Carefully inspect all hydraulic hose and fittings at regular intervals to make sure airworthiness. Investigate any proof fluid loss or leaks. Check metal tubes for leaks, loose anchorage, scratches, kinks, or other damage. Inspect fittings and connections for leakage, looseness, cracks, burrs, or other damage. Replace or repair defective elements. Make sure the hoses do not chafe against one another and are correctly secured and clamped.
a. Replacement of Metal tube. When inspection shows hydraulic hose to be damaged or defective replace the whole line or, if the damaged section is localized, a repair section might be inserted. In replacing aircraft hose, always use tubing of the exact same size and material as the first line. Use the old tubing as a template when bending the new tube, unless it's too greatly damaged, by which case a template could be produced from soft iron wire. Soft aluminum tubing (1100, 3003, or 5052) under half-inch outside diameter might be bent by hand. For all other tubing use an acceptable hand or power tube-bending tool. Bend tubing carefully in order to avoid excessive flattening, kinking, or wrinkling. A tiny amount of flattening in bends is acceptable, but do not exceed 75 percent of the first outside diameter. Excessive flattening can cause fatigue failure of the hydraulic tube. When installing the replacement tubing line it down correctly with the mating part such that it is not forced into alignment by tightening of the coupling nuts.
b. Hose couplings and Tube Connections. Many tube connections are created using flared tube ends with
standard 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 thoroughly clean. The tubing is then flared utilising the correct 37-degree aviation flare forming tool for the size of tubing and type of fitting. A dual flare is utilized on soft aluminum tubing 3/8-inch outside diameter and under, and an individual flare on all other tubing. For making the connections, use hydraulic fluid as a lubricant and then tighten. Overtightening will damage the tube or fitting, which can result in a failure. Under-tightening may cause leakage that could result in a system failure.
CAUTION: Mistaken utilization of 45-degree automotive flare forming tools may lead to improper tubing flare shape and angle; causing misfit, stress and strain, and probable system failure.
c. Repair of aircraft hydraulic Metal Tube Lines. Minor dents and scratches in tubing might be repaired. Scratches or nicks not deeper than 10 percent of the wall thickness in aluminum alloy tubing, that aren't in the heel of a bend, might be repaired by burnishing with hand tools. Replace lines with severe die marks, seams, or splits in the tube. Any crack or deformity in a flare is unacceptable and reason for rejection. A reduction less than 20 percent of the tube diameter is not objectionable unless it's in the heel of a bend. A severely-damaged line should be replaced; however, it may be repaired by cutting out the damaged section and inserting a pipe portion of the exact same size and material. Flare both ends of the undamaged and replacement tube sections and make the text by utilizing standard unions, sleeves, and tube nuts.If the damaged portion is short enough, omit the insert tube and repair by utilizing one union and two sets of connection hose fittings.
d.Replacement of Flexible Hose. When replacement of flexible hose is important, utilize the same type, size, part number, and length of hose as the line to be replaced. Check TSO requirements. If the replacement of a line with a swaged-end type fitting is important, obtain new hydraulic hose assemblies of the correct size and composition. Certain synthetic oils require a specially compounded synthetic rubber hose, which can be compatible. Make reference to the aircraft manufacturer's service information for the correct part number for the replacement hose. If the fittings on each end are of the correct type or sleeve type, a replacement might be fabricated. Before cutting new flexible wire braided hose to the proper size, tape the hose tightly with masking tape and cut in the middle of the masking tape to prevent fraying. The use of a mandrel will prevent cutting the interior of the hose when inserting the fittings. Install hose assemblies without twisting. A line shouldn't be stretched tight between two fittings as this can lead to overstressing and eventual failure. The length of hose should be sufficient to provide about 5 to 8 percent slack. Avoid tight bends in flex lines as they might lead to failure. Never exceed the minimum bend radii.
(1) Teflon hose is found in many aircraft systems because it has superior qualities for several applications. Teflon is compounded from tetrafluoroethylene resin which can be unaffected by fluids normally found in aircraft. It comes with an operating selection of -65°F to 450 °F. For these reasons, Teflon hose is found in hydraulic and engine lubricating systems where temperatures and pressures preclude the usage of rubber hose. Although Teflon hose has excellent performance qualities, it even offers peculiar characteristics that need extra care in handling. hydraulic torque wrench for sale It will assume a lasting set when exposed to high pressure or temperature. Do not try to straighten a line that has been around service. Any excessive bending or twisting may cause kinking or weakening of the tubing wall. Replace any hose that shows signs of leakage, abrasion, or kinking. Any hose suspected of kinking might be checked with a metal ball of proper size.The ball will not pass through if the hose is distorted beyond limits.
