Equipment for generation of 600 bar pressure
FIELD OF INVENTION:Equipment for generation of 600 bar pressure is based on Mechanical assembly
of piston and cylinder that acts as pump to generate the required pressure.
BACKGROUND: This equipment is developed for testing of Protected Memory Module (PMM) that is a
data storing device required for storing the recorded data transmitted from Solid State Flight data
Recorder (SSFDR) fitted on the platform into solid state non-volatile memory. It can store the aircraft
audio & parameter data. The stored data is protected against stipulated crash conditions to enable its
subsequent retrieval and decoding by Ground Replay Equipment. The stipulated crash conditions are
based on the European document for SSFDR ie ED-112 and international standard TSO-c-124(a).
DETAIL DESCRIPTION: The cavity is large enough to possess unit of size approximately
124mmX134mmX196mm. The test unit is placed within test cavity and water is filled to the top. Pressure
intensifier raises the pressure that comprises of two chambers. Air chamber area is 15 times than area of
the water chamber, thus intensifying the pressure by 15 times in each move.
The air cylinder of the intensifier is properly designed to move the piston unit back and forth by controlling
valves on the control panel. The nitrogen cylinder is supplied with about 100 bar nitrogen pressure.
To generate High pressure, as in Fig.1 water is filled in water chamber and valve V1, V3 is closed as per
schematic diagram of deep sea pressure test of fig.1. Applied pressure of air chamber get amplified by 15
times. Thus piston moves forward and pressure of water increases in cavity. The process continues till
the piston in the water chamber hits the dead end. Now valve V2 is closed and pressure inside the air
chamber is released. Valve V1 is opened and then the piston is retracted. When the water chamber is
filled, valve V1 is closed. Pressure is applied in the air chamber again till the pressure inside the air
chamber reaches the pressure of the cavity. Then the valve V2 is opened and the air pressure is further
increased gradually. The process is repeated until the desired pressure is achieved inside the test cavity.
CAVITY SUB ASSEMBLY
It is made up of thick walled cylinder using high manganese steel. The presence of manganese
suppresses the corrosion of steel exposed to salt water .A cover on top (2) of same material is properly
designed so as to place a U-shaped seal to avoid leakage even at high pressure . The cover is screwed
to the cavity with the help of screws. On the side wall a pressure gauge capable of measuring pressure
up to 70-80 MPa is fitted. Also the cavity is connected to a pressure intensifier with a high pressure hose.
At the center of the top cover a needle valve has been provided to let the trapped air, if any, escape.
In order to minimize the volume of water in cavity, we have placed four dead additional blocks. The gap
has to be filled with sea.
PRESSURE INTENSIFIER SUB ASSEMBLY
Refer Fig.2. The sea water is compressed (18) between the middle (16) and the front plate (15) using ‘O’
rings (25,26) for sealing. Similarly the gas cylinder (19) is compressed between the rear (17) and middle
plate.
The tie rods (20) are used to compress all the three plates and both the air and water cylinders together.
To control the motion of the piston, appropriate openings are made to the gas cylinder, which are
connected to the control panel subassembly. A hole in the middle plate is used to ensure that the piston is
retracted fully at the beginning of the test. The rubber pads (28,29) are attached to the rear and the
middle plate to avoid sudden impact of the piston with the walls of the plates. Through a hole at center in
rear plate desired pressure is maintained on the piston. A ball (31) valve is attached at the top portion of
the water cylinder to let the entrapped air escape and to provide water into the test cavity, during the
beginning of the test.

CLIAMS:
1. Can generate pressure of 600 bar/60MPa that is equivalent to pressure of 6Km deep in sea water
2. Can be used for testing the unit of size approximately 124mmX134mmX196mm.
3. can be used for sea water immersion test that is pressure of equivalent to three meter height for the duration of 30 days.