA 58 installation guidelines.
Automatically limits gas flow if the hose is cut or a downstream failure occurs, a critical safety layer for LP cylinder installations.
Rated for 350 PSIG working pressure with a 400 lb. pull test rating -- well above typical RV cylinder pressures.
Both ends are factory-crimped with brass ferrules for a leak-free, permanent seal that does not loosen over time.
Flexible thermoplastic hose body is UL listed and CGA approved, meeting the safety standards required for LP gas service in recreational vehicles.
The hose assembly includes thermal protection to help resist heat-related degradation near high-temperature environments common in RV propane compartments and exterior mounting areas.
The POL (Prest-O-Lite) 7/8" nut end connects left-hand threaded to a standard DOT propane cylinder valve. The 1/4" male inverted flare end connects to a regulator or appliance inlet that accepts a 1/4" inverted flare fitting (also noted as 1/4" SAE flare in some regulator specs). Verify both your cylinder valve type and your regulator inlet before ordering. POL fittings do not use thread sealant -- they seal via metal-to-metal contact.