WATER GLASSES: KLINGER 8 5/8-INCH REFLEX GLASS

A fact about liquids is that any liquid will constantly seek its own level. The water glass operates based on this basic principle. The water glass communicates with a boiler at two locations. One location is at or near the top of the boiler. The second location is typically lower than the firebox crown sheet. When a fire tube boiler is operating normally, This allows the steam from the boiler to enter the glass at the top and water to enter at the lower connection. The bottom of a water glass is to be set at a height of at least three inches above the highest point on the crown sheet (See 49 CFR part 230.51 Number and Location under Water Glasses and Gauge Cocks).

Each water glass can be isolated from the boiler by closing the two shut off valves. In addition each water glass is required to be equipped with a drain valve to drain the water glass (See 49 CFR 230.52 Water Glass Valves). To see the information on the brass plate on the water glass see the next photo.

Checking for proper Operation of the water glass

To check a water glass for proper operation first observe where the water level is in the glass before starting the test.

Crack open the drain valve. This should be open a small amount to avoid diging up ballast and throwing it at people. Notice the water drain from the water glass and the associated noise. The noise is a rumble type sound.

Then close either the top or bottom valve. The glass should then show the fluid for the valve that remains open.

Then close the other valve and the water glass should both drain completely and the glass should be isolated from the boiler. Incase the glass breaks or a repair needs to be made you need to be able to isolate the water glass. By performing this test daily you are monitoring the ability of the valves to isolate the water glass.

Then fully open the first valve you closed. You should see the water glass fill with either steam or water depending on which valve you open first.

Now open the other shut off valve.

Close the drain valve.

Finally observe that the water returned to the same level. If the water level did not return to the same level, something is wrong.

This proceedure is a basic daily inspection of a water glass. It will not tell you if the boiler is foaming or experiencing other issues.

The hand stamped metal tag in the photo states;

“Insure Safety On Max Grades Water Must Fall Below This Level.”

When a water glass is operating properly, the water in a water glass is inflenced by the vibration of the operation of the locomotive. When a steam locomotive is in motion the water level can change up to an inch or more over track where the grade and curvature are consistant. Because of this bobbing of the water level, the water level that one would estimate is an average of the bobbing interface between the water and steam.

Water Glass Brass Tags used on the southern pacific

Prior to the current Federal Code of Regulations requiring two water glasses, stem locomotives were only required to be equpped with one wter glass in the United States. The Southern Pacific equipped their locomotives including 3420 with two water glasses.

Steam locomotives were assigned to a division or portion of the railroad. Each division would have a timetable indicating any operating restrictions for each class of locomotives. The territory would also have certain caracteristics including ruling grades. To assist crews with maintaining the minimum level of water to safely operate over the railroad the Southern Pacific installed the brass tag seen in the adjacent photo. 3420 was assigned to operate on the Rio Grande Division. The Rio Grande Division was known for relatively flat territory resulting in the closest placement of the tags to the top of the crown sheet on the Southern Pacific.