Acetylene, the Principles of Its Generation and Use Part 7

5. Alterations to any part of an apparatus which involve the operations of soldering or riveting, &c., _i.e._, in which a fire must be used, or a spark may be produced by the impact of hammer on metal, must only be carried out by daylight in the open air after the apparatus has been taken to pieces. First of all the plant must be freed from gas. This is to be done by filling every part with water till the liquid overflows, leaving the water in it for at least five minutes before emptying it again.

6. The apparatus house must not be used for any other operation, nor employed for the storage of combustible articles. It must be efficiently ventilated, and always kept closed. A notice must be put upon the door that unauthorised persons are not permitted to enter.

7. It in forbidden to enter the house with a burning lantern or lamp, to strike matches, or to smoke therein.

8. A search for leaks in the pipes must not be made with the aid of a light.

9. Alterations to the service must not be made while the pipes are under pressure, but only after the main c.o.c.k has been shut.

10. If portable apparatus, such as described in I., 12, are connected to the burners with rubber tube, the tube must be fortified with an internal or external spiral of wire. The tube must be fastened at both ends to the c.o.c.ks with thread, copper wire, or with ring clamps.

11. The preparation, storage, and use of compressed or liquefied acetylene is forbidden. By compressed acetylene, however, is only to be understood gas compressed to a pressure exceeding one effective atmosphere. Acetylene compressed into porous matter, with or without acetone, is excepted from this prohibition.

12. In the case of plants serving 50 lights or less, not more than 100 kilos. of carbide in closed vessels may be kept in the apparatus house besides the drum actually in use.

A fresh drum is not to be opened before the previous one has been two- thirds emptied. Opened drums must be closed with an iron watertight lid covering the entire top of the vessel.

In the case of apparatus supplying over 500 lights, only one day's consumption of carbide must be kept in the generator house. In other respects the store of carbide for such installations is to be treated as a regular carbide store.

13. Carbide drums must not be opened with the aid of a flame or a red-hot iron instrument.

14. Acetylene apparatus must only be attended to by trustworthy and responsible persons.

The rules issued by the AUSTRIAN GOVERNMENT in 1905 for the installation of acetylene plant and the use of acetylene are divided into general enactments relating to acetylene, and into special enactments in regard to the apparatus and installation. The general enactments state that:

1. The preparation and use of liquid acetylene is forbidden.

2. Gaseous acetylene, alone, in admixture, or in solution, must not be compressed above 2 atmospheres absolute except under special permission.

3. The storage of mixtures of acetylene with air or other gases containing or evolving free oxygen is forbidden.

4. A description of every private plant about to be installed must be submitted to the local authorities, who, according to its size and character, may give permission for it to be installed and brought into use either forthwith or after special inspection. Important alterations to existing plant must be similarly notified.

5. The firms and fitters undertaking the installation of acetylene plant must be licensed.

The special enactments fall under four headings, viz., (_a_) apparatus; (_b_) plant houses; (_c_) pipes; (_d_) residues.

In regard to apparatus it is enacted that:

1. The type of apparatus to be employed must be one which has been approved by one of certain public authorities in the country.

2. A drawing and description of the construction of the apparatus and a short explanation of the method of working it must be fixed in a conspicuous position under cover in the apparatus house. The notice must also contain approved general information as to the properties of calcium carbide and acetylene, precautions that must be observed to guard against possible danger, and a statement of how often the purifier will require to be recharged.

3. The apparatus must be marked with the name of the maker, the year of its construction, the available capacity of the gasholder, and the maximum generating capacity per hour.

4. