Schedule B XVII

Compression of oxygen and hydrogen produced by electrolysis of water

1. Location of electrolyte plant.—The room in which electrolysis 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.-

I. The purity of oxygen and hydrogen shall be 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.

II. The purity figures shall be entered in a register and signed by the

persons carrying out such test :

Provided, however, that if the electrolysis 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 be fitted 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

electrolyser 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 electrolysis plant and the gas holders

and compressor shall have a regular schedule of overhaul and checking and

every defect noticed shall be rectified forthwith.