The following is a glossary of terms commonly used in the hose and fittings industry for the hydraulic sector. However, such words and expressions should not be intended as only with the precise meaning exposed in all the circumstances.
The following is a glossary of terms commonly used in the hose and fittings industry for the hydraulic sector. However, such words and expressions should not be intended as only with the precise meaning exposed in all the circumstances.
Abrasion: a wearing away by friction.
Abrasion tester: a machine for determining the quantity of material worn away by friction under specified conditions.
Accelerated life test: a method designed to approximate in a short time the deteriorating effects obtained under normal service conditions.
Accelerator: a compounding ingredient used with a curing agent to increase the rate of vulcanization.
Acid resistant: having the capability to withstand the action of identified acids within specified limits of concentration and temperature.
Activator: a compounding ingredient used to increase the effectiveness of an accelerator.
Adapter: the accessory part which can complete the connection between a hose fitting and another fluid system component. Often, a tube fitting connected to a hose.
Alloy: metal made of the fusion of two or more metals.
Annealing: thermal treatment process, which consist of heating a metallurgical product at a sufficient temperature to recover some or all of its structural and physical-chemical balance, and then gradually cooling it.
Adhesion: the strength of bond between cured rubber surfaces or between a cured rubber surface and a non-rubber surface.
Adhesion failure: the separation of two bonded surfaces at an interface by a force less than specified in a test method or the separation of two adjoining surfaces owing to service conditions.
Adhesive: a material which, when applied, will cause two surfaces to adhere.
Adhesive coating: a layer applied to any product surface to increase its adherence to an adjoining surface.
Aftercure: a continuation of the process of vulcanization after the cure has been carried to the desired degree and the source of heat removed.
Afterglow: in fire resistance testing, the red glow persisting after extinction of the flame.
Aging: changes in physical properties over a period of time.
Air cure: vulcanization without the application of heat. See also: hot air cure.
Air oven aging: a means of accelerating a change in the physical properties of rubber compounds by exposing them to the action of air at an elevated temperature at atmospheric pressure.
Ambient temperature: the temperature of the atmosphere or medium surrounding an object under consideration.
Angle of lay: the angle developed at the intersection of a structural element and a line parallel to its lineal axis.
Antioxidant: a compounding ingredient used to retard deterioration caused by oxygen.
Anti-ozonant: a compounding ingredient used to retard deterioration caused by ozone.
Anti-static: having the capability of furnishing a path for a flow of static electricity.
Armored hose: a hose with a protective covering, applied as a braid or helix, to protect from physical abuse.
Assembly: hose assembly.
Autoclave: a pressure vessel used for vulcanizing rubber products by means of steam under pressure.
Banbury mixer: a specific type of internal mixer used to incorporate fillers and other ingredients into rubber or plastic.
Band: a thin strip of metal used as a boltless clamp.
Bank: an accumulation of material at the opening between the rolls of a mill or calender.
Batch: the product of one mixing operation.
Bench marks (tensile test): marks of known separation applied to a specimen used to measure strain (elongation of specimen).
Bench test: modified service test in which the service conditions are approximated in the laboratory.
Bend: the curvature of a hose from a straight line.
Bending force: an amount of stress required to induce bending around a specified radius and hence, a measure of stiffness.
Bend radius: the radius of a bent section of hose measured to the innermost surface of the curved portion.
Bleeding: surface exudation. See also: bloom.
Blister: a raised area on the surface or a separation between layers usually creating a void or air-filled space in a vulcanized article.
Bloom: a discoloration or change in appearance of the surface of a rubber product caused by the migration of a liquid or solid to the surface.
Body wire: a round or flat wire helix embedded in the hose wall to increase strength or to resist collapse.
Bolt hole circle: a circle on the flange face around which the centre of the bolt holes are distributed.
Bore: an internal cylindrical passageway, as of a tube, hose or pipe; the internal diameter of a tube, hose or pipe.
Braid: a continuous sleeve or reinforcement of interwoven single or multiple strands of yarn or wire.
Braid angle: the angle developed at the intersection of a braid strand and a line parallel to the axis of a hose.
