2.........…..............…........…........…........…........…........…........1
NOTE: CONSULT BOEING BEFORE USING ALTERNATE TUBE MATERIAL/WALL THICKNESS
____ COMBINATIONS FOR 3000 PSI HYDRAULIC SYSTEM APPLICATIONS
TASK 20-11-05-308-286
2. Tube Repair
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A. General
(1) Use Hydraulic System Design Pressure/IN PSI/ as shown in Table 2 during repairs.
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~............................................................................... | TABLE 2 | | HYDRAULIC SYSTEM DESIGN PRESSURES | ................................................................................. | COMPONENT | Maximum Working | Proof | Burst | | | Pressure | Pressure | Pressure | | | psi | psi | psi | ................................................................................. |Pressure lines (including | | | | |hoses and fittings) and | | | | |units with air under full | | | | |system pressure (such as | | | | |accumulators). | 3000 | 6000 | 12000 | ................................................................................. |Return and case drain lines,| 600 | 900 | 1500 | |fittings and units | | | | ................................................................................. |Return line hoses | 600 | 1500 | 3000 | ................................................................................. |Pump Supply reservoirs, | 65 | 100 | 200 | |units, lines and fittings | | | | ................................................................................. |Airbleed Line (Upstream of | | | | |regulator) | 250 | 500 | 1000 | ................................................................................. |Drains and vents open to | | | | |atmosphere | 15 | 50 | 75 | 2............................…...................…...............…..............1
CAUTION:_______DO NOT REPAIR COIL TUBES. NORMAL MOVEMENT OF COIL MAY BE RESTRICTED BY A REPAIR.
(2)
You can repair tubes if you obey the permitted repair limits. When it is possible do the following:
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replace the damaged tube
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replace the damaged part with a tube splice
-repair the damaged tube with a fitting (if the damaged are is sufficiently small).
-completely remove all corrosion and treat affected surface area as described in the Corrosion Prevention Manual.
(3)
When you remove, install, or do work with hydraulic tube assemblies, obey the guidelines that follow:
(a) When you remove tubes, you must make sure the tubes and port fitings have tags that identify the correct connection location.
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(b) Do not move or change the tube bends. If you move or change the bend in the tube, these bad effects can occur: 1) If you move or change a bend in the tube, it can become possible that the tube will align with the incorrect port. If this occurs, incorrect reconnection or cross-correction of the tubes can become possible.
2) If you move or change the bend in the tube, it can be possible that the tube will have too much stress when it is connected. Stress can cause cracks in the tubes.
(c)
If you must bend the tube assemblies to fit the installation, do not bend more than permitted by the ovality limits in Fig. 801. We recommend that you use a bend block or tool equivalent to the Parker G-824 hand bender. Make sure the bend block supports the tube bend beyond the neutral axis of the bend, as shown in Fig. 801, and that bend-ovality allowables are not exceeded.
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