Home > LP Gas > LP Hoses >

Marshall Excelsior MER401-30 LP Pigtail Hose 30 in. Excess Flow POL 7/8" Nut x 1/4" Male Inverted Flare

Marshall Excelsior MER401-30 30-inch LP pigtail hose with excess flow POL 7/8-inch nut and 1/4-inch male inverted flare fitting, flexible thermoplastic construction

30" Pigtail Hose - Excess Flow POL (Prest-O-Lite) 7/8" Nut x 1/4" M. Inverted Flare

List Price: $21.89

: $15.99

You save $5.90!

Part Number: MER401-30
Manufacturer: Marshall Excelsior

Quantity in Stock :36

Availability: In Stock

Qty:

Marshall Excelsior 350 PSIG Rated UL / CGA Approved MER401-30 -- 30" LP Pigtail Hose with Excess Flow Protection

A purpose-built propane pigtail for RV regulator connections. The Marshall Excelsior MER401-30 connects your LP tank valve (POL fitting) directly to a regulator or appliance inlet with a built-in excess flow feature that limits gas flow in the event of a line rupture -- a critical safety layer for any LP installation on an RV, camper, or trailer.

Reliable LP Pigtail Built for RV Propane Systems

The MER401-30 is a 30-inch flexible thermoplastic LP hose designed for use between an LP cylinder and a two-stage or single-stage regulator. One end terminates in a POL (Prest-O-Lite) 7/8-inch left-hand nut that threads directly onto a standard DOT propane cylinder valve. The other end is a 1/4-inch male inverted flare fitting that connects to regulator inlets and most standard LP supply line fittings.

Both ends feature fully crimped brass ferrules for a leak-free, pull-resistant connection. The hose jacket is flexible thermoplastic rated for outdoor LP service and includes thermal protection. Marshall Excelsior manufactures this hose in the USA and backs it with a limited 5-year warranty.

Excess Flow Safety

Integrated excess flow device limits gas flow automatically if downstream pressure drops unexpectedly due to a line break or disconnect.

Crimped Brass Ferrules

Both ends fully crimped -- no clamps to tighten or re-check. Factory-crimped brass provides a permanent, secure seal on flexible thermoplastic hose.

UL and CGA Listed

Approved to Underwriters Laboratories and Compressed Gas Association standards. Meets requirements for LP hose assemblies used in RV and recreational applications.

Made in USA

Manufactured by Marshall Excelsior Company, a Michigan-based LP equipment specialist with decades of gas system component production.

Fitting Identification and Thread Details

Getting the fittings right is essential with any LP hose. Here is what each end of the MER401-30 looks like:

POL End (tank side): 7/8-inch left-hand internal thread nut. This is the standard POL or "Prest-O-Lite" connection used on most US DOT propane cylinders. It threads onto the cylinder valve outlet counter-clockwise (left-hand thread -- no wrench flats on the cylinder valve, tighten by hand until snug, then a quarter turn with a wrench).
Inverted Flare End (regulator side): 1/4-inch male inverted flare (MIF). This mates to a 1/4-inch female inverted flare (FIF) inlet, which is the standard inlet on most Marshall Excelsior, Cavagna, and OEM RV regulators. It is NOT a standard NPT thread.

Excess Flow Explained: The built-in excess flow device is calibrated to allow normal LP appliance draw. If flow suddenly exceeds the rated threshold -- such as when a hose is severed or a fitting is pulled loose -- the valve restricts gas flow to a trickle. To reset, close the cylinder valve completely, wait 30 seconds, then slowly reopen it.

