RADIATOR-- A coil in a steam or hot water system, or
may be either tapered or straight, depending upon
some similar device, that radiates or sends forth heat.
the requirements of the specific job.
RADIATOR VALVE--An angle valve fitted to a
PIPE VISE--A special type of vise with three serrated
steam or hot water heating radiator.
jaws, one of which moves against the other two, and
may be forced against the pipe by means of a screw
RADIUS OF BEND--The distance from the center
line of a pipe or fitting to the center of curvature.
PIPE WRENCH--A wrench arranged to grip with
RAISED FACE FLANGE--A type of flange that has
increasing pressure as force is exerted on the
a raised face, to a height of l/l6 to l/4 inch, inside
handle; the jaws of the wrench are usually serrated.
the bolt circle of the flange. The gasket is fitted to
this raised portion.
PIPING--The whole system of piping aboard ship.
REAMED-- A term meaning that burrs left by the
The term is also applied to a section of a system.
action of cutting-off tools have been removed.
PITCH-- Distance measured on a line parallel to the
REAMING-- Enlarging a hole by revolving in the hole
axis, and between two adjacent threads or two
a cylindrical, slightly tapered tool with cutting
convolutions of a screw.
edges running along its sides.
PLASTICITY-- That property that enables a material
to be excessively and permanently deformed
means that they are counterbored for a short
distance; as applied to flanges, it means that they
PLUG--Without a qualifying adjective, this term is
are provided with a calking recess at the back.
used to designate an ordinary plug or pipe plug with
REDUCER--A fitting larger at one end than at the
an exterior thread and a projecting head by which
other, and designed to conduct flow from one size
it is screwed into the opening of a fitting.
pipe to another of different diameter. Reducers
PLUG COCK--Usually called simply a cock. All
have inside threading unless specified for a flange
cocks are essentially plug cocks.
or for some special joint. The threaded type is made
with abrupt reduction. The flanged type has a
PLUG TAP--A tap with the threaded portions straight
or without lead, and designed for bottoming.
REDUCING TEE--A tee with two different sized
POROSITY-- State of being full of pores or holes, like
openings. It may reduce on a branch or on the main
a sponge. A defect commonly found in weld metal.
PREHEATING-- The application of heat to base metal
REDUCING VALVE--A spring-loaded or
before it is welded or cut to bring it to a minimum
lever-loaded valve similar to a safety valve,
temperature or working temperature.
designed to maintain a lower end constant pressure
beyond the valve.
PROTECTOR-- A ring threaded on its inside and used
to protect the threaded end of pipe during transit.
RETURN BEND--In general, this term signifies a
fitting with inside threads that changes the direction
PUNCH-- A machine for punching holes in plates and
of piping by 180 degrees.
RISER--A pipe extending vertically with side
PUNCH, PRICK--A small punch used to transfer
holes from a template to a plate. Also called a
RIVET--A metal pin used to connect two or more
pieces of material. The rivet is inserted into holes
PLYWOOD-- A building material consisting usually
punched or drilled in the pieces and upset at one or
of an odd number of veneers glued over each other
both ends. The end that bears a finished shape is
at right angles.
called the head and the end upon which some
PYROMETER--An instrument used to measure the
operation is performed after its insertion is called
temperature of metal and used in the welding
the point. Small rivets are "driven cold," that is,
process to determine preheat and interpass
without heating, and large ones are heated so that
points may be formed by hammering.