Braid smash: a defect in a braided reinforcement caused by one or more of the ends of reinforcing material breaking during the braiding operation.
Braided hose: hose in which the reinforcing structure presents braided configuration.
Braided ply: a layer of braided reinforcement.
Braider: a machine which interweaves strands of yarn or wire to make a hose reinforcement.
Brand: a mark or symbol identifying or describing a product and/or manufacturer, embossed, inlaid or printed.
Breaker ply: an open mesh fabric used to anchor a hose tube or cover to its reinforcement and to spread impact.
Buckled ply: a deformation in a ply which distorts its normal plane.
Buffing: grinding a surface to obtain dimensional conformance or surface uniformity.
Burst: a rupture caused by internal pressure.
Burst pressure: the pressure at which rupture occurs.
Calender: a machine equipped with three or more heavy, internally heated or cooled rolls revolving in opposite directions, which is used for continuously sheeting or plying up rubber compounds or fractioning or coating fabric with rubber compound.
Capped end: a hose end covered to protect its internal elements.
Carcass: the fabric, cord and/or metal reinforcing section of a hose as distinguished from the hose tube or cover.
Cement: un-vulcanized raw or compounded rubber in a suitable solvent used as an adhesive or sealant.
Cemented end: a hose end sealed with the application of a liquid coating.
Circular woven jacket: a textile reinforcing member produced on a circular loom for such types of hose as fire hose.
Clamp: in hose, a metal fitting or band used around the outside of a hose end to bind the hose to a coupling, fitting or nipple.
Cold flexibility: the relative ease of bending following exposure to specified low temperature conditions.
Compound: the mixture of rubber or plastic and other materials which are combined to give the desired properties when used in the manufacture of a product.
Compound ingredient: a material added to a rubber to form a mix.
Compression set: the deformation which remains in rubber after it has been subjected to and released from a specific ompressive stress for a definite period of time at a prescribed temperature.
Conditioning: the exposure of a specimen under specified conditions, e.g. temperature, humidity, for a specified period of time before testing.
Concentricity: the uniformity of hose wall thickness as measured in a plane normal to the axis of the hose.
Conductive: a rubber having qualities of conducting or transmitting heat or electricity (generally applied to rubber products capable of conducting static electricity).
Copolymer: a polymer formed from two or more types of monomers.
Corrugated cover: a longitudinally ribbed or grooved exterior.
Corrugated hose: hose with a carcass fluted radially or helically to enhance its flexibility or reduce its weight.
Coupling: a frequently used alternative term for fitting.
Cover: the outer component usually intended to protect the carcass of a product.
Cover wear: the loss of material during use due to abrasion, cutting or gouging.
Cracking: a sharp break or fissure in the surface, generally caused by strain and environmental conditions.
Crazing: a surface effect on rubber articles characterized by multitudinous minute cracks.
Creep: the deformation, in either cured or uncured rubber under stress, which occurs with lapse of time after the immediate deformation.
Crimped-back nut: the method used to realize the mechanical connection of the nut on the fitting by means of a crimping operation of the neck of the nut.
Crimping: the act of forming a hose fitting with a surrounding series of die segments to compress the hose within the fitting.
Crosshead extruder: an extruder so constructed that the axis of the emerging extruded product is at right angles to the axis of the extruder screw.
Cross-link: chemical bond bridging one polymer chain to another.
Cross wrap: the overlapping layer or layers of narrow tensioned wrapper fabric spiraled circumferentially over the outside of a hose to obtain external pressure during vulcanization.
Cure: the act of vulcanization.
Cure time: the time required to produce vulcanization at a given temperature.
Cut resistant: having that characteristic of withstanding the cutting action of sharp objects.
Date code: any combination of numbers, letters, symbols or other methods used by a manufacturer to identify the time of manufacture of a product.
Denier: a yam sizing system for continuous filament synthetic fibers.
Design factor: a ratio used to establish the working pressure of the hose based on the burst strength of the hose.
Dry: the absence of tack; no adhering properties.
Durometer: an instrument for measuring the hardness of rubber and plastic compounds.
