This is intended to prevent the dangerous escape of gas.
(d) The water or carbide supply to the generating chamber must be so arranged that gas will be generated long enough in advance of the exhaustion of the supply already in the gasholder to allow the using of all lights without exhausting such supply.
This provides for the continuous working of the apparatus under all conditions of water-feed and carbide charge, and it obviates the extinction of lights through intermittent action of the machine.
(e) No valves or pet-cocks opening into the room from the gas- holding part or parts, the draining of which will allow an escape of gas, are permitted, and condensation from all parts of the apparatus must be automatically removed without the use of valves or mechanical working parts.
Such valves and pet-cocks are not essential; their presence increases the possibility of leakage. The automatic removal of condensation from the apparatus is essential to the safe working of the machine.
U-traps opening into the room from the gas-holding parts must not be used for removal of condensation. All sealed drip connexions must be so arranged as to discharge gas to the blow-off when blown out, and the seals must be self-restoring upon relief of abnormal pressure.
(f) The apparatus must be capable of withstanding fire from outside causes.
Sheet-metal joints must be double-seamed or riveted and thoroughly sweated with solder. Pipes must be attached to sheet-metal with lock-nuts or riveted flanges.
This prohibits the use of wood or of joints relying entirely upon solder.
(g) Gauge glasses, the breakage of which would allow the escape of gas, must not be used.