Pipes And Hoses
Pipes and Hoses
Pipes and hoses can be called upon to carry a wide variety of different fluids within an aircraft, including fuel, hydraulic and engine oils, de-icing fluids, pitot and static air.
The pressure within these pipes can vary from ambient to 300 M Pa (300 bar or 4000 psi). All pipes and hoses must be manufactured, installed and connected so that no leaks occur in service, because a leak in a very low-pressure pitot air tube can be just as dangerous as a leak in an extremely high-pressure hydraulic line.
Generally, rigid pipelines are made from stainless steel, Tungum (Trade name for a high-tensile, copper alloy) and aluminium alloy. Replacement pipelines are usually supplied by the manufacturer, ready for installation, with the pipe bent to the correct curvature and the pipe ends flared and provided with the appropriate end fittings.
In certain circumstances, it may be permissible to manufacture new pipelines from lengths of pipe. A new pipeline will be made, by cutting the basic pipe to the correct length, attaching the correct couplings and expanding the ends by the use of a flaring tool.
Requests for the basic pipe material will require details of the:
- Metal specification (DTD, BS, AN etc.)
- Outside diameter (OD)
- Gauge of the wall thickness (SWG)
- Length of pipe required.
Flexible hoses are obtained from the aircraft manufacturer using the aircraft’s Illustrated Parts Catalogue (IPC). In certain circumstances, it is possible that a replacement hose can be manufactured in a workshop or hose bay. Approval to manufacture the replacement hose must be sought from the aircraft’s manufacturer.