Aircraft Hydraulic Hose And Hydraulic Hose Fittings
Fastidiously inspect all hydraulic hose and fittings at regular intervals to ensure airworthiness. Examine any proof of fluid loss or leaks. Examine metal tubes for leaks, free anchorage, scratches, kinks, or different injury. Examine fittings and connections for leakage, looseness, cracks, burrs, or other damage. Change or repair defective elements. Ensure that the hoses do not chafe in opposition to one another and are accurately secured and clamped.
a. Substitute of Steel tube. When inspection shows hydraulic hose to be broken or defective substitute the whole line or, if the damaged section is localized, a repair part could also be inserted. In changing aircraft hose, always use tubing of the same dimension and material as the unique line. Use the outdated tubing as a template when bending the brand new tube, unless it is simply too tremendously damaged, during which case a template might be made from smooth iron wire. Gentle aluminum tubing (1100, 3003, or 5052) beneath half-inch outside diameter could also be bent by hand. For all different tubing use an appropriate hand or power tube-bending device. Bend tubing fastidiously to keep away from excessive flattening, kinking, or wrinkling. A small quantity of flattening in bends is acceptable, but don't exceed seventy five p.c of the original exterior diameter. Extreme flattening will trigger fatigue failure of the hydraulic tube. When installing the substitute tubing line it up correctly with the mating part in order that it isn't forced into alignment by tightening of the coupling nuts.
b. Hose couplings and Tube Connections. Many tube connections are made utilizing flared tube ends with normal connection fittings: AN-818 (MS 20818) nut and AN-819 (MS 20819) sleeve. In forming flares, cut the tube ends square, file smooth, remove all burrs and sharp edges, and completely clear. The tubing is then flared utilizing the correct 37-degree aviation flare forming instrument for the dimensions of tubing and sort of fitting. A double flare is used on comfortable aluminum tubing 3/8-inch exterior diameter and under, and a single flare on all different tubing. In making the connections, use hydraulic fluid as a lubricant after which tighten. Overtightening will harm the tube or fitting, which can trigger a failure. Below-tightening could trigger leakage which might end in a system failure.
Warning: Mistaken use of 45-degree automotive flare forming tools could end in improper tubing flare shape and angle; causing misfit, stress and strain, and probable system failure.
c. Restore of aircraft hydraulic Metal Tube Lines. Minor dents and scratches in tubing could also be repaired. Scratches or nicks not deeper than 10 % of the wall thickness in aluminum alloy tubing, that are not within the heel of a bend, could also be repaired by burnishing with hand tools. Replace lines with severe die marks, seams, or splits within the tube. Any crack or deformity in a flare is unacceptable and trigger for rejection. A dent lower than 20 p.c of the tube diameter will not be objectionable unless it's in the heel of a bend. A severely-broken line should be replaced; nevertheless, it could also be repaired by reducing out the broken section and inserting a tube part of the identical size and materials. Flare both ends of the undamaged and alternative tube sections and make the connection by utilizing normal unions, sleeves, and tube nuts.If the broken portion is short enough, omit the insert tube and restore by using one union and two sets of connection hose fittings.
d.Substitute of Versatile Hose. When replacement of flexible hose is important, use the same sort, dimension, part number, and length of hose as the line to be replaced. Verify TSO requirements. If the alternative of a hose with a swaged-finish kind fitting is critical, obtain new hydraulic hose assemblies of the correct dimension and composition. Certain artificial oils require a specifically compounded synthetic rubber hose, which is compatible. Check with the aircraft manufacturer's service information for the right part quantity for the substitute hose. If the fittings on every end are of the proper kind or sleeve sort, a substitute may be fabricated. Earlier than slicing new flexible wire braided hose to the correct dimension, tape the hose tightly with masking tape and cut in the center of the masking tape to stop fraying. The usage of a mandrel will forestall slicing the inside of the hose when inserting the fittings. Install hose assemblies with out twisting. hydraulic quick coupler be stretched tight between two fittings as this can lead to overstressing and eventual failure. The size of hose ought to be adequate to supply about 5 to 8 percent slack. Avoid tight bends in flex traces as they could result in failure. By no means exceed the minimal bend radii.
(1) Teflon hose is used in many aircraft techniques because it has superior qualities for certain applications. Teflon is compounded from tetrafluoroethylene resin which is unaffected by fluids normally used in aircraft. It has an working range of -65°F to 450 °F. For these reasons, Teflon hose is used in hydraulic and engine lubricating systems the place temperatures and pressures preclude using rubber hose. Although Teflon hose has wonderful performance qualities, it additionally has peculiar characteristics that require additional care in dealing with. It tends to assume a permanent set when uncovered to excessive stress or temperature. Don't try and straighten a hose that has been in service. Any excessive bending or twisting may cause kinking or weakening of the tubing wall. Exchange any hose that reveals signs of leakage, abrasion, or kinking. Any hose suspected of kinking may be checked with a steel ball of correct measurement.The ball won't cross by if the hose is distorted beyond limits.
(2) If the hose fittings are of the reusable sort, a alternative hose could also be fabricated. When a hose meeting is removed, the ends needs to be tied, so that the preformed form might be maintained.
