Design, Specification, & Installation
Glossary & Conversion Factors
Glossary of Terms
A - B | C - D | E - F | G - I | J - O | P - R | S - Z
Adhesive
A substance capable of holding materials together by surface
attachment.
Aging
1) The effect on materials of exposure to an environment
for an interval of time.
2) The process of exposing materials to an environment for an interval
of time.
Apparent Density
The weight per unit volume of a material including voids
inherent in the material as tested.
Beam Loading
The application of a load to a pipe between two points
of support, usually expressed in newtons (or pounds-force) and the
distance between the centers of the supports.
Bell End
The enlarged portion of a pipe that resembles the socket
portion of a fitting and is used to make a joint.
Burst Strength
The internal pressure required to cause a pipe or fitting
to fail.
Note: This pressure will vary with the rate of buildup of the pressure
and the time during which the pressure is held.
Chemical Resistance
The ability to resist chemical attack.
Note: The attack is dependent on the method of
test, and its severity is measured by determining the changes in
physical properties. Time, temperature, stress, and reagent may
all be factors that affect the chemical resistance of a material.
Cleaner, Chemical
An organic solvent used to remove foreign matter from the
surface of plastic pipe and fittings.
Cleaner, Mechanical
An abrasive material or device used to remove foreign matter
and gloss from the surface of plastic pipe and fittings.
Note: Mechanical cleaners may be used prior to
joining with a solvent cement or adhesive.
Code, Thermoplastic Pipe Materials Designation
A code for pressure pipe that consists of two or three
letters that indicate the kind of thermoplastic followed by two
numerals that designate the type and grade of thermoplastic and
two numerals that designate the hydrostatic design stress in units
of 100 psi with any decimal figures dropped.
Note: For example, CPVC 4120
Compound
A mixture of a polymer with other ingredients such as fillers,
stabilizers, catalysts, processing aids, lubricants, modifiers pigments,
or curing agents.
Compression Molding
The method of molding a material in a confined cavity by
applying pressure and usually heat.
Conduit
A tubular raceway for carrying electric wires, cables,
or other conductors.
Contamination
The presence of a substance not intentionally incorporated in a
product.
Crack
Any narrow opening or fissure in the surface that may or
may not be visible to the naked eye.
Crazing
Apparent fine cracks at or under the surface of a plastic.
Deflection Temperature
The temperature at which a specimen will deflect a given distance
at a given load under prescribed conditions of test. Formerly called
heat distortion.
Degradation
A deleterious change in the chemical structure of a plastic.
Diffusion
The movement of a material such as a gas or liquid, in the body
of a plastic.
Note: If the gas or liquid is absorbed on one
side of a piece of plastic and given off on the other side, the
phenomenon is called permeability. Diffusion and permeability are
not due to holes or pores in the plastic.
Dimension Ratio
The average specified diameter of a pipe divided by the
minimum specified wall thickness.
Elastomer
A polymer that returns to approximately its initial dimensions
and shape after substantial deformation by a weak stress and release
of the stress.
Elevated Temperature Testing
Tests on plastic pipe above 23°C (73°F).
Environmental Stress Cracking
The development of cracks in a material that is subjected
to stress or strain in the presence of specific chemicals. The degree
of cracking may be measured by visible crack evidence or by retention
of mechanical properties in the exposed thermoplastic part.
Extrusion
A process whereby heated plastic forced through a shaping
orifice becomes one continuously formed piece.
Fabricating
The manufacture of plastic products from molded parts,
rods, tubes, sheeting, extrusions, or other forms by appropriate
operations such as punching, cutting, drilling, and tapping including
fastening plastic parts together or to other parts by mechanical
devices, adhesives, heat sealing, or other means.
Filler
A relatively inert material added to a plastic to modify
its strength, permanence, working properties or other qualities
or to lower costs.
Fitting
A piping component used to join or terminate sections of
pipe or to provide changes of direction or branching in a pipe system.
Fuse
1) To convert plastic powder or pellets into a a homogeneous
mass through heat and pressure.
2) To make a plastic piping joint by heat and pressure.
Glass Transition
The reversible change in an amorphous polymer or in amorphous
regions of a partially crystalline polymer from a hard condition
to a rubbery condition as its temperature is increased.
Glass Transition Temperature (Tg)
The approximate midpoint of the temperature range over
which the glass transition takes place. The glass transition temperature
is the determining feature of the deflection temperature.
Heat Joining
Making a joint by heating the mating surfaces of the pipe
components to be joined and pressing them together so that they
fuse and become essentially one piece.
Note: Also known as heat fusion, thermal fusion,
and fusion.
Hoop Stress
The tensile stress in the wall of the pipe in the circumferential
orientation due to internal hydrostatic pressure.
Note: Hydrostatic means fluid and is not limited
to water.
Hydrostatic Design Stress
The recommended maximum hoop stress that can be applied
continuously with a high degree of certainty that failure of the
pipe will not occur.
