Installation Guide

Hoop Stress The circumferential stress imposed on a

pipe wall when exposed to an internal pressure load.

Usually expressed in PSI.

Impact Strength A measure of a plastic part’s ability to

withstand the effects of dropping and/or striking. There are

two commonly used test methods, Notched Izod and Tup.

Notched Izod uses a pendulum-type machine to strike a

notched specimen. Tup testing uses a falling weight (tup)

to strike a pipe or fitting specimen.

Injection Molding The process used to form a shape by

forcing a heated plastic, in a fluid state and under pressure,

into the cavity of a closed mold.

Joint The point where a pipe and fitting or two pieces of

pipe are connected together.

Lubricant Any substance which reduces the friction

between moving solid surfaces.

Modulus A term used to describe the load required

to cause a specified percentage of elongation. It is usually

expressed in PSI or kilograms per square centimeter.

Non-flammable Incapable of supporting combustion.

Plastic A material that contains as an essential ingredient

one or more organic polymeric substances of large molecular

weight, is solid in its finished state, and, at some stage in

its manufacture or in its processing into finished articles,

can be shaped by flow.

Plastic Pipe A hollow cylinder of a plastic material

in which the wall thicknesses are usually small when

compared to the diameter and in which the inside and

outside walls are essentially concentric.

Plasticizer A substance incorporated in a plastic to

increase its workability, flexibility or distensibility.

Glossary