Schedule XVII

(See rule 84)

Compression of oxygen and hydrogen produced by electrolysis of water.

1. Location of Electrolyser plant. – The room in which Electrolyser plant is installed shall be separate

from plant for storing and compressing oxygen and hydrogen and also the electric generator room.

2. Testing of purity-

(a) The purity of oxygen and hydrogen shall be tested by a competent person at least once in every

shift at the first posts:

(i) in the electrolysis room;

(ii) at the gasholder inlet; and

(iii) at the suction end of the compressor.

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

Provided, however, that if the Electrolyser 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 end of the compressor only.

(c) 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.

(d) Limit switch for gasholder – The bell of any gas holder shall not be permitted to go within 30

centimetres of its lowest position when empty and a limit switch shall be fitted to the gasholder in

which a manner as to switch off the compressor motor when the limit is reached.

(e) Provision of negative pressure switch – In addition to the limit switch in the gasholder-a sensitive

negative pressure switch shall be provided in or adjacent to the suction main for hydrogen close to

the gasholder and between gasholder and the hydrogen compressor to switch off the compressor

motor in the event of the gasholder being emptied to the extent as to cause vacuum.

(f) Purity of caustic soda – The water and caustic soda used for making limit shall be chemically pure

within pharmaceutical limits.

(g) 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 to 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 at the electric generator terminals.

(h) Coloring of gas pipes – Oxygen and hydrogen gas pipes shall be painted with distinguishing colors

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.

(i) Use of flame proof fitting – All electric wiring and apparatus in the electrolyser room shall be of

flameproof construction or enclosed in flameproof fitting and no naked light or flame shall be

allowed to be taken either in the electrolyser room or where compressor and filling of the gases is

carried on and such warning notices shall be exhibited in prominent places.

(j) Prohibition of hot work – No part of the electrolyser plant and the gasholders 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.

(k) Repair, Preventive Maintenance, etc. to be done under supervision – No work or operation, 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 repair shall be switched

on to the electrolyser 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 by the polarity as required by paragraph 7.

(l) Checking of plant – Every part of the electrolyser plant and the gasholders and compressor shall

have a regular schedule of overhaul and checking and every defect noticed shall be rectified

forthwith.