The small fitting on the regulator end of an RV propane pigtail determines which inlet it can connect to. Marshall Excelsior's MER425 and MER426 hoses share a Type I cylinder connection, but they finish differently. Use these diagrams, model numbers and product photographs to identify the right connection style before selecting a hose.
Two hose ends that are not interchangeable
On the cylinder side, these models have a female QCC/Type I connection. Look at the other end of the hose to determine whether it has an inverted-flare connector or male pipe threads.
MER425 and MER425H
MER426 and MER426H
What the exact hose numbers tell you
| MPN | Regulator-side connection | Identifying feature |
|---|---|---|
| MER425-15 | 1/4-in male inverted flare | 15-in standard Type I/QCC propane pigtail |
| MER426-15 | 1/4-in male NPT | 15-in standard Type I/QCC pigtail with pipe-thread end |
| MER425H-15 | 1/4-in male inverted flare | 15-in 400,000-BTU/hr high-flow Type I hose |
| MER426H-15 | 1/4-in male NPT | 15-in 400,000-BTU/hr high-flow Type I hose, pipe-thread outlet |
| MER425-15P2 | 1/4-in male inverted flare | Two packaged standard 15-in pigtails |
| MER425H-15P | 1/4-in male inverted flare | Single packaged high-flow 15-in pigtail |
The full model number matters. On these manufacturer parts, the H identifies high flow, while P identifies a packaged hose and P2 a two-hose package. A similar-looking package should not be treated as interchangeable without confirming its markings.
Standard Type I versus high-flow Type I pigtails
Marshall Excelsior identifies the standard RV Type I pigtail with a green cylinder nut and a 200,000-BTU/hr flow rating. Its high-flow range has a red Type I nut and is rated for up to 400,000 BTU/hr. The high-flow series also incorporates excess-flow and thermal-link features.
The regulator still has its own limits. Under the manufacturer's specified test conditions, the MEGR-253 standard auto-changeover regulator provides 225,000 BTU/hr from the primary side and 150,000 BTU/hr from reserve; the MEGR-253H high-capacity model is rated at 350,000 and 200,000 BTU/hr. Select components for the complete gas system rather than judging capacity by hose appearance alone.
Compare product photos and exact part numbers
These items are catalogued at NewRVParts. The photos link directly to the corresponding listings, where current availability and complete product information can be checked.
Manufacturer fitting specifications
Compare the manufacturer records for MER425-15, MER426-15, MER425H-15, MER426H-15 and the MEGR-253 regulator. Use the relevant factory installation instructions for service or modification work.