1. Title of the invention
Design and Development of Oxygen Charging Test Set for Gaseous Oxygen Charging 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, with Gaseous Oxygen from Mother Cylinder using a Test Bench.
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 Set with available Resources, to charge/fill Gaseous Cylinders 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 includes Main Oxygen Cylinders and Emergency
Oxygen Set. These Units needs to be charged with Breathing Oxygen before
fitment to Aircraft. This test facility is developed to charge Breathing Oxygen
to these units in Lab. '

9. Brief description of drawings
FIG. 1: Schematic Diagram of Oxygen Charging Test Set FIG. 2: Drawing of manifold [M] FIG- 3: Drawing of Test Bench [T]
10. Statement of invention
This invented Test Rig is useful to Charge/fill Breathing Oxygen to Aircraft Cylinders 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 Emergency Oxygen Set of various Aircraft.
b. The Basic functions of the Rig include Charging of Main Oxygen and
Emergency Oxygen Cylinders.
c. The test Facility consist of Connecting panel [PI], Junction Box [J], Test
Bench [T] and Hoses [H]for inter connection.
d. The Connecting panel [PI] consists of an aluminium plate with three Oxygen
on off valves [VI], [V2] and [V3].
e. The Junction box [J] consists of a metal block [M], Pressure gauge [Gl] and
three Brass adaptors.
f.' The Metal block is made of Stainless steel with holes drilled as per design for interconnection of ports.
g. The pressure gauge [Gl] is to indicate the pressure in Oxygen Mother Cylinders [CI, C2, and C3].
h. The brass adaptors' are to connect the junction box to test bench [T] and connecting panel [PI].

i. The Test Bench [T]consists of a. panel [P2] made up of steel frame with aluminium sheets, gauge [G2] for showing source pressure of Mother cylinder [CI], an on-off valve [R/V4] to charge the Aircraft Cylinder [C4], a gauge [G3] to show the charging pressure and a vent valve [V]to" vent residual pressure in the hoses [H] after charging.
j. The interconnection of the panels and test bench is done by oxygen cleaned hoses as per Fig 1. The Mother cylinders [CI, C2, C3], connecting panel [PI] and junction box [J] is outside the charging room. The test bench [T] and aircraft Cylinder [C4] is inside the charging room. The pressure of Mother Cylinder increases in order [CI, C2 and C3]. The system is designed for maximum utilization of mother cylinder oxygen content.
k. The procedure of operating the Test Set is as follows.
I. Initially it is ensured that all-the valves in the system are in closed position. The oxygen mother cylinders [CI, C2, and C3] are opened slowly.
m. The valve VI is opened slowly'and the pressure of mother cylinder [CI] is shown on gauge [Gl].
n. The gauge G2 also shows the pressure in mother cylinder [CI]. The system is purged to clear any impurities.
o. The aircraft cylinder [C4] is connected to the test bench [T] with Hose [H13].
p. The valve [V4] is opened slowly to charge the Aircraft Cylinder [C4],
q. Once the pressure of [C4] equals pressure of mother cylinder [CI], the valve [V4] and [VI] is dosed.

r. Valve [V2] is opened to connect Mother Cylinder [C2] to the system. Then Valve [V4] is opened till pressure in [C4] equals [C2]. The valve [V4] and [V2] is closed.
s. Further, valve [V3] and then valve [V4] is opened till pressure in [C4] reached the OEM stipulated charging pressure. Then the valve [V4] and [V2] is closed.
t. Valve [V5] is opened to vent the line pressure from the system. The Aircraft Cylinder [C4] is removed from the system.
u. The same process is followed to charge another Aircraft Oxygen cylinder. After the charging is complete, all valves are closed.

Claims
1. Design of the Oxygen charging Test Set using Manifold [M], Junction box [J], Connecting Panel [PI] and Test Bench [T].
2. Selection of dimensions for the block, oxygen flow paths, counter-bore size and thread size in the Manifold [M] for charging Cylinders with cascading affect.
3. Design of Manifold [M].
4. Design of the Test Bench [T].
5. Selection of three Mother Cylinders [CI, [C2,C3] and its connection to the Manifold [M] through Junction box [J] and Connecting Panel[Pl], achieving optimum charging of Aircraft Cylinder[C4] by maximum utilization of the three Mother Cylinders.