GLOSSARY OF PUMP AND HYDRAULIC TERMS.
Air-bound. This word applies to both pump and piping and expresses the confinement of air between the discharge valve of the pump and the check-valve or the point of delivery.
Air-cock. Is the same as a pet-cock and is used to relieve pipes that are air-bound.
Air Cock.
Annular Valve. From annular—a ring—i.e., a round valve with a hole in the middle.
Area. The extent of surface, as the area of a piston.
Assembling. Putting together the parts of a machine.
Atmospheric Pressure. The pressure of atmospheric air, not only downward but in every direction, this amounts to about 14.7 lbs. per square inch at the sea level. Usually taken at 15 lbs. to facilitate calculations.
Auxiliary. Something to “help out,” as an auxiliary cylinder or an auxiliary piston.
Ball Check-valve. One in which a metal ball is used in place of a poppet-valve.
Ball Check-Valve.
Balanced Valve. A valve having an equal pressure on all sides. [See equilibrium valve.]
Basket. The outer casing or netting of a foot valve which forms a strainer on a pump suction pipe.
Bends. In pipe, the turns in lines of pipe may be angle bends (called “elbows“) or offset bends.
Bibb-cock. This is a plug cock having an elbow or curved outlet directing the outflow downward.
Bibb-Cock.
Bibb Compression.
Bibb Compression. A bibb-cock having in place of the plug a stem with thread and handle to open by unscrewing; the valve contains fibrous packing and is made tight by compression.
Bonnets. These are covers for the opening into valve chambers of pumps.
Boss. Any round protuberance on a casting to support a stud or to strengthen a steam chest cover, etc.
Bushing. A nut used in pipe fitting, threaded inside and outside to accommodate two sizes of pipe.
Bushing.
Check Valve. A valve through which fluid can pass only in one direction; used between pump and reservoir or boiler. See [swing-check].
Check-Nut. A second nut screwed against the first to hold it firmly in place; also called a lock-nut.
Circulating Pump. A pump arranged to force water through the tubes of a surface condenser. Frequently a centrifugal pump is used as a circulating pump.
Clack Valve. This takes its name from the noise it makes in seating; it is made of leather with a metal weight on top, the leather forming a hinge on one side. In the cut the lifted valve is the “clack.”
Clack Valve.
Clearance. The space or distance by which one piece clears another. The space between piston and cylinder head.
Cock. A faucet or device for opening or closing a passage. The illustration shows a straight-way cock.
Plain Cock.
Column Pipe. A column may be considered as a beam set on end and a column pipe may, similarly, be defined as a pipe set on end. The pipes leading from a water column to boiler.
Compression Gauge Cock. A device having a threaded steam spindle and made tight by compression. The figure exhibits an outside view of a locomotive compression gauge cock.
Compression Gauge Cock.
Corrosion. Rusting or wasting away of the surfaces of metals.
Crow. A claw with a screw attached to support and feed a drill brace for drilling holes in pipes.
Cup Leather Packing. The leather packing used around the ram of a press. In section it resembles a cup—hence the name.
Cup Leather Packing.
Cushioning. This term applied to the operation of pumps, etc., is the imprisoning of steam, water or air between the piston and cylinder head to prevent the piston from impact with the head.
Cylinder Head or Cylinder Cover. A plate which encloses or covers the end of a cylinder.
Dead end of a pipe. The closed end of a pipe or system of pipes.
Disk or Disc. A cylinder, whose length is very short in proportion to its diameter; a round plate with a hole in its center.
Double-eye or Knuckle Joint. A joint formed of two forks or jaws with a cube of iron between them, with a bolt or pin through each jaw and the cube at right angles. Will work freely in all positions from a straight line up to 45°.
Double seated poppet valve. A poppet valve having two valves on one stem, with two seats in the same shell.
Double-Seated Poppet Valve.
Drafting water. Another term for “raising“ water by suction, in distinction to “forcing water.”
Drip-pipe. A device used to draw off the water of condensation from systems of piping, steam cylinders, heaters, etc. Drain-cocks are used for similar purposes.
“Dutchman.” A piece “fitted in” to restore a worn part or to hide a defect.
Duct. A passage or conduit.
“Duty” of pumps. This indicates the measurement of the work performed by pumps. “Duty trials” are careful tests of the work done by the larger pumping-engines.