Durometer hardness: a numerical value which indicates the resistance to indentation of the blunt indenter of the durometer.
Eccentricity: in hose, the condition resulting from the inside and outside diameters not having a common centre.
Eccentric wall: in hose or tubing, a wall of varying thickness.
Elastic limit: the limiting extent to which a body may be deformed and yet return to its original shape after removal of the deforming force.
Elastomer: a macromolecular material which, in the vulcanized state at room temperature, can be stretched repeatedly to at least twice its original length and which, upon release of the stress, will immediately return to approximately its original length.
Elongation: the increase in length expressed numerically as a fraction or percentage of the initial length.
End: a single strand or one of several parallel strands of a reinforcing material on a single package such as a braider spool.
Endurance test: a service or laboratory test, conducted up to product failure, usually under normal use conditions.
Extruded: forced through the shaping die of an extruder. The extrusion may be solid or hollow cross section.
Extruder (extrusion): a machine, generally with a driven screw, for continuous forming of rubber or plastic trough a die. It is widely used for the production of hoses.
Fabric: a planar structure produced by interlaced yams, fibers or filaments.
Fabric impression: a pattern in the rubber surface formed by contact with fabric during vulcanization (wrapped).
Fatigue: the weakening or deterioration of a material occurring when a repetitious or continuous application of stress causes strain.
Ferrule: a collar placed over a hose end to affix the fitting to the hose. The ferrule may be crimped or swaged, forcing the hose in against the insert.
Filler: any compounding material, usually in powder form, added to rubber in a substantial volume to improve quality or lower cost.
Fitting: a device attached to the end of the hose to facilitate connection.
Flange-fitting: a circular ring, at the end of a hose for joining to another circular ring, generally by bolting.
Flat spots: flat areas on the surface of cured hose caused by deformation during vulcanization.
Flex cracking: a surface cracking, induced by repeated bending and straightening.
Flexible mandrel: a long, round, smooth rod capable of being coiled in a small diameter. It is used for support during manufacture of certain types of hose.
Flex life: the relative ability of a rubber article to withstand cyclical bending stresses.
Flex life test: a laboratory method used to determine the life of a rubber product when subjected to dynamic bending stresses.
Flow rate: a volume of fluid per unit of time passing a given cross-section of a flow passage in a given direction.
Foreign material: any extraneous matter such as wood, paper, metal. Sand, dirt or pigment that should not normally be present in the tube or cover of a hose.
Formula: a list of ingredients and their amount, used in the preparation of a compound.
Free hose length: the lineal measurement of hose between fittings or couplings.
Friction: a rubber adhesive compound impregnating a fabric, usually applied by means of a calendar (also used to intend the resistance to motion due to the contact of surfaces).
Grab test: a tensile test for woven fabric using specimens considerably wider than the jaws holding the ends of the test specimen.
Grain: the unidirectional orientation of rubber or filler particles resulting in anisotropy of rubber compounds.
Ground finish: a surface produced by grinding or buffing.
Gum compound: a rubber compound containing only those ingredients necessary for vulcanization.
Small amounts of other ingredients may be added for processability, coloring, and improving resistance to aging.
Hardening: an increase in resistance to indentation.
Hardness: resistance to indentation.
Heat resistance: the property or ability to resist the deteriorating effects of elevated temperatures.
Helical cord: in hose, a reinforcement formed by a cord or cords wound spirally around the body of a hose.
Helix: in hose, a shape formed by spiraling a wire or other reinforcement around the cylindrical body of a hose.
Hold test: a hydrostatic pressure test in which the hose is subjected to a specified internal pressure for a specified period of time.
Hose: a flexible conduit consisting of a tube, reinforcement, and usually an outer cover.
Hose assembly: a length of hose with a coupling attached to one or each end.
Hose clamp: a collar, band or wire used to hold hose on to a fitting.
Hose duck: a woven fabric made from plied yams with approximately equal strength in warp and filling directions.
Hot air cure: vulcanization by using heated air, with or without pressure.
Hysteresis: a loss of energy due to successive deformation and relaxation. It is measured by the area between the deformation and relaxation stress-strain curves.
