Deliberately assess all pressure driven hose and fittings at standard interims to guarantee airworthiness. Research any proof of liquid misfortune or holes. Check metal tubes for releases, free jetty, scratches, wrinkles, or other harm. Assess fittings and associations for spillage, detachment, breaks, burrs, or other harm. Supplant or repair blemished components. Ensure the hoses don’t scrape against each other and are accurately secured and cinched.
a. Substitution of Metal tube. At the point when examination demonstrates water driven hose to be harmed or imperfect supplant the whole line or, if the harmed area is restricted, a repair segment might be embedded. In supplanting flying machine hose, dependably utilize tubing of the same size and material as the first line. Utilize the old tubing as a format when bowing the new tube, unless it is too significantly harmed, in which case a layout can be produced using delicate iron wire. Delicate aluminum tubing (1100, 3003, or 5052) under half-creep outside measurement might be twisted by hand. For all other tubing utilize a satisfactory hand or power tube-bowing apparatus. Twist tubing painstakingly to maintain a strategic distance from intemperate straightening, crimping, or wrinkling. A little measure of straightening in twists is adequate, yet don’t surpass 75 percent of the first outside distance across. Inordinate straightening will bring about weakness disappointment of the water driven tube. At the point when introducing the substitution tubing line it up accurately with the mating part so it is not constrained into arrangement by fixing of the coupling nuts.
b. Hose couplings and Tube Connections. Numerous tube associations are made utilizing flared tube closes with
standard association fittings: A 818 (MS 20818) nut and A 819 (MS 20819) sleeve. In shaping flares, cut the tube closes square, record smooth, expel all burrs and sharp edges, and completely spotless. The tubing is then flared utilizing the right 37-degree aeronautics flare framing instrument for the extent of tubing and sort of fitting. A twofold flare is utilized on delicate aluminum tubing 3/8-inch outside distance across and under, and a solitary flare on all other tubing. In making the associations, use water driven liquid as a grease and after that fix. Overtightening will harm the tube or fitting, which may bring about a disappointment. Under-fixing may bring about spillage which could bring about a framework disappointment.
Alert: Mistaken utilization of 45-degree car flare framing apparatuses may bring about dishonorable tubing flare shape and edge; creating loner, anxiety, and plausible framework disappointment.
c. Repair of airplane water driven Metal Tube Lines. Minor gouges and scratches in tubing might be repaired. Scratches or scratches not further than 10 percent of the divider thickness in aluminum compound tubing, that are not in the heel of a twist, might be repaired by polishing with hand apparatuses. Supplant lines with serious kick the bucket checks, creases, or parts in the tube. Any break or distortion in a flare is unsatisfactory and reason for dismissal. An imprint under 20 percent of the tube breadth is not frightful unless it is in the heel of a twist. An extremely harmed line ought to be supplanted; in any case, it might be repaired by removing the harmed segment and embeddings a tube area of the same size and material. Flare both finishes of the undamaged and substitution tube segments and make the association by utilizing standard unions, sleeves, and tube nuts.If the harmed part is sufficiently short, preclude the addition tube and repair by utilizing one union and two arrangements of Automotive hose fittings.