Wheel Valve. A stop or grate valve opened by means of a hand wheel and screw, as distinguished from those patterns of gate valves in which the valves are opened or closed quickly by means of levers, or the many types of butterfly and other throttle valves.

Whitworth Thread. The standard thread for screws, employed in England and her colonies, and on the European Continent. The angle of the thread is 55°, one-sixth being rounded off at top and bottom.

Widemouth Socket.-A well borer's fishing tool, in which the socket is fitted with a bell mouth, nearly the full bore of the casing, thus making it easy to grip the ends of broken poles or the like, when lost at the bottom of a well.

Wine Bore.-A term used to indicate standard pipe thread (rare and poor usage).

Wiped Joint.-A lead joint in which the molten solder is poured upon the desired place, after scraping the fitting parts together, and the joint is wiped up by hand with a moleskin or cloth pad while the metal is in plastic condition; it makes a neat and reliable connection in the pipe.

Working Barrel.-The body of pump used in oil wells. Wye; Y.-A fitting either cast or wrought that has one side outlet at any angle other than 90°. Usually set 45°, and always so set unless angle is specified. It is usually indicated by letter "Y."

Y; Wye.-Which See.

Y.

Y Base. The same as a crotch or back outlet return bend, except that the horns are parallel.

Y Bend.-Y; Wye.

Y Branch.-A Wye. Sometimes used to designate a fitting whose shape is nearly like that of a single sweep tee.

Yoke. In a rising stem valve, the portion of the bonnet that supports the nut, hand wheel, etc. A pipe with two branches; as, for hot and cold water, uniting them to form one stream.

HAZARDS IN HANDLING GASOLINE.

The following are extracts from a paper recently issued by the Department of the Interior, Bureau of Mines, dealing with the hazards attendant on the handling of certain petroleum products, particularly naphtha and gasoline:

Many fires originate from the cleaning of silks with gasoline, the violent rubbing of the silk generating static electricity, which produces a spark that ignites the vapor.

Many jobbing tailors cause fires by using gasoline in an open vessel and smoking a cigarette or cigar at the same time.

A dangerous practice, common in many garages, is the cleaning of automobile parts with gasoline from an open can. Employees find it easy to clean grease and oil from the motor and other parts with gasoline from an open can using a brush saturated with gasoline, and the gasoline is readily ignited by a spark. Such a spark may be caused by striking two pieces of metal together, by the ignition system on the automobile when the starting crank is turned, and in other ways. In one instance, a nut that stuck was struck with a wrench, causing a spark. The car was instantly enveloped in flame.

Detailed Precautions Concerning the Handling of Gasoline. In establishments where benzine, gasoline, naphtha and other liquids are used, care should be taken to see that the smallest practicable quantities are used, and that the liquids are handled in an approved manner.

No open light or flame of any kind, nor any machine or belt capable of producing a spark, should be allowed in the room where the gasoline is being used. All shafting and machines with belt that are liable to cause a static electric spark should be well grounded.

Only incandescent electric lights should be used, and these should be provided with guards to prevent their being smashed. All electric switches, fuses, etc., should be outside the room.

Danger signs should be posted on all doors opening into the room, warning against the carrying of open lights of any kind inside.

When large quantities of the inflammable liquids mentioned are used, the main supply should be stored in a metal tank, buried under ground and a safe distance from buildings. The working supply should be pumped into the buildings as needed and the system so arranged that when the pump is stopped all liquid in the pipes will flow back into the supply tank. When it is not possible to use a pump and a buried tank, the main supply should be stored outside and well away from other buildings, under lock and key. Only small quantities of working supplies should be taken into the building, closed metal cans, preferably safety cans, being used as containers.

When the use of an open pan is necessary, the opening should be as small as possible and a cover should be provided. The cover should be put on whenever the pan is not in use.

Signs should be posted prohibiting an open flame near the place of storage or near a pump or other handling apparatus. The signs should explain the danger involved and give instruction for safe methods of operation.

Empty gasoline barrels should be stored with bungholes down, in safe places in the open air.

Rooms in which explosives or dangerous gases or vapors are used or generated should be safely inclosed, and should be provided with an improved system of ventilation.

Gasoline vapor is heavier than air, and a suction fan should be used to insure proper ventilation.

Joints in tanks, pipes, conveyers, etc., used for storage of explosives, liquids, gases or vapors should be kept tight.

Before work is done on vessels, pipes, conveyers, etc., used for storage of explosives, sufficient time should be given to allow gas to escape.

Special care should be exercised before work requiring the use of heat or flame is done. Apparatus that has contained explosive gas should be filled with water or steam to force out the gas.

Don't spill gasoline.

Don't fill the tank of the liquid-fuel stove full (the contents may expand). Don't use a liquid-fuel stove that leaks.

Don't use a gasoline stove in a closed room. Have plenty of ventilation to carry the vapor out of the room.

The following somewhat technical explanation of gasoline explosions, quoted from this government report, is worthy of careful reading:

At ordinary temperatures air will hold about 5 to 28 per cent of gasoline vapor. As gasoline is about three times as heavy as air, in a room containing mixture of the vapor with air, the vapor is found in largest proportions near the floor.

The limits of explosibility of mixtures of gasoline vapor and air are between about 1.4 and 6 per cent of gasoline vapor, although dangerous flashes may be produced with mixtures containing less and more than these proportions. In other words there is needed only a small proportion of gasoline vapor to render air explosive-1.4 cubic feet of the vapor to 97.5 cubic feet of air. One gallon of gasoline can, under ideal conditions, render 2100 cubic feet of air explosive.

A dangerous feature of gasoline vapor is that it may travel a considerable distance from the gasoline and there be ignited, the flash traveling back to the container of the liquid and causing a roaring fire in a few seconds.