Penetration (Weld):

The percentage of wall thickness of the two parts to be joined that is fused into the weld pool in making a joint, our standard for penetration of the weld is 100%, in which the weld goes completely through the parent metal of the parts to be joined and is visible on the opposite side from which the weld was made.

Percent of Braid Coverage:

The percent of the surface area of a hose that is covered by braid.

Permanent Bend:

A short radius bend in a hose assembly used to compensate for misalignment of rigid piping, or where the hose is used as an elbow, hose so installed may be subjected to minor and/or infrequent vibration or movement.

Pipe Gap:

The open space between adjacent ends of two pipes in which a hose assembly may be installed.

Pitch:

The distance between the two peaks of adjacent corrugation.

Ply, Plies:
The number of individual thicknesses of metal used in the construction of the wall of a corrugated hose.

Pressure:

Usually expressed in pounds per square inch (PSI) and, depending on service conditions, may be applied internally or externally to a hose.

a. Absolute Pressure - A total pressure measurement system in which atmospheric pressure (at sea level) is added to the gage pressure, and is expressed as PSIA

b. Atmospheric Pressure - The pressure of the atmosphere at sea level which is 14.7 PSI, or 29.92 inches of mercury.

c. Burst Pressure (Actual and Rated)

1. Actual - Failure of the hose determined by the laboratory test in which the braid fails in tensile, or the hose ruptures, or both, due to the internal pressure applied; this test is usually conducted at room temperature with the assembly in a straight line, but for special applications, can be conducted at elevated temperatures and various configurations.
2. Rated - A burst value which may be theoretical, or a percentage of the actual burst pressure, developed by laboratory test; it is expected that, infrequently, due to manufacturing limitations, an assembly may burst at this pressure, but would most often burst at a pressure greater than this

d. Deformation Pressure (Collapse) - The pressure at which the corrugations of a hose are permanently deformed due to fluid pressure applied internally, or, in special applications, externally

e. Feet of Water or Head Pressure - Often used to express system pressure in terms of water column height, a column of water 1 ft. high exerts a .434 PSI pressure at its base

f. Proof Pressure or Test Pressure - The maximum internal pressure which a hose can be subjected to without either deforming the corrugations, or exceeding 50% of the burst pressure, when a hose assembly is tested above 50% of its burst pressure, there often is a permanent change in the overall length of the assembly, which may be undesirable forcertain applications

g. PSIA - Pounds per square inch absolute

h. PSIG - Pounds per square inch gauge

i. Pulsating Pressure - A rapid change in pressure above and below the normal base pressure, usually associated with reciprocating type pumps, this pulsating pressure can cause excessive wear between the braid and the tops of the hose corrugations

j. Shock Pressure - A sudden increase of pressure in a hydraulic or pneumatic system, which produces a shock wave. This shock can cause severe permanent deformation of the corrugations in a hose, as well as rapid failure of the assembly due to metal fatigue

k. Static Pressure - A non-changing constant pressure

l. Working Pressure - The pressure, usually internal, but sometimes external, imposed on a hose during operating conditions

Pressure Carrier:

The hose portion of a braided assembly.

Profile:

To the contour rolled into strip during the process of manufacturing stripwound hose, or the finished shape of a corrugation ;formed from a tube by either the “bump-out”, “sink”, or roll forming processes, used in making corrugated hose.

Random Motion:

The non-cyclic uncontrolled motion of a metal hose, such as occurs in manual handling.

Reusable Fitting
(See Mechanical Fitting)

Safety Factor:

The relationship of working pressure to burst pressure.

Scale:

Generally refers to the oxide in a hose assembly brought about by surface conditions or welding, an oxide.

Seamless:

Used in reference to a corrugated metal hose made from a base tube that does not have a longitudinal seam as in the case of a butt welded or lap welded tube.

Squirm:
A form of failure in which the hose is deformed into an “S” or “U” bend as the result of excessive internal pressure being applied to unbraided corrugated hose while its ends are restrained, or in a braided corrugated hose which has been axially compressed, loosening the braid, while the hose is pressurized, this is particularly true with long lengths of braided hose subjected to manual or mechanical handling.

Steep Braid (Angle):

Braid having a braid angle of less than 45°.

Strand(s):

Individual groups of wires in a braid, each group is supplied from a separate carrier in the braiding machine.

Stress Corrosion:

 A form of corrosion in stainless steel normally associated with chlorides.

Strip Wound
(See definition for Interlocked)

Tig Weld:

The tungsten inert gas welding process sometimes referred to as shielded arc. The common trade name is heliarc.

Traveling Loop:

A general classification of bending, wherein the hose is installed to a U-shaped configuration.

Class A Loop - An application wherein the radius remains constant and one end of the hose moves parallel to the other end of the hose

Class B Loop - A condition wherein a hose is installed in a U-shaped configuration and the ends move perpendicular to each other so as to enlarge or decrease the width of the loop

Torque (Torsion):

A force that produces, or tends to produce, rotation of or torsion through one end of a hose assembly while the other end is fixed.

Velocity:

The speed at which the medium flows through the hose, usually specified in feet per second.   

Velocity Resonance:

The sympathetic vibration of convolutions due to the buffeting of a high velocity gas or air flow.

Vibration:

Low amplitude motion occurring at high frequency.

Welding:

The process of localized joining of two or more metallic components by means of heating their surfaces to a state of fusion, or by fusion with the use of additional filler materials.