ISO 15738 pdf download – Ships and marine technology一Gas inflation systems for inflatable life-saving appliances

ISO 15738 pdf download – Ships and marine technology一Gas inflation systems for inflatable life-saving appliances.
4.1 Type and quantity
The gas used for inflation shall be non-toxic, for example carbon dioxide, The type and quantity shall pwvide a sufficient rate of inflation to allow the complete system to meet me specified inflation performance requirements tar the equipment In which it is installed.
4.2 Dryness
If the gas used is carbon dioxide. its moisture content shad be no more man 150 parts water per 1 mIllion parts of gas by mass.
5 Gas-cylinder valve
5.1 General
5.1.1 The cylinder valve shall be fitted with a safety relief device which will vent gas prior to damage to the cylinder frpm overpressurization.
5.1.2 Means shall be provided to proteci the threads on the cylinder valve for attachment of the high-pressure hoses and operating head from damage during storage and transit.
5.1.3 A cylinder valve constructed from aluminium alloy shall be anodized and may only be used with an aluminium cylinder, unless it is galvanically isolated tram the cylinder.
5.1.4 Each combination of cylinder valve and cylinder which are of differing rnatenals, or any aluminium alloy cylinder valve used with an aluminium cylinder, shall be subjected to the salt water exposive test as described in
5.2.9.
5.1.5 If the cylinder valve Is for use with carbon dioxide, a syphon tube shall be used. It shall be ensured that, In all operational positions of the cylinder, the syphon tubes open end remains submerged in the liquid gas.
5.2 Testing
5.2.1 Satety relief test
It shall be demonstrated that the salety relief device on me gas-cylinder valve, when fitted to an approved cylinder in accordance with the instructions of me cylinder valve manufacturer, will operate at a pressure not greater man the highest cylinder test pressure for which it is rated.
5.2.2 Proof-load test
The bodies of six cylinder valves shall be subected to an Internal hydraulic pressure of the greater o128 MPa. or the highest cylinder test pressure for which the valve is rated, for a period of 60s.
On there shall not be any signs of leakage or damage.
One of the gas-cylinders and valves used in the long-term leak test, ater being fully discharged of gas, shall be
dropped 9 times from a height of 300 mm at an angle of 45° onto a concrete floor covered with hardboard so that the
valve receives the full force of the impact.
The test shall be repeated with the cylinder angled in a plane at 90° to the original test.
On completion of the above tests, the cylinder shall be stood vertically on its base, and pushed over so that, as it flls,,
the cylinder valve strikes a steel stop secured to the floor. The height of the steel stop shall be not less than halt the
diameter of the cylinder used fior the test. The test shall be repeated 12 times.
On completion, the valve shall be carefully examined, if necessary using a flaw detector. There shall not be any signs
of flaw or fracture other than superticial surface damage.
An approved gas-cylinder, with a mass of at least 8,165 kg, fted with the cylinder valve shall be dropped three times
from a height of 1,5 m onto an aluminium sheet so that the valve takes the full force of the impact at an angle of 60° to the sheet.
The aluminium sheet shall be removed and the test repeated with a single drop onto a concrete foor
On completion, the valve shall be removed from the cylinder and caretully examined. There shall not be any signs of
flaw or fracture other than superficial surtace damage.
5.2.8 Torque test
An approved CO2 gas-cylinder shall be valved and devalved in accordance with the instructions of the valve
manutacturer. Repeat tor a total of six cycles.
On completion, carefully examine the valve threads. There shall not be any signs of stripping or damage.
5.2.9 Salt water exposure test
This test is aplicable to combinations of cylinder valve and approved cylinder which are of dftering materials, or any
aluminium-alloy cylinder valve used with an approved aluminium cylinder.
The complete assembly shall be assembled in accordance with the instructions of the cylinder valve manufacturer, and partially immersed in a 3 % sodium chloride solution for a period of 18 months, or aternatively be exposed to a salt water spray (5 % sodium chloride solution) at a temperature of 35 °C土3 °C for 160 h without iterruptin.
On completion of either of these tests, the mass of the gas charge shall not have been reduced by more than 2 %， and both the valve and operating head shall function in a satisfactory manner.
NOTE This test may be pertormed simultaneously with the test specitied in 6.24.