Hysteresis loop: in general, the area between stress-strain curves of increasing and reducing stress, a measure of hysteresis.
ID: the abbreviation for inside diameter.
Identification yarn: a yarn of single or multiple colors, usually embedded in the hose wall, used to identify the manufacturer.
Impregnation: the act of filling the interstices of an article with a rubber compound. Generally applies to the treatment of textile fabrics and cords.
Impression: a design formed during vulcanization in the surface of a hose by a method of transfer such as fabric impression or molded impression.
Impulse: an application of force in a manner to produce sudden strain or motion, such as hydraulic pressure applied in a hose.
Indentation: the extent of deformation by the indenter point of any one of a number of standard hardness testing instruments (sometimes used to intend a recess in the surface of a hose).
Inhibitor: an ingredient used to suppress a chemical reaction or a growing activity such as mildew.
Insert: optional term for nipple of a fitting (coupling).
Inspection block: a description on a drawing of the dimensional inspection to which a hose will be subjected.
Instantaneous modules: the slope of a stress-strain curve at a single point, employed when modules varies from point to point.
Interstice: a small opening, such as between fibers in a cord or threads in a woven or braided fabric.
Jacket: a seamless tubular braided or woven ply generally on the outside of a hose.
Kinking: a temporary or permanent distortion of the hose induced by bending beyond the minimum bend radius.
Knit fabric: a flat or tubular structure made from one or more yams or filaments whose direction is generally transverse to the fabric axis but whose successive passes are united by a series of interlocking loops.
Knit ply: a layer of textile reinforcement in which the yarns are applied in an interlocking looped configuration in a continuous tubular structure.
Knitter: a machine for forming a fabric by the action of needles engaging threads in such a manner as to cause a sequence of interlaced loops.
Laminated cover: a cover formed to desired thickness from thinner layers vulcanized together.
Lap: a part that extends over itself or like part, usually by a desired and predetermined amount.
Lap seam: a seam made by placing the edge of one piece of material extending flat over the edge of the second piece of material.
Lay: the amount of advance of any point in a strand for one complete turn.
Layer: a single thickness of rubber or fabric between adjacent parts.
Latch area: area of the fitting to provide mechanical connection with the ferrule.
Lead cure finish: a type of exterior surface of hose, smooth or longitudinally corrugated, obtained by the lead pipe method of vulcanization (old method).
Leakage: a crack or hole in the tube which allows fluid to escape, or a hose assembly which allows fluid to escape at the fittings or couplings.
Life test: a laboratory procedure used to determine the resistance of a hose to a specific set of destructive forces or conditions.
Light resistance: the ability to retard the deleterious action of light.
Lined hose: term generally referring to fire hose having a seamless woven jacket, or jackets and a tube.
Liner: a separator, usually cloth, plastic film or paper, used to prevent adjacent layers of material from sticking together. Also used as synonym of internal tube of a hose.
Lining: internal tube layer.
Livering: a gelling in cement giving a liver-like consistency.
Loose cover: a separation of the cover from the carcass or reinforcements.
Loose ply: a separation between adjacent plies.
Loose tube: a tube separated from the carcass.
Lot: a specified quantity of hose from which a sample is taken for inspection.
Low temperature flexibility: the ability of a hose to be flexed bent or bowed at low temperatures without loss of serviceability.
Low temperature flexing: the act of bending or bowing a hose under conditions of cold environment.
LPG: the abbreviation for liquefied petroleum gas.
Mandrel: a form, generally of elongated round section, used for size and to support hose during fabrication and/or vulcanization. It may be rigid for flexible.
Mandrel built: a hose fabricated and/or vulcanized on a mandrel.
Mandrel wrapped: a tubing, built up by wrapping a thick un-vulcanized sheet around a mandrel.
Manufacturer’s identification: a code symbol used on the hose to indicate the manufacturer.
Mass flow rate: the mass of fluid per unit of time passing a given cross-section of a flow passage in a given direction.
Master batch: a preliminary mixture of rubber and one or more compound ingredients for such purposes as more thorough dispersion or better processing, and which will later become part of the final compound in a subsequent mixing operation.
