New York Codes, Rules and Regulations
Title 17 - DEPARTMENT OF TRANSPORTATION
Chapter VI - Transportation Regulations
Subchapter F - Railroad And Street Railroad Corporations
Article 2 - Safety
Part 922 - Locomotive Boilers And Steam Reservoirs
Section 922.13 - Water glass and gauge cocks

(a) Number and location. Every boiler shall be equipped with at least one water glass and three gauge cocks. The lowest gauge cock and the lowest reading of the water glass shall be not less than three inches above the highest part of the crown sheet. The location of the water glass on the back head of the boiler shall be such that it may be clearly seen by the engineman and fireman when in their natural positions in the cab.

(b) Water glass valves. All water glasses shall be supplied with two valves or shut-off cocks, one at the upper and one at the lower connection to the boiler, and also a drain cock, so constructed and located that they can be easily opened and closed by hand.

(c) Time of cleaning. The spindles of all gauge cocks and water glass cocks shall be removed and cocks thoroughly cleaned of scale and sediment at least once each month. When gauge cocks having offset extensions or elbows protruding into the water space are used, the body of the gauge cock shall be removed from the boiler at the time of cleaning, and the opening through the body thoroughly cleaned.

(d) All water glasses must be blown out and gauge cocks tested before each trip, and gauge cocks must be maintained in such condition that they can be easily opened and closed by hand without the aid of a wrench or other tool.

(e) Water and lubricator glass shields. All tubular water glasses and lubricator glasses must be equipped with a safe and suitable shield which will prevent the glass from flying in case of breakage, and such shield shall be properly maintained.

(f) Water glass lamps. All water glasses must be supplied with a suitable lamp properly located to enable the engineman and fireman easily to see the water in the glass.