hi ron,

stick with the LBSC and Don Young type as per your drawings.

schraeder tyre valves are ok for salvaging for the stainless springs for whistle valves etc. they are pretty much useless if used as a unit on miniature locos. ignore what your club members say! (i tried them as boiler check valves on one loco but they quickly got replaced).

when you make check valves for lubricators, test them before fitting on an air line so that you are sure they dont leak. i make my lubricator check valve springs out of phos bronze wire and set them to be just above working pressure of the boiler so as not to strain the lubricator, testing them with a gauge on air. however, all my current locos have sight feed hydrostatic displacement lubricators fitted, which Don Young advocated, and with which i heartily agree. i also make these myself as unfortunately some of the commercial fittings are not well made and not up to the job. not that i would pay for these things anyway as i prefer to make them myself!

cheers,

julian