Elbow. This fitting is used for uniting two pipes together at right angles. The illustration shows a malleable-iron gas-pipe elbow.
Elbow.
Equilibrium Valve. A valve balanced by an equal pressure on both ends.
Expansion Joint. A telescopic slip joint having a packed stuffing box, permitting the parts it connects to expand and contract under variations of temperature.
Expansion Joint.
Face. The broadest flat surface of a piece of work, or the one having the greatest area.
Factor of Safety. When a calculation of the ultimate strength of a machine is to be made it is necessary to provide for contingencies—this takes the form of a multiplier, and is called the factor of safety, or the margin of safety.
Feather, or sunk key. A key that is fast in one piece of work, and an easy fit in the other, as a feather in a shaft.
Flow. Motion of a fluid or liquid in one direction. “Flow-gate“ is a term sometimes applied to a riser.
Flume. An open trough for conveying water.
Gate Valve.
Globe Valve.
Gate Valve. A valve which opens the full area of the pipe, on the principle of a gate in a water flume.
Globe Valve. A valve having a round ball-like shell as shown in the engraving.
Gland. The sliding bushing for holding packing into a stuffing box, adjusted by studs and nuts.
Goose neck. A pipe fitting having two bends in opposite directions which resemble the neck of a goose.
Gridiron Valve. A type of slide valve familiarly called a “grid,” which may be circular or rectangular, consisting of alternate bars and spaces, sliding over a similarly formed seat, the object being to obtain the necessary steam way with a diminished amount of valve travel.
Hand-Nut. A nut having wings or projections so that it may be screwed up by hand without the aid of a wrench.
Hand-Nut.
Head of water. In hydraulics “head“ means pressure due to height of column of water.
Heat Units. The unit of heat is the amount of heat required to raise one pound of water one degree, usually from 32° to 33° Fahr.
“Hesitates.” A pump is said to “hesitate” when the motion becomes uncertain.
Horse-power of a pump. Is the same as is used to designate that of a steam engine, with this exception: the initial pressure in the pump remains constant throughout the stroke. Formula is the same as for a steam engine.
“Hump.” This is an arch or bend which causes an “air pocket” in a water-pipe line.
Hydrant. A valve and spout connecting with a street main.
Hydraulic Belt. An endless woolen band for raising water. The lower bight is immersed in water, and the upper bight passes over a roller. The belt travels about 1,000 feet per minute, and discharges at its upper turn.
Hydraulic Jack.
Hydraulic Jack. A lifting device in which a ram, a pump, and liquid is used instead of a screw.
Hydraulic Pivot. A “slippery liquid support” for an upright shaft, a film of water being introduced beneath it by pressure to support the weight thereof and prevent the usual friction of the shaft on its step.
Hydraulic Shears. A machine for shearing or cutting metals, etc., by the force of water pressure operating cutters.
Hydraulic Valve. A valve for regulating the distribution of water in the cylinders of hydraulic elevators, cranes and other water pressure machines and devices.
Hydraulic Wheel. One for raising water by applied power, as the Noria Scoop wheel, tympanum, etc. See [illustrations] in section relating to the history of the pump.
Impact. The single instantaneous shock of a body in motion when it strikes against another body either in motion or at rest.
Leakage. The loss of water from any cause.
“Lift and drop of a valve.” This term indicates the amount of “play” up and down, designed to be given to a valve by its designer.
Liner. A piece of iron or other metal put behind or on a piece to take up its wear.
Mississippi River
Gauge Cock.
Lost Motion. Motion that is not transmitted on account of the looseness of the parts, hence it is lost.
“Losing water.” A term used when the pump stops, caused by air leaking into the suction pipe, or foreign matter clogging the strainer at the end of the suction pipe.
Low pressure steam. Steam which is either below 30 lbs., or but a few pounds in excess of the atmospheric pressure.
Lug. That which projects like an ear, especially that by which anything is supported, or against which anything bears, or through which a belt passes.
Main. A principal pipe or duct as distinguished from lesser ones, especially a principal pipe leading to or from a reservoir or a fire-main; a “forcing main” is the delivery pipe of a pump.
Mean gradient. The grade of a pipe-line which should be made as nearly straight as possible to avoid air pockets.