Common RV Applications

This pigtail is used wherever a flexible connection is needed between a horizontal or vertical DOT cylinder and a regulator. Typical installations include:

Single-cylinder RV propane systems with a simple on/off regulator
Dual-cylinder systems as the hose connecting each cylinder to the automatic changeover regulator
Travel trailer tongue-mounted propane compartments
Fifth wheel and motorhome LP cylinder bays where the regulator mounts to a bracket separate from the cylinder
Portable generator propane connections using a POL-to-inverted-flare adapter

Length Note: 30 inches is the most common pigtail length for RV dual-cylinder setups where the changeover regulator mounts on a center rail between two 20-lb or 30-lb cylinders. If your cylinder bay has a longer span or a low-mounted regulator, Marshall Excelsior also makes this hose in other lengths (12-inch, 15-inch, 24-inch variants in the MER401 series).

Installation Tips

Best Practices for a Leak-Free Connection:

Always use an LP-rated thread sealant or PTFE tape rated for gas service on the inverted flare male threads if required by your regulator instructions -- many inverted flare fittings seal on the flare seat and do not require tape.
Hand-tighten the POL nut onto the cylinder valve first, then snug with a wrench. Do not overtighten -- POL connections use a nylon or brass seat, not a thread seal.
After connection, perform a leak test with a LP-rated leak detection solution. Never use an open flame to check for leaks.
Route the hose to avoid sharp bends, abrasion against metal edges, and contact with hot surfaces or exhaust.
Inspect hose and ferrules annually for cracking, brittleness, or corrosion. Replace immediately if any damage is found.

Do Not Exceed Service Life: Even if the hose shows no visible damage, LP hoses should be replaced every 5 years or at the manufacturer warranty interval, whichever comes first. Thermoplastic hose degrades from UV exposure, ozone, and LP condensate over time.

Product Specifications

Manufacturer	Marshall Excelsior Company
Part Number	MER401-30 / 06-0267
UPC	815505010146
Country of Origin	USA
Warranty	Limited 5-year manufacturer warranty

Hose Dimensions

Hose Length	30 inches
Hose Inner Diameter	1/4 inch
Hose Construction	Flexible thermoplastic with thermal protection jacket
Ferrule Material	Brass, fully crimped both ends

Pressure and Safety Ratings

Working Pressure	350 PSIG maximum
Pull Test Rating	400 lbs.
Hose Listing	UL Listed, CGA Approved
Excess Flow Device	Included, integrated at POL end

Fitting Details

Tank-Side Fitting	POL (Prest-O-Lite) 7/8" left-hand nut
Regulator-Side Fitting	1/4" male inverted flare (MIF)
Thread Hand (POL)	Left-hand (standard for LP cylinders)
Compatible Cylinder Valves	Standard US DOT propane cylinder valves with POL outlet

What Is Included

In the Box	1x MER401-30 pigtail hose assembly
Not Included	Regulator, cylinder valve, adapters, thread sealant

Important Safety Information

This hose is rated for LP (propane) gas service only. Do not use with natural gas, compressed air, or oxygen systems.
Maximum working pressure is 350 PSIG. Do not use in high-pressure service exceeding this rating.
POL fittings are left-hand thread. Forcing a right-hand thread connection will damage the valve seat and cause leaks.
Always perform a leak test with approved LP leak detector solution after installation. Never test with a flame.
If excess flow device trips during normal use, check all downstream connections for leaks before resetting.
Replace hose at or before the 5-year service life regardless of apparent condition.
Do not use as a permanent rigid connection -- this is a flexible pigtail designed to accommodate minor movement and vibration only.
Installation must comply with NFPA 58 (Liquefied Petroleum Gas Code) and all applicable local codes.

Browse for more RV Accessories in the same category as this item:

LP Gas > LP Hoses
LP Gas


Lippert 2022013916 All Purpose Cleaner 32 oz -- Dye-Free Interior RV Cleaning Spray	Curt 52044 Push-to-Test Trailer Breakaway Kit with Top-Load Battery Case	InfiniteRule 61675-S 3-Pack Hitch Lock Set for B&W Tow & Stow 10K/18K Hitches	Ventline BVC0573-31R Roof Vent Screen Frame with Rocker Switch and Wire, Birch White
$9.02	$58.49	$112.49	$31.99