Schedule XVII

Compression of oxygen and hydrogen produced by electrolysis of water


1. Location of electrolyte plant - The room in which electrolyser plant is installed shall be separate from the plant for storing and compressing the oxygen and hydrogen and also the electric generator room.


2. Testing of purity - (1)The purity of oxygen and hydrogen shall tested by a competent person at least once in every shift at the following posts:-


(a) in the electrolysis room;

(b) at the gas holder inlet; and

(c) at the suction and of the compressor.


(2) The purity figures shall be entered in a register and signed by the persons carrying out such test:


Provided, however, that if the electolyser plant is fitted with automatic recorder of purity of oxygen and hydrogen with alarm lights, it shall be sufficient if the purity of gases is tested at the suction and of the compressor only.

3. Restriction as to the compression - The oxygen and hydrogen gases shall not be compressed if their purity as determined under paragraph 2 above falls below 98% at any time.


4.                  Limit switch for gas holder - The bell of any gas holder shall not be permitted to go within the 30 centimetres of its lowest position when empty and a limit switch shall befitted to the gas holder in such a manner as to switch off the compressor motor when the limit is reached.


5.                  Provision of negative pressure switch - In addition to the limit switch in the gas holder, a sensitive negative pressure switch shall be provided in or adjacent to the suction main for hydrogen close to the gas holder and between the gas holder and the hydrogen compressor to switch off the compressor motor in the event of the gas holder being emptied to the extent as to cause vacuum.


6.                  Purity of caustic soda - The water and caustic soda used for making lye shall be chemically pure within pharmaceutical limits.


7.                  Precautions against reversal of polarity - Electrical connections at the electolyser cells and at the electric generator terminals shall be so constructed as to preclude the possibility of wrong connections leading to the reversal of polarity and in addition an automatic device shall be provided to cut off power in the event of reversal of polarity owing to wrong connections either at the switch board or at the electric generator terminals.


8.                  Colouring of gas pipes - Oxygen and hydrogen gas pipes shall be painted with distinguishing colours and in the event of leakage at the joints of the hydrogen gas pipe, the pipe after reconnection shall be purged of all air before drawing in hydrogen gas.


9.                  Use of flameproof fittings - All electrical wiring and apparatus in the electrolyser room shall be of flameproof construction or enclosed in flameproof fittings and no naked light or flame shall be allowed to be taken either in the electrolyser room or where compression and filling of the gases is carried on and such warning notices shall be exhibited in prominent places.


10.             Prohibition of hot work - No part of the electrolyser plant and the gas holders and compressor shall be subjected to welding, brazing, soldering or cutting until steps have been taken to remove any explosive substance from that part and render the part safe for such operations and after the completion of such operations no explosive substance shall be allowed to enter that part until the metal has cooled sufficiently to prevent risk of explosion.


11.             Repair, etc. to be done under supervision - No work or operations, repair or maintenance shall be undertaken except under the direct supervision of a person who, by his training, experience and knowledge of the necessary precautions against risk of explosion is competent to supervise such work. No electric generator after erection or repairs shall be switched on/the electrolysers unless the same is certified by the competent persons under whose direct supervision erection or repairs are carried on to be in a safe condition and the terminals have been checked for the polarity as required by paragraph 7.


12.                 Checking of plant - Every part of the electrolyser plant and the gas holders and compressor shall have a regular schedule of overhaul and checking and every defect noticed shall be rectified forthwith.