Migration: in a rubber compound, the movement of more or less rubber soluble materials from a point of high concentration to one of low or zero concentration. Migration is applied to the movement of accelerators, antioxidants, anti-ozonants, sulphur, softeners and organic colors. It is a form of diffusion.
Migration stain: a discoloration of a surface by a hose which is adjacent to but not touching the discolored surface.
Mildew inhibited: containing material to prevent or retard the propagation of a fungus growth.
Mildew resistance: withstanding the action of mildew and its deteriorating effect.
Mill: a machine with two horizontal rolls revolving in opposite directions used for the mastication or mixing of rubber.
Minimum burst pressure: the lowest pressure at which rupture occurs under prescribed conditions.
Modules: in the physical testing of rubber, the load necessary to produce a stated percentage of elongation, compression or shear.
Moisture absorption: the assimilation of water by a rubber or textile product.
Moisture regain: the re absorption of water by textile.
Monomer: a low molecular weight substance consisting of molecules capable of reacting with like or unlike molecules to form a polymer.
Mooney scorch: a measure of the incipient curing characteristics of a rubber compound using the Mooney viscometer.
Mooney viscosity: a measure of the plasticity of a rubber or rubber compound determined in a Mooney shearing disc viscometer.
MPa: Mega Pascal a measure of pressure, 1 MPa equal to 145 psi.
MSHA: Mine Safety and Health Administration
Necking down: a localized decrease in the cross-sectional area of a hose resulting from tension.
Nerve: a measure of toughness or recovery from deformation in unvulcanised rubbers or compounds.
Nip: the clearance between rolls of a mixing mill or calender.
Nipple: the internal member or portion of a hose fitting (insert).
Nominal: a dimensional value assigned for the purpose of convenient designation; existing in name only.
Nozzle end: an end of hose in which both the inside and outside diameters are reduced.
OD: the abbreviation for outside diameter.
Off gauge: not conforming to a specified thickness.
Oil proof: not affected by exposure to oil.
Oil swell: the change in volume of a rubber article resulting from contact with oil.
Open seam: a seam whose edges do not meet, creating a void.
Open steam cure: a method of vulcanizing in which steam comes in direct contact with the product being cured.
Operating pressure: like working pressure or maximum working pressure.
Optimum cure: the state of vulcanization at which a desired combination of characteristics is attained.
Overcure: a state of vulcanization beyond the optimum cure.
Oxidation: the reaction of oxygen on a rubber product, usually evidenced by a change in the appearance or in physical properties.
Oxygen bomb aging: a means of accelerating a change in the physical properties of rubber compounds by exposing them to the action of oxygen at an elevated temperature and pressure.
Ozone cracking: the surface cracks, checks or crazing caused by exposure to atmosphere containing ozone.
Ozone resistance: the ability to withstand the deteriorating effects of ozone (generally cracking).
Peptizer: a compounding ingredient used in small proportions to accelerate by chemical action the softening of rubber under the influence of mechanical action, heat, or both.
Permanent fitting: the type of fitting which, once installed, may not be removed for use in another hose.
Permanent set: the amount by which an elastic material fails to return to its original form after deformation.
Pick: an individual filling yarn of a fabric or woven jacket.
Pin-hole: very small hole, present on the tube surface of a hose as defect.
Pin-pricking: the small holes made by means of pins on the hose cover for gas applications.
Pitch: the distance from one point on a helix to the corresponding point on the next turn of the helix, measured parallel to the axis.
Pitted tube: surface depressions on the inner tube of a hose.
Pitting: superficial fatigue effect on metallic surfaces, creating surface depressions, corrosion.
Plain ends: the uncapped or otherwise unprotected, straight ends of a hose.
Plasticity: a measure of the resistance to shear of an unvulcanised elastomer; it is also used to indicate a property of vulcanized rubber to retain a shape or form imposed to it by a deforming force.
Plasticizer: a compounding ingredient which can change the hardness, flexibility, or plasticity of an elastomer.
Plastometer: an instrument for measuring the viscosity of raw or unvulcanised rubber.
