_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.
[Illustration: 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.
[Illustration: 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.
[Illustration: BIBB-COCK.]
[Illustration: 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.
[Illustration: 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.”
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: GATE VALVE.]
[Illustration: 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.
[Illustration: 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._ A lifting device in which a ram, a pump, and liquid
is used instead of a screw.
[Illustration: HYDRAULIC JACK.]
_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.
_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.
[Illustration: MISSISSIPPI RIVER GAUGE COCK.]
_“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.
[Illustration: NIPPLE.]
_Outboard delivery pipe._ The pipe which leads, in steam vessels,
from the condenser through the side of the ship.
_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.
_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.
[Illustration: PITCHER PUMP.]
_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.
[Illustration: PLUMB BOB.]
_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.
[Illustration: PRESSURE REDUCING VALVE.]
[Illustration: SECTION.]
_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.
_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.
[Illustration: REDUCING COUPLING.]
_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.
_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.
[Illustration:
OPEN. ROPE SOCKETS. CLOSED.
]
_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.
_Sea Injection._ The pipe and valve through which sea water is
injected into the condenser of a marine engine.
_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.
[Illustration: SCREW JACKS.]
_“Slams” and “Shocks.”_ Banging, clanking and jarring noises
indicating a derangement of the action of a pump.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: STUB-END.]
_Stub-end._ Either end of a connecting rod.
[Illustration: STRAINER.]
_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.
“_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.
[Illustration: SWING CHECK VALVE.]
_Swing check valve._ One which swings upon a pivot or hinge in
opening and closing.
[Illustration: SWITCH COCK.]
_Switch cock or valve._ A device for conducting exhaust steam into
the smoke stack or atmosphere. A three-way cock.
[Illustration: SYPHON 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
_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.”
[Illustration: YOKE.]
_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°.