1. Title of the invention
Design and Development of Universal Oxygen Test Rig to Carry out Pressure and Flow Tests as per OEM stipulated parameters.
2. Field of invention
This invention is related to the manufacture, testing and quality assurance of Aircraft Oxygen System.
3. Use of invention
This invention is used to charge/fill Aircraft Oxygen Cylinders, test the reduced pressure, pressure drop and Flow characteristics of Oxygen LRUs for various Aircraft Oxygen System.
4. Prior art
There was no previous test Rig available for the testing of the subject LRUs.
5. Draw backs of prior art
Not applicable, as this is a new Test Rig developed for the first time.
6. Comparison between prior art and present invention
Not applicable, as this is a new Test Rig developed for the first time. '
7. Aim of the invention
Aim of the invention was to develop a simple and effective Test Rig with .available Resources, to test the subject LRUs of Aircraft Oxygen System.
8. Summary of the present invention
The oxygen system provides the pilot with breathing oxygen at high altitudes and all flight conditions. It Consists of Storage Cylinders, Pressure Reducing Valves, Emergency Oxygen Set, and Hoses. These Units needs to be tested in Lab before fitment to Aircraft. The test Rig is developed to test these units in Lab.

9. Brief description of drawings
FIG. 1: Schematic Diagram of Test Rig
10. Statement of invention
This invented Test Rig is useful to check the serviceability of subject LRUs in Lab before fitment on the Aircraft.
11. Detailed description of invention
a. The Test Rig is designed considering the Charging requirement of High Pressure cylinders and various testing requirements of Pressure reducing valve, pressure Reducer-heads of cylinders, Emergency Oxygen Set and Hoses.
b.. The Basic functions of the Rig include Charging of Cylinders for leak tests,
reduced pressure tests, Flow tests, and pressure drop tests. C. The test bench frame is made out of aluminum sheets cut according to the required dimension. The front and back panel is also made out of aluminum sheets. The left side of. frame has a hole for pressure inlet line. The Test rig consists of the following parts.
d. An input gauge which shows the pressure of the source. [Gl]
e. A pressure regulator which provides with the necessary pressure required for
testing. [R]
f. An output gauge which shows the output of the regulator [G2],
g. An output gauge which shows low range output pressure [G3].
h. An outlet point from regulator [Al].

i. A bleed valve which allows bleeding of high pressure line [£].
j. A pressure gauge of lower range [G3] which is isolated by an On-Off valve [VI].
k. A pressure gauge G4 which reads the output of the unit through an adaptor [A?] and on-off valve [1/2].
I. An adaptor [A3] connected to a pressure gauge [G5] to read the output of the unit while drawing a flow as specified in test procedures.
m. A Flowmeter of lower range [Fl] through an On-Off valve [V3] which reads the flow from the unit.
n. A Flowmeter of higher range [F2] through an On-Off valve [1/4] which reads flow drawn from the unit,
o. The functions of the Test Rigs are as mentioned below.
p. The input from the pressure source [S] is connected through a high pressure copper line to a 0 to 6000 psi pressure gauge [Gl] and a pressure regulator [R].
q. From the pressure regulator a high pressure copper line is connected to another 0 to 6000 psi pressure gauge [G2]. This is the source of pressure to the units under test.
r. A tapping is taken from this line and through an On-Off valve [VI] it is connected to a 0 to 300 psi pressure gauge [G3] for reading low pressure.

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s. The output of the regulator is also connected to an adaptor [Al] fixed on the panel.
t. Between the regulator and adaptor a bleed valve [6] is provided so that the pressure in the high pressure line can be released after charging the unit..
u. A 0 to 3000 psi gauge [G4] is connected to the adaptor [A2] through the on off valve [1/2]. This is to read the output of LRUs.
v. The adaptor [A3] fitted 'on the panel is connected through a 0 to 160 psi pressure gauge [G5] by means of a high pressure hose.
w. A taping is taken from this line and connected to the Flowmeters [Fl] and [F2]. The Flowmeters are isolated by means of on off valves [1/3] and [V4].
x. Each flow meters can be individually brought into the circuit by means of the on off valves. The drop in pressure while drawing the flow can be obtained from the pressure gauge since they are interconnected.

Claims
We claim
1. Design of the Pressure and flow circuit in the test bench to maximize the testing range
which includes charging, leak test, reduced pressure test, flow test and pressure drop tests.
2. Design of test bench, panel size, threaded adaptors and interconnections..
3. Selection of gauges [G5] to read reduced pressure with least count of 1 psi which covers all range of aircraft cylinders.
4. Selection of Flowmeter [Fl and [F2] to read flow range of all aircraft cylinders.
5. Selection of high pressure and low pressure hoses in the circuit, to optimize the test results
achieved.
6. Selection of Valves [VI to V4] to optimize the test results of all the LRUs tested on this rig.
7. Positioning of Gauges, Flowmeters and Adaptors in the test panel, to avoid parallax error and considering Ease of Use.