Plied yarn: a yarn made by twisting together in one operation two or more single yarns.
Ply: a layer or rubberized fabric or a layer of reinforcement.
Ply adhesion: the force required to separate two adjoining reinforcing members of a hose.
Ply separation: a loss of adhesion between plies.
Pock marks: uneven blister-like elevations, depressions or pimpled appearance.
Polymer: a macromolecular material formed by the chemical combination of monomers having either the same or different chemical composition.
Porous tube: the physical condition of a hose tube due to the presence of pores or a hose tube that has low resistance to permeation.
Pre-cure: see semi-cure and scorch.
Pressure, burst: the pressure at which rupture occurs.
Pressure, operating: working pressure.
Pressure, proof: a specified pressure which exceeds the manufacturer’s recommended working pressure applied to a hose to indicate its reliability at normal working pressure. Proof pressure is usually twice the working pressure.
Pressure, service: generally to intend working pressure.
Pressure, working: the maximum pressure to which a hose will be subjected, including the momentary surges in pressure which can occur during service, it is often abbreviated as WP.
Pricker mark: a perforation of the cover of a hose performed before or after vulcanization.
Processability: the relative ease with which raw or compounded rubber can be handled in or on rubber processing machinery.
Proof pressure test: a non-destructive pressure test applied to a hose to determine its reliability at normal working pressures by applying pressures which exceed the manufacturer’s rated working pressure. Proof pressure is usually twice the working pressure.
Psi: the abbreviation for pounds per square inch.
Pulled-down tube: loose tube.
Pure gum: a rubber compound containing only those ingredients necessary for vulcanization; particularly applicable to natural rubber.
Qualification test: the examination of samples from a typical production run of hose to determine adherence to a given specification; performed for approval as a supplier.
Quality conformance inspection or test: the examination of samples from a production run of hose to determine adherence to given specifications, for acceptance of that production run.
Rag-wrap: for wrapped cure.
Recovery: the degree to which a hose returns to its normal dimensions or shape after being distorted.
Reinforcement: the strengthening members, consisting of either fabric, cord, and/or metal of a hose (sometimes intended as the non-rubber elements of a hose).
Reinforcing agent: an ingredient (not basic to the vulcanization process) used in a rubber compound to increase its resistance to mechanical forces.
Resin: a compounding material, solid or liquid in form, used to modify the processing and/or vulcanized characteristics of a compound.
Retarder: a compounding ingredient used to reduce the tendency of a rubber compound to vulcanize prematurely.
Reusable coupling: reusable fitting.
Reusable fitting: the type of fitting which, by design, may be removed and reused.
Reversion: the softening of vulcanized rubber when it is exposed to an elevated temperature; a deterioration in physical properties; (extreme reversion may result in tackiness.).
Rise test: a determination of the distance a fire hose, under a specified internal pressure, lifts from the surface on which is rests.
Roll ratio: the ratio of the surface speeds of two adjacent mill or calender rolls.
Rubber: a material, elastomer based, that is capable of recovering from large deformations quite quickly.
Rubber cement: generally adhesive cement, rubber based.
Safety factor: design factor.
Sampling: a process of selecting a portion of a quantity of a hose for testing or inspection, selected without regard to quality.
Scorch: premature vulcanization of a rubber compound.
Screw-together reusable fitting: a type of hose fitting whose socket and nipple are threaded together in combination with the hose.
Seam: a line formed by the joining of the edges of a material to form a single ply or layer.
Seaming strip: a strip of material laid over a seam to act as a binder.
Self cure: vulcanization without the application of heat.
Semi-cure: a preliminary but incomplete cure applied to a tube or hose in the process of manufacture to cause the tube or hose to acquire a degree of stiffness or to maintain some desired shape, service pressure.
Service test: or field test, a test in which the product is used under actual service conditions.
Set: the amount of strain remaining after complete release of a load producing a deformation.
Shank: that portion of a fitting, which is inserted into the bore of a hose.
Shear modules: the ratio of the shear stress to the resulting shear strain (the latter expressed as a fraction of the original thickness of the rubber measure, at right angles to the force); shear modules may be either static or dynamic.
