Marshall Excelsior Co. Adapters

Marshall Excelsior Co. Propane Adapter Fittings

When it comes to making safe, leak-free connections in LPG and propane systems, few names carry as much weight as Marshall Excelsior Company (MEC). Founded in 1976 and headquartered in Marshall, Michigan, MEC has spent decades engineering precision gas control components trusted by bulk plant operators, RV enthusiasts, and domestic propane users alike. Their adapter fittings sit at the core of that mission — purpose-built hardware that bridges different connection standards without compromising safety or flow efficiency.

Why MEC Adapters Stand Out

Marshall Excelsior adapters are manufactured under rigorous quality standards, and the results show in the certifications they carry. MEC adapter fittings are ISO 9001 certified and approved by both Underwriters Laboratories (UL) and the Canadian Gas Association (CGA) — a combination that reflects genuine third-party validation of safety and performance, not just marketing language.

Construction material matters enormously in gas-handling hardware. MEC adapters are machined from high-quality brass, delivering the corrosion resistance and pressure integrity required in demanding LPG and NH3 environments. Each fitting is also backed by a limited 5-year warranty and proudly carries a Made in the USA designation.

A Wide Range of Connection Solutions

One of the defining strengths of MEC's adapter lineup is the breadth of connection types covered. Whether you need to bridge a Male POL (Prest-O-Lite) fitting to a 3/8-inch Male Flare (as in the widely used ME353), convert a CGA 510 POL cylinder valve to a Type I QCC appliance swivel nut (ME398P), or adapt a camping appliance regulator inlet to a larger bulk cylinder via a 1/4-inch FNPT to 1-inch-20 MNPT configuration (ME492P), there is an MEC adapter engineered for the task.

MEC has also developed adapters specifically designed for quick conversion from Type I (QCC) to different fill applications — a practical solution for propane retailers who fill both 40-pound-or-less DOT cylinders and larger bulk tanks through a single line. These QCC quick-fill adapters (such as the ME393, ME394, and ME569 series) simply hand-tighten onto a compatible filler coupling, making cylinder-type transitions fast and reliable in high-volume dispensing environments.

From the Bulk Plant to the Campsite

What makes MEC adapter fittings particularly versatile is their applicability across multiple market segments. A single product line supports connections in bulk plant, transport, delivery and dispensing, domestic, and recreational settings. For RV owners and campers, MEC adapters provide the critical link between portable appliances and larger propane supplies — eliminating reliance on small disposable cylinders and enabling a more efficient, cost-effective fuel setup on the road or at the campsite.

Explore the full Adapters category to find the right MEC fitting for your propane system, or visit the Marshall Excelsior brand page to browse their complete lineup of LPG regulators, hoses, valves, and fittings.