Miner’s Inch. The amount of water that will flow per minute through an opening one inch square in a plank two inches thick, under a head of four inches of water above the upper edge of the opening, and is equal to nine United States gallons.
Mississippi River gauge cock. A cock without a handle or thread upon the stem and designed to be opened by pressure upon the top end of the stem as shown.
“Modulus” of a steam pump. The measure or multiplier of power used in operating pumps. Modulus has nearly the same meaning as measure.
Nipple. A short connecting piece of pipe threaded upon both ends.
Outboard delivery pipe. The pipe which leads, in steam vessels, from the condenser through the side of the ship.
Nipple.
Pipette. A small tube used to withdraw and transfer fluids or gases from one vessel to another. The shape differs with the special use to which it is adapted: some are graduated to measure fluids accurately as well as to transfer them.
Penstock. The barrel of a pump in which the piston plays and through which the water presses up; also the conduit or trough from the source of supply to a water wheel.
Pet-cock. This is an air-cock. See [air-cock.]
Pitcher Pump.
Plumb Bob.
Pipe-clamp. A device for connecting one pipe to another without cutting the pipe and inserting a tee; a pipe-saddle performs the same office as the above, but for larger pipes.
Pitcher Pump. A hand pump which takes its name from the shape of its discharge.
Plug-valve. This is a tapering plug which turns in a shell, example, the plug of a faucet. See [Cock.] A fire-plug is a street hydrant to which a hose may be attached.
Plumb-bob. This is a device for testing whether anything stands exactly vertical; a plumb-rule contains a plumb-bob.
Pressure-reducing Valve. A valve for reducing high boiler pressure to low pressure, for steam heating, etc.
Priming. To fill a pump with water when it refuses to lift of its own action, is called “priming the pump.”
Pump-brake. The handle or lever by which a pump is worked.
Pump-box. A cap or case covering the top of a pump; the casings of the upper and lower valves are the upper and lower pump boxes.
Pressure Reducing Valve.
Section.
Pump-chain. An endless chain with discs forming valves at proper distances, working on two wheels, one above and one below, and passing down outside and returning upward through a wooden tube like a belt.
Pump-cheeks. A forked piece serving as a fulcrum for the handle of a pump.
Pump-well. A compartment extending from a ship’s bottom to the lower or the upper deck, as the case may be, to contain the pump stocks, etc. The bilge water collects in the limbers and is discharged through a spout called the pump-dale.
Rain-gauge. A vessel graduated to measure the fall of rain in a given period.
Reducing-coupling. A fitting for connecting two sizes of threaded pipe.
Resistance. The force that a pump has to work against, caused by gravity, friction, head of water, etc.
Reducing Coupling.
Right-hand Thread. A screw thread in which, with the threaded end of the bolt towards you, the top of the nut must revolve from left to right like the hands of a watch, in order to cause the nut to screw upon the bolt.
Rope-socket. A device fastened to the end of a rope by means of which the rope may be attached to its load. The socket may be open or closed.
Rust-joint. A joint which is made by being filled with sifted cast-iron borings, mixed with sal ammoniac, sulphur and water; this causes the cuttings to rust and form a solid cement.
Rope Sockets.
Sea Injection. The pipe and valve through which sea water is injected into the condenser of a marine engine.
Screw Jacks.
Screw jack or lifting jack. A screw working in a threaded base or stationary nut and turned by a lever inserted into holes near the top, of which there are usually four. A loose plate or swivel is placed on top of screw.
“Slams” and “Shocks.” Banging, clanking and jarring noises indicating a derangement of the action of a pump.
Sleeve Coupling.
Sleeve-coupling. A threaded connection for uniting the two ends of pipes of equal size.
“Slippage.” The difference between the calculated and actual work performed by a pump.
Sluice. A water-gate; a channel to run off waste water.
Slurry pump. A special pump for handling a mixture of earth water.
Socket-wrench. A wrench for turning nuts, having a socket in the end made to a special size and shape of the nut to be turned.
Spanner. Is a wrench for turning round nuts having holes or slots.
Spanner.
Spline or feather. A key made fast in a shaft.
Split-pin or cutter. An iron pin divided at the end which is to be spread apart after inserting in the hole.
“Spread.” A term used to indicate the distance from center to center of the cylinders of a duplex pump.
Spring-seat. An elastic seat for a valve.
Steam thrown valves. Valves moved by steam only.