Shelf storage life: the period of time prior to use during which a product retains its intended performance capability.
Shell: sometimes as alternative to the term ferrule.
Shock load: a stress created by a sudden force.
Simulated service test: test of field simulation.
Sink: a collapsed blister or bubble leaving a depression in a product.
Skim coat: a layer of rubber material laid on a fabric but not forced into the eave.
Skimmed fabric: a fabric coated with rubber on a calendar; the skim coat may or may not be applied over a friction coat.
Skive: the removal of a short length of cover to permit the attachment of a fitting directly over the hose reinforcement.
Slip-on nut: method to block the nut on the fitting by means of a plastic slip.
Smooth bore hose: a wire reinforced hose in which the wire is not exposed on the inner surface of the tube.
Smooth cover: a cover having an even and uninterrupted smooth surface.
Socket: the external member or portion of a hose fitting, commonly used in describing screw-together reusable fittings.
Soft end: a hose end in which the rigid reinforcement of the body, usually wire, is omitted.
Spacing: the space between adjacent turns of helically wound wire.
Specification: a document setting pertinent details of a product, such as performance, chemical composition, physical properties and dimensions, prepared for use in, or to form the basis for, an agreement between negotiating parties.
Specific gravity: the ratio of the weight of a given substance to the weight of an equal volume of water at a specified temperature.
Specimen: an appropriately shaped and prepared sample, ready for use in a test procedure.
Spider mark: a cleavage or weak spot caused by the failure of a compound to reunite after passing a spoke of the spider of an extrusion machine.
Spiral: a method of applying reinforcement in which there is no interlacing between individual strands of the reinforcement.
Spiral lay: the manner in which a spiral reinforcement is applied with respect to angularity and lead or pitch as in a hose or cylindrical article.
Splice: a joint or junction made by lapping or butting, and held together through vulcanization or mechanical means.
Spread: a thin coat of material in solvent form applied on a fabric surface by means of knife, bar or doctor blade.
Spread fabric: a fabric the surface of which is coated with a rubber solution and dried.
Spring guard: a steel or plastic helically wound protection applied externally to the hose to protect from abrasion or make bunches of hoses.
Standard: a document or an object for physical comparison, for defining product characteristics, products or processes, prepared by a consensus of a properly constituted group of those substantially affected and having the qualifications to prepare the standard for use.
Staple: a steel fork used for special fittings connection.
Static bonding: use of a grounded conductive material to eliminate static electrical charges.
Static conductive: having the capability of furnishing a path for a flow of static electricity.
Static wire: a wire incorporated in a hose to conduct static electricity.
Stock: an uncured rubber compound of a definite composition from which a given article is manufactured.
Straight end: a hose end with an inside diameter the same as that of the main body of the hose.
Straight wrap: in a curing process, a wrap of lightweight fabric in which the warp threads of the fabric are parallel to the axis of the hose.
Stress relaxation: the decrease in stress after a given time at constant strain.
Stress-strain: the relationship of force and deformation of a unit area of a body during compression, extension or shear.
Stretch: an increase in dimension, an elongation.
Strike through: in coated or frictioned fabric, a penetration of rubber compound through the fabric; in woven fire hose, the penetration of the rubber backing through the jacket.
Strip test: in fabric testing, tensile strength test made on a strip of fabric raveled down to a specified number of threads or width of fabric.
Sulphur free: the sulphur in a rubber compound extractable by sodium sulphite after the normal vulcanization process.
Sulphur total: all the sulphur present in a rubber compound, including inorganic sulphides and sulphates.
Sun checking: the surface cracks, checks, or crazing caused by exposure to direct or indirect sunlight.
Surge: a rapid and transient rise in pressure.
Swaging: the act of forming a hose fitting by passing it into a die, generally split, which is sized to yield the desired finished fitting diameter.
Swelling: an increase in volume or linear dimension of a material specimen immersed in liquid or exposed to a vapor.
Tack: the ability to adhere to itself.
Tack rubber: a property of a rubber and rubber compounds that causes two layers of compounds that have been pressed together to adhere firmly at the area of contact.
