Stanley Steam Car Pilot Fuel Strainer

PILOT FUEL STRAINER

the pilot fuel system strainer is located behind the burner access door at the front left side of the car

There are numerous fine passages for the pilot fuel to flow though on its way from the tank to the pilot burner. In order to insure any debris that might get into the pilot fuel tank and eventually into the fuel system strainer is installed in the fuel line. While the strainers don't generally clog up they are not easy to clean as they have to be removed from the piping system to be disassembled and cleaned.

ABOUT STRAINERS AND FILTERS

Strainers and filters are different in that strainers are for retaining larger solid particles of material. Strainers are basically fine wire screens that trap larger particles of matter while allowing a fluid and any matter suspended in the fluid to pass. A filter generally consists of a porous material (like paper) through which a gas or liquid is passed to separate out any matter in suspension. As the gas or liquid passes through the porous material any suspended matter is trapped in the crevices and cavities of the porous material. The basic difference in the Stanley strainer and filter is in the size of the wire screens used with the filters having a much finer screen than the strainer.

The pilot fuel strainer is a two piece brass casting that is screwed together. One half of the casting has an 1/8" male pipe fitting while the other half of the casting has an 1/8" female pipe fitting. Unscrewing the two casting halves exposes the very woven wire cloth screen on the inside of the strainer. Generally a quick cleaning in solvent is all that is required to remove any collected debris and build-up before the strainer can be reassembled and reinstalled.

One of the important properties of the strainer requires it to withstand the pressures that are present in the pilot fuel system (often as high as 40 PSIG) once the pilot tank has been pressurized. The woven wire cloth screen that is used is of brass and generally in the 100 x 100 mesh size (100 x 100 openings per inch) to filter out particles larger than 0.005" At this mesh size only 30 percent of the screen's area is open to allow fuel flow thus the screen area has to be of a large diameter to permit the screen to have the equivalent open area that the 1/8" pipe has supplying the strainer. The woven wire mesh screen is placed over a larger screen (seen as the dark areas in the photo) such that the larger screen provides the structural support for the woven wire cloth.