Many RV propane regulator fittings have nearly identical brass hex bodies. Before choosing a replacement, distinguish a 1/4-inch inverted-flare connection from a 1/4-inch pipe-thread connection and confirm whether the fitting also contains a check valve. This illustrated guide compares JR Products, Marshall Excelsior and MB Sturgis part numbers used around propane regulators and cylinder manifolds.
Inverted flare and pipe threads are different sealing connections
These examples illustrate the role of a female inverted-flare-to-male-thread adapter. The nominal 1/4-inch size does not make the two threads or sealing faces interchangeable.
Straight adapter example
Check-valve version
What needs checking beyond the two ends?
Some dual-cylinder regulators and manifolds require a check feature to prevent unintended gas flow between supply connections. A check valve's presence, rated flow and installation direction must be established from the actual manufacturer model—not inferred from a similar brass fitting. The separate Marshall Excelsior ME1700A carries a manufacturer-described dual-cylinder equalization/check function and must be matched to its specific application.
For MB Sturgis 402258MBS, the manufacturer's description identifies a female inverted-flare end and a male-thread regulator side, but the available catalog record does not fully resolve the male thread designation. Do not select it simply because it visually resembles 402142PKG or ME2132.
Likewise, a POL connector such as Marshall Excelsior ME353 is a cylinder-side fitting with a 3/8-inch male inverted-flare outlet, not a 1/4-inch female-flare regulator adapter. Flare style, gender, size, pipe-thread designation and the need for a check valve must each be verified.
Exact manufacturer part-number comparison
| MPN | Listed ends | View |
|---|---|---|
| 07-30035 | 1/4-in female inverted flare × 1/4-in male pipe threads | See product |
| 07-30045 | 1/4-in female inverted flare × 1/4-in male pipe threads | See product |
| ME2132 | 1/4-in female inverted flare × 1/4-in male pipe threads | See product |
| ME2132P | 1/4-in female inverted flare × 1/4-in male pipe threads | See product |
| 402142PKG | 1/4-in female inverted flare × 1/4-in male threads | See product |
| 402258MBS | 1/4-in female inverted flare × male threaded end | See product |
| ME1700A | 1/4-in female inverted flare × 1/4-in male threads | See product |
| ME353 | Male POL × 3/8-in male inverted flare | See product |
Part-number suffixes can identify a packaged product, but should not be used to assume identical included components or approval details. Check the original regulator and manufacturer's fitting instructions before making changes.
Compare the actual product photographs
The product cards below link to existing UsedRVParts listings and show the respective catalog images. Each product may be new or used, so check its individual condition and availability. Viewing or pickup, where available, is by appointment in Kelowna.
Manufacturer parts reference
JR Products' LP gas fittings listings distinguish its fitting and check-valve variants. Marshall Excelsior and MB Sturgis publish model-specific propane adapter information and regulator instructions. This page is an identification aid, not gas-piping installation instructions; use a qualified propane technician for component replacement and testing.