Tear resistance: the property of a rubber tube or cover of a hose to resist tearing forces.
Teeth: the tension filaments which appear between two adhering plies of rubber as they are pulled apart.
Tensile strength: the maximum tensile stress applied while stretching a specimen to rupture.
Tensile stress: a stress applied to stretch a test piece (specimen).
Termination end: the end part of the fitting, connection and sealing type of a fitting.
Test pressure: pressure used to perform a test (e.g. impulse test, proof test).
Tex: a yarn size system defined as the weight in grams of 1000 meters of yarn.
Thermoplastics: range of resins being easily softened under heat.
Thin cover: a cover, the thickness of which is less than specified; a wire braid hydraulic hose specifically made with a thin cover to eliminate the need for skiving when attaching couplings.
Thin tube: a lining the thickness of which is less than specified (compact).
Thrust wire nut: method of mechanical connection of the nut on the fitting by means of a circular wire.
Tight braid: an unevenness in a braid reinforcement caused by one or more ends of the reinforcement being applied at a greater tension than the remaining ends; a localized necking down of the braided reinforcement caused by a stop in the braiding operation.
Tolerance: the upper and lower limits between which a dimension must be held; the total range of variation, usually bilateral, permitted for a size, position or other required quantity.
Trapped air: air trapped during cure, which usually causes a loose ply or cover, a surface mark, depression or void.
Tube: the innermost continuous all-rubber or plastic element of a hose.
Tubing: a non-reinforced, flexible, homogeneous conduit, generally of circular cross-section.
Twist: the turns about the axis, length of hose, of a fiber, etc; twist is usually expressed as turns per length unit.
Ultimate strength: tensile strength.
Undercure: a less than optimal state of vulcanization, which may be evidenced by tackiness or inferior physical properties.
Viscosity: the resistance of a material to flow under stress.
Void: the absence of material or an area devoid of materials where not intended.
Volume change: a change in linear dimensions of a specimen immersed in a liquid or exposed to a vapour.
Vulcanization: an irreversible process during which a rubber compound, through a change in its chemical structure (e.g. cross-linking), becomes less plastic and more resistant to swelling by organic liquids, and which confers, improves or extends elastic properties over a great range of temperature.
Volumetric expansion: the volume increase of hose when subjected to internal pressure. It is generally reported in cubic centimeters per unit length of hose.
Warp: the lengthwise yarns in a woven fabric or in a woven hose jacket; also the deviation from a straight line of a hose while subjected to internal pressure.
Water resistant: having the ability to withstand the deteriorating effect of water.
Wavy tube: a tube or lining with an inner surface having surface ripples formed by the pattern of the reinforcement.
Weathering: the surface deterioration of a hose cover during outdoor exposure, as shown by cracking or crazing.
Weft: a term used for filling.
Weftless cord fabric: a cord fabric either without filling yarns or with a few small filling yarns widely spaced.
Wire braid: see braid.
Wire loop: in braided hose, a loop in the wire reinforcement caused by uneven tensions during bobbin winding or braiding.
Wire reinforced: a hose containing wires to give added strength, increased dimensional stability, or crush resistance.
Wire throw-out: in braided hose, a broken end or ends in the wire reinforcement protruding from the surface of the braid.
Wire wound: having a single wire or a plurality of wires spiraled in one or more layers as a protective or reinforcing member.
Wire woven: woven with the wire reinforcement applied helically by means of a circular loom.
Working pressure: the maximum pressure to which a hose will be subjected, including the momentary surges in pressure which can occur an during service; frequently abbreviated as WP.
Woven fabric: a flat structure composed of two series of interlacing yarns or filaments, one parallel to the axis of the fabric and the other transverse.
WP: the abbreviation for working pressure.
Wrapped cure: a vulcanizing process using a tensioned wrapper (usually of fabric) to apply external pressure.
Wrapper marks: the impressions left on the surface of a hose by a material used during vulcanization.
Yarn: a generic term for continuous strands of textile fibers or filaments in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric.
Zinc-plating: traditional external treatment for corrosion resistance of steel components, applied to
couplings, adaptors, etc. with electrochemical methods.