Steam end of a pump. The end operated by steam.
“Sticking of valves.” Inability to work caused by the introduction into the valves of sand, soil, etc.; or it may be caused by too tight a fit of the moving parts, rust or corrosion.
Street Elbow.
Street elbow. An elbow having an extension piece at one end.
“Stroke” of pump. The distance traveled by the piston in one motion.
Stud-Bolt.
Stud-bolt. A piece of round bar metal with a thread upon each end. A represents thread for nut; B body of bolt and C thread to fit in casting.
Stub-end. Either end of a connecting rod.
Strainer. A device for separating solid particles from the liquid which contains them.
Stuffing box. A recess to receive the packing around piston rods, plungers and valve stems.
Submerged pump. A pump which works under water.
Stub-End.
Strainer.
“Sucking wind.” A leakage of air into the suction part of a pump.
Supplemental piston. The piston which operates the main valve in the steam pump.
Swing check valve. One which swings upon a pivot or hinge in opening and closing.
Switch cock or valve. A device for conducting exhaust steam into the smoke stack or atmosphere. A three-way cock.
Syphon Cock. A cock having a combined chamber which is partially filled with water of condensation, attached to a steam gauge to keep steam from entering and damaging the works of the instrument.
Swing Check Valve.
Switch Cock.
Syphon Cock.
Thumb-Nut.
Thumb-nut. The same as a wing-nut, but a smaller size of the two, shown above, applied to hand-vice.
Tobin-bronze. An alloy of copper, tin and zinc treated in a special manner; it is non-corrosive, has great tensile strength and can be forged at a cherry red heat.
“Trailing Water.” Water can be trailed, i.e., carried through pipes to pumps a very great distance so long as “the lift” is not over 25 to 33 feet.
“Trompe.” The term used to designate a water-blast—a form of pump.
Turbine. A water wheel driven by the impact or reaction of streams of water flowing through it or by the impact and reaction combined; it is also distinguished by the manner in which it discharges the water, as outward, vertical or central discharge turbine wheels.
Turbine-pump. A pump in which water is raised by the action of a turbine wheel driven by exterior power in the opposite direction from that in which it is turned when used as a motor.
Tube-Plug.
Tube-plug. A tube stopper to be used in case of a leak in a boiler tube; it consists of two wood pistons joined together so that the leak will come between them. Tube plugs are frequently made of turned tapered cast iron, one of which is to be driven into each end of a leaking tube.
Union.
Union. A fitting designed to unite the two screwed ends of a pipe, with a single nut to secure them.
Vacuum. A void space; an inclosed chamber from which the air (or other gas) has been very nearly removed, as by an air pump.
Valve. Any device or appliance used to control the flow of a liquid, vapor, or gas, or loose material, through a pipe, outlet or inlet; the term includes air, gas, steam and water-cocks of all kinds; water-gates, air-gates, etc. One hundred and fifty of such devices are named by Knight in his “Mechanical Dictionary.”
Viscosity. Glutinous, adhering, or sticky, as tar, gums, molasses. Internal friction or resistance to change of shape.
V thread. A thread on a rod or bolt cut in the form of a letter V.
Washer. A circular piece of leather, rubber, metal, or other material with a hole in its center, through which a rod or bolt may pass.
Water Arch. A chamber of plates or of pipes over the furnace door of brick set boilers to take the place of the usual cast iron or fire brick arch, and connected with the boiler to supply it with water. The feed water is often introduced through the water arch.
Water-bellows. A form of pump, like a bellows—of great antiquity.
Water-cap. The cover for discharge valves on a steam pump.
Water-end. The pump end of a steam-pump; in distinction from the steam end.
Water-hammer. A noise caused by the pulsative motion of water inside a steam pipe, resembling the blows of a hammer.
Water Ram. A hydraulic ram.
Working Barrel. The water end of a pump.
Yoke.
Whirlpool-chamber. A chamber attached to the discharge end of the centrifugal pump in which the whirling water gradually loses its rotation, thereby reducing friction.
Wing-nut. An iron nut having a wing at each side. Sometimes called a “butterfly nut.”
Yoke. A branch pipe, or a two-way coupling for pipes, particularly twin hot and cold-water pipes that unite in their discharge.
Y.—A pipe fitting for uniting two pipes at an angle of 45°.