Braided Hose
Definition of Terms
Abrasion
External damage to a hose assembly caused by its being rubbed on a foreign
object.
Ambient Or Atmospheric Conditions
The surrounding conditions, such as temperature, pressure, and corrosion,
to which a hose assembly is exposed.
Amplitude Of Vibration And/Or
Lateral Movement
The distance a hose assembly deflects laterally to one side from its
normal position, when this deflection occurs on both sides of the normal
hose centerline.
Anchor
A restraint applied to a pipe line to control its motion caused by thermal
growth.
Annular
Refers to the convolutions on a hose that are a series of complete circles
or rings located at right angle to the longitudinal axis of the hose
(sometimes referred to as bellows).
Application
The service conditions that determine how a metal hose assembly will
be used.
Armor Or Casing
Flexible interlocked tubing placed over the entire length or in short
lengths at the end of a metal hose to protect it form physical damage
and to limit the bending radius.
Attachment
The method of fixing end fittings to flexible metal hose - welding,
brazing, soldering, swaging, or mechanical.
Axial Movement
Compression or elongation of the hose along its longitudinal axis.
Basket Weave
A braid pattern in which the strands of wire alternately cross over
and under two strands (two over - two under).
Bend Radius
The radius of a bend measured to the hose centerline.
Braid
A flexible wire sheath surrounding a metal hose that prevents the hose
from elongation due to internal pressure. Braid is composed of
a number of wires wrapped helically around the hose while at the same
time going under and over each other in a basket weave fashion.
Braid Angle
The acute angle formed by the braid strands and the axis of the hose.
Braid Make Up
term applies to description of braid, i.e. 36x8x.014,
304L SS,
where
36
= number of carriers, which equals the number of bands in a braid
8
= number of wires on each carrier
.014
= wire diameter in inches
304L SS
= material, Type 304L stainless steel
Braid Sleeve, Collar, Or
Ferrule
A ring, made from tube or metal strip placed over the ends of a braided
hose to contain the braid wires for attachment of fittings.
Braid Wear
Motion between the braid and corrugated hose which normally causes wear
on the O.D. of hose.
Braided Braid
In this braid. the strands of wire on each carrier of the braiding machine
are braided together, and then braided in normal fashion, hence the
term braided braid.
Brazing
A process of joining metals using a non-ferrous filler metal, which
melts above 800° F, yet less than the melting of the "parent metals"
to be joined.
Butt Weld
A process in which the edges or ends of metal sections are butted together
and joined by welding.
Casing
(See Armor)
Controlled Flexing
Controlled flexing occurs when the hose is being flexed regularly, as
in connections to moving components. Examples, platten presses,
thermal growth in pipe work.
Convolution
The annular or helical flexing member in corrugated or stripwound hose.
Corrosion
The chemical or electro-chemical attack of a media upon a hose assembly.
Cycle-Motion
The movement from normal to extreme position and return.
Developed Length
The length of a hose plus fitting (overall) required to meet the conditions
of a specific application.
Plain Weave
A braid pattern in which the strands alternately cross over one and
under one of the strands (one over - one under). Also known as
plain weave.
Dye Penetrant Inspection
Or Test
A method for detecting surface irregularities, such as cracks, voids,
porosity, etc. The surface to be checked is coated with a red
dye that will penetrate existing defects. Dye is removed from
surface and a white developer is applied. If there is a defect
in the surface being checked, the red dye remaining in it causes the
white developer to be stained. thereby locating the defective area.
Displacement
The amount of motion applied to a hose defined as inches for parallel
offset and degrees for radial misalignment.
Dog-Leg Assembly
Two hose assemblies joined by a common elbow/
Duplex Assembly
An assembly consisting of two hose assemblies - one inside the other
- and connected at the ends.
Effective Thrust Area -
Hose and Bellows
The cross-sectional area described by the outside diameter (at the tops
of the convolutions) less two times the metal thickness of the hose
or bellows.
Elastic
(Intermittent Flexure)
The smallest radius that a given hose can be bent to without permanent
deformation of the metal in its flexing members (convolutions or
corrugations).
Erosion
The wearing away of the inside convolutions of a hose caused by the
flow of the media conveyed, such as wet steam, abrasive particles, etc.
Fatigue
Failure of the metal structure associated with, or due to, the flexing
of metal hose or bellows.
Ferrule
(See Braid Sleeve)
Fitting
A loose term applied to the nipple, flange, union, etc., attached to
the end of a metal hose.
Flat Braid
Has a braid angle greater than 45° (See Braid Angle).
Flow Rate
Pertains to a volume of media being conveyed in a given time period,
e.g., cubic feet per hour, pounds per second, gallons per minute, etc.
Frequency
The rate of vibration or flexure of a hose in a given time period,
e.g., cycles per second (CPS), cycles per minute (CPM), cycles per day
(CPD), etc.
Galvanic Corrosion
Corrosion that occurs on the less noble of two dissimilar metals in
direct contact with each other in an electrolyte, such as water, sodium
chloride in solution, sulphuric acid, etc.
Guide
(For Piping)
A device that supports a pipe radially in all directions, but allows
free longitudinal movement.
Hardware
A loose term used to describe parts of a hose assembly other than the
hose and braid, e.g., fittings, collars, valves, etc.
Helical
Used to described a type of corrugated hose having one continuos convolution
resembling a screw thread.
Helical Wire Armor
To provide additional protection against abrasion under rough operating
conditions, metal hoses can be supplied with an external round or oval
section wire spiral.
Inside Diameter
This refers to the free cross section of the hose and (in most cases)
is identical to the nominal diameter..
Installation
Referring to the installed geometry of a hose assembly.
Interlocked Hose
Formed from profiled strip and wound into flexible metal tubing with
no subsequent welding, brazing, or soldering. May be made pressure-tight
by winding in strands of packing.
Intermittent Bend Radius
The designation for a radius used for non-continuous operation. Usually
an elastic radius.
Lap Weld
(LW)
Type of weld in which the ends or edges of the metal overlap each other
and are welded together.
Liner
Flexible sleeve used to line the I.D. of hose when the velocity of gaseous
media is in excess of 150 ft. per second.
Live Length
The amount of active (exposed) hose in an assembly.
Does not include the length of fittings and ferrules.
Loop Installation
The assembly is installed in a loop or "U" shape, and is most
often used when frequent and/or large amounts of motion are involved.
Mechanical Fitting Or Reusable
Fitting
A fitting not permanently attached to a hose which can be disassembled
and used again.
Medium (Singular)/Media
(Plural)
The substance(s) being conveyed through a piping system.
Minimum Bend Radius
The smallest radius to which a hose can be bent without suffering permanent
deformation of its convolutions.
Misalignment
A condition in which two points, intended to be connected, will not
mate due to their being laterally out of line with each other.
Nominal Diameter
A term used to define the dimensions of a component. It indicates the
approximate inside diameter.
O.E.M.
Original Equipment Manufacturer.
Offset - Lateral, Parallel,
& Shear
The amount that the ends of a hose assembly are displaced laterally
in relation to each other as the result of connecting two misaligned
terminations in a piping system, or intermittent flexure required in
a hose application.
Operating Conditions
The pressure, temperature, motion, media, and environment that a hose
assembly is subjected to.
Outside Diameter
This refers to the external diameter of a metal hose, measured from
the top of the corrugation or braiding.
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 10096, 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 thickness' 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.
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
500~ of the bunt 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 for certain 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.
1. 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
Used in reference 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 corrugated metal hose which is 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
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 airflow.
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.
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