Impact, Izod
A specific type of impact test made with a pendulum type machine
on a cantilever beam specimen and also the values obtained by this
method.
Impact, Drop Weight
A falling weight (tup) impact test developed specifically
for pipe and fittings.
Injection Molding
The process of forming a material by forcing it, under
pressure, from a heated cylinder through a sprue (runner, gate)
into the cavity of a closed mold.
Joint
The location at which two pieces of pipe or a pipe and
fitting are connected together.
Note: The joint may be made by an adhesive, a
solvent-cement, heat joining, or a mechanical device such as threads
or a ring seal.
Long-Term Hydrostatic Strength (LTHS)
Hoop stress that when applied continuously will cause failure
of the pipe at 100 000 h (11.43 years).
Note: These strengths are usually obtained by
extrapolation of log-log regression equations or plots. Typical
conditions are water at 23°C.
Lubricant
1) A material used to reduce the friction between two mating
surfaces that are being joined by sliding contact.
2) An additive that is added to a plastic compound to lower the
viscosity or otherwise improve the processing or product characteristics.
Monomer
A relatively simple organic compound which can react to
form a polymer.
Plasticizer
A substance incorporated in a material to increase its
workability, flexibility or extensibility.
Polymer
A substance consisting of very large molecules characterized
by the repetition of one or more types of monomeric units.
Pressure Rating
The estimated maximum pressure that the medium in the pipe
can exert continuously with a high degree of certainty that failure
of the pipe will not occur.
Primer
An organic solvent, which enhances adhesion, applied to
plastic pipe and fittings prior to application of a solvent cement.
Quick Burst Pressure
The internal pressure required to bring a piping component
to failure when subjected to a quick burst test.
Resin
The powder form of a polymer.
Schedule
A pipe size system (outside diameters and wall thicknesses)
originated by the iron pipe industry.
Solvent Cement
An adhesive made by dissolving a plastic resin or compound
in a suitable solvent or mixture of solvents. The solvent cement
dissolves the surfaces of the pipe and fittings to form a bond between
the mating surfaces provided the proper cement is used for the particular
materials and proper techniques are followed.
Strain
The change per unit of length in a linear dimension of
a body, that accompanies a stress.
Strength
The stress required to break, rupture, or cause a failure.
(flex strength is not a measure of a failure mode)
Stress Relaxation
The decrease in stress, at constant strain, with time.
Conversion Factors
| TO CONVERT FROM | TO | MULTIPLY BY |
| LENGTH | ||
| Centimeters | Inches | 0.39370079 |
| Inches | Centimeters | 2.54 |
| Meters | Feet | 3.2808399 |
| Feet | Meters | 0.3048 |
| MASS | ||
| Kilograms | Pounds | 2.2046226 |
| Pounds | Kilograms | 0.45359237 |
| FORCE | ||
| Newtons | Pounds | 0.22480894 |
| PRESSURE | ||
| Atmospheres | Bars | 1.01325 |
| Atmospheres | PSI | 14.6959488 |
| Bars | Atmospheres | 0.986923 |
| Bars | PSI | 14.5038 |
| Feet of water (4C) | PSI | 0.433515 |
| Kilograms/sq. cm | Bars | 0.980665 |
| Kilograms/sq. cm | PSI | 14.223343 |
| PSI | Atmospheres | 0.0680460 |
| PSI | Bars | 0.0689476 |
| AREA | ||
| Square centimeters | Square inches | 0.15500031 |
| Square feet | Square meters | 0.09290304 |
| Square inches | Square centimeters | 6.4516 |
| Square meters | Square feet | 10.763910 |
| VOLUME | ||
| Cubic centimeters | Cubic inches | 0.061023744 |
| Cubic feet | Gallons | 7.4805195 |
| Cubic feet | Liters | 28.316847 |
| Cubic inches | Cubic centimeters | 16.387064 |
| Cubic inches | Cubic feet | 0.0005787037 |
| Cubic meters | Cubic feet | 35.314667 |
| Cubic meters | Gallons | 264.17205 |
| Gallons | Cubic feet | 0.133680555 |
| Gallons | Liters | 3.7854118 |
| Liters | Cubic feet | 0.035314667 |
| Liters | Gallons | 0.26417205 |
| DENSITY | ||
| Grams/cubic centimeter | Pounds/gallon | 8.3454044 |
| Pounds/gallon | Grams/cubic centimeter | 0.11982643 |
| ENERGY | ||
| BTU | Foot-pounds | 777.649 |
| BTU | Joules | 1054.35 |
| BTU | Kilowatt-hours | 0.000292875 |
| Foot-pounds | BTU | 0.0012859 |
| Foot-pounds | Joules | 1.35582 |
| POWER | ||
| BTU/min | Horsepower | 0.0235651 |
| BTU/min | Joules/second (Watts) | 17.5725 |
| Horsepower | BTU/min | 42.4356 |
| Horsepower | Kilowatts | 0.7457 |
| Kilowatts | BTU/min | 56.9072 |
| Kilowatts | Horsepower | 1.34102 |