(3) All flexible hose installations ought to be supported a minimum of every 24 inches. Closer supports are most well-liked. They needs to be rigorously routed and securely clamped to avoid abrasion, kinking, or excessive flexing. Extreme flexing might trigger weakening of the hose or loosening at the fittings.
a. Substitute of Steel tube. When inspection shows hydraulic hose to be broken or defective substitute the whole line or, if the damaged section is localized, a repair part could also be inserted. In changing aircraft hose, always use tubing of the same dimension and material as the unique line. Use the outdated tubing as a template when bending the brand new tube, unless it is simply too tremendously damaged, during which case a template might be made from smooth iron wire. Gentle aluminum tubing (1100, 3003, or 5052) beneath half-inch outside diameter could also be bent by hand. For all different tubing use an appropriate hand or power tube-bending device. Bend tubing fastidiously to keep away from excessive flattening, kinking, or wrinkling. A small quantity of flattening in bends is acceptable, but don't exceed seventy five p.c of the original exterior diameter. Extreme flattening will trigger fatigue failure of the hydraulic tube. When installing the substitute tubing line it up correctly with the mating part in order that it isn't forced into alignment by tightening of the coupling nuts.
b. Hose couplings and Tube Connections. Many tube connections are made utilizing flared tube ends with normal connection fittings: AN-818 (MS 20818) nut and AN-819 (MS 20819) sleeve. In forming flares, cut the tube ends square, file smooth, remove all burrs and sharp edges, and completely clear. The tubing is then flared utilizing the correct 37-degree aviation flare forming instrument for the dimensions of tubing and sort of fitting. A double flare is used on comfortable aluminum tubing 3/8-inch exterior diameter and under, and a single flare on all different tubing. In making the connections, use hydraulic fluid as a lubricant after which tighten. Overtightening will harm the tube or fitting, which can trigger a failure. Below-tightening could trigger leakage which might end in a system failure.
Warning: Mistaken use of 45-degree automotive flare forming tools could end in improper tubing flare shape and angle; causing misfit, stress and strain, and probable system failure.
c. Restore of aircraft hydraulic Metal Tube Lines. Minor dents and scratches in tubing could also be repaired. Scratches or nicks not deeper than 10 % of the wall thickness in aluminum alloy tubing, that are not within the heel of a bend, could also be repaired by burnishing with hand tools. Replace lines with severe die marks, seams, or splits within the tube. Any crack or deformity in a flare is unacceptable and trigger for rejection. A dent lower than 20 p.c of the tube diameter will not be objectionable unless it's in the heel of a bend. A severely-broken line should be replaced; nevertheless, it could also be repaired by reducing out the broken section and inserting a tube part of the identical size and materials. Flare both ends of the undamaged and alternative tube sections and make the connection by utilizing normal unions, sleeves, and tube nuts.If the broken portion is short enough, omit the insert tube and restore by using one union and two sets of connection hose fittings.
d.Substitute of Versatile Hose. When replacement of flexible hose is important, use the same sort, dimension, part number, and length of hose as the line to be replaced. Verify TSO requirements. If the alternative of a hose with a swaged-finish kind fitting is critical, obtain new hydraulic hose assemblies of the correct dimension and composition. Certain artificial oils require a specifically compounded synthetic rubber hose, which is compatible. Check with the aircraft manufacturer's service information for the right part quantity for the substitute hose. If the fittings on every end are of the proper kind or sleeve sort, a substitute may be fabricated. Earlier than slicing new flexible wire braided hose to the correct dimension, tape the hose tightly with masking tape and cut in the center of the masking tape to stop fraying. The usage of a mandrel will forestall slicing the inside of the hose when inserting the fittings. Install hose assemblies with out twisting. hydraulic quick coupler be stretched tight between two fittings as this can lead to overstressing and eventual failure. The size of hose ought to be adequate to supply about 5 to 8 percent slack. Avoid tight bends in flex traces as they could result in failure. By no means exceed the minimal bend radii.
(1) Teflon hose is used in many aircraft techniques because it has superior qualities for certain applications. Teflon is compounded from tetrafluoroethylene resin which is unaffected by fluids normally used in aircraft. It has an working range of -65°F to 450 °F. For these reasons, Teflon hose is used in hydraulic and engine lubricating systems the place temperatures and pressures preclude using rubber hose. Although Teflon hose has wonderful performance qualities, it additionally has peculiar characteristics that require additional care in dealing with. It tends to assume a permanent set when uncovered to excessive stress or temperature. Don't try and straighten a hose that has been in service. Any excessive bending or twisting may cause kinking or weakening of the tubing wall. Exchange any hose that reveals signs of leakage, abrasion, or kinking. Any hose suspected of kinking may be checked with a steel ball of correct measurement.The ball won't cross by if the hose is distorted beyond limits.
(2) If the hose fittings are of the reusable sort, a alternative hose could also be fabricated. When a hose meeting is removed, the ends needs to be tied, so that the preformed form might be maintained.
(3) All flexible hose installations ought to be supported a minimum of every 24 inches. Closer supports are most well-liked. They needs to be rigorously routed and securely clamped to avoid abrasion, kinking, or excessive flexing. Extreme flexing might trigger weakening of the hose or loosening at the fittings.
Public Last updated: 2021-05-17 09:17:40 PM