(2) If the hose fittings are of the reusable type, a replacement hose might be fabricated. When a hose assembly is removed, the ends should be tied, so that the preformed shape is going to be maintained.
(3) All flexible hose installations should be supported at least every 24 inches. Closer supports are preferred. They must be carefully routed and securely clamped in order to avoid abrasion, kinking, or excessive flexing. Excessive flexing may cause weakening of the hose or loosening at the fittings.
Troubleshooting Hydraulic Machines
Hydraulic machines are found in varied industrial activities today. Undoubtedly manufacturers of hydraulic machinery are taking keen curiosity about producing the very best machines, which are well designed, well manufactured and can provide a reliable performance for most years. Any user who uses hydraulic equipments would always like to really have a trouble free system. But to really have a hydraulic machine without giving you any trouble sounds too good to be true. Even when the oil or filter is changed regularly, as well as if the preventive maintenance program is followed, the machine is going to stop at some point of time. This becomes much more dangerous when it happens in the midst of a production process.
What do you do under this circumstance? It is better to be equipped for such a situation so that the work is not stopped for a long amount of time. This is what is referred as troubleshooting your hydraulic machine. Presenting below some easy methods to hydraulic troubleshooting.
To start with, learn hydraulics, find out how they work since this is the better way you are able to handle a problem. Understand how all the equipment work, how the device handles pressure, flow and direction, how they're linked to each other. Study the manufacturer's catalog. Gather as much information regarding breakdowns, lists of components, pressure settings, testing points, how many actuators, pumps, valves are found in the system.
Do not await the full time when the machine is totally not working. Actually some precautions can be used even if the machine is in an operating condition. All hydraulic machines operators must follow a
When actually the hydraulic machine stops working, do these:
- Find out under what circumstances or what caused the machine to are amiss?
- Was it at the start of the cycle?
- Keep in touch with the machine operator.
- Try to obtain as much information as possible.
- Check the hydraulic schematics. Find out the road from the pump to the actuator. Which actuator or valve was working when the machine stopped?
- Find out whether you will find any problems in some components like pumps, some directional valves, some flow controls, relief valves.
- Perform the flow and pressure test adding yet another element such as the relief valve following the pump, and so on until you're able to the cylinder.
As soon as you gather information, its time for you to act. In a nutshell, hydraulic trouble shooting is not a very easy task, but with proper understanding of hydraulics, with full machine information and equipment, troubleshooting becomes easier and faster.
All About Hydraulic Check Valves
Hydraulic check valves are the most trusted valves that enable fluid to flow in one single direction in a hydraulic system and prevent reversal of liquid flow. That's why the name the "check valve" ;.Put simply, this product is installed in a pipe so that the water doesn't flow backwards in the pipe. There is a mechanism in the pipe which moves in line with the flow of the water towards the valve, and when required, the mechanism plugs up the valve opening so that there surely is no flow of water backwards.
In a hydraulic check valve, you will find two openings. The inlet through that the hydraulic fluid enters and an outlet through that the fluid goes out. A good thing is which they operate automatically. They work in relation with hydraulic pumps, motors and cylinders. The valves control the flow and pressure of the fluid so that there surely is proper functioning of the equipment. best hydraulic torque wrench
You will find different designs available in hydraulic valves like ball, plunger, swinging disc, and poppet. With regards to the application area, the size and shape varies. These check valves are found in industrial applications that need hydraulic pumps, like in automotive braking systems, vehicles, construction tools, including city water and sewer systems. They're found in systems the place where a backup of fluid could create problems on a sizable scale.
Hydraulic valves are used for different reasons such as follows:
- The vital role they play is which they prevent flooding when there is extreme back flow of water running through the pipes.
- They avoid the damage of the machine from water flowing the wrong direction.
- When the machine is put off, the valve helps in avoiding the fluid from flowing back in the wrong direction. In return, they save power and also protect the pipes from water damage.
- They allow liquid flow in one single direction.
- They control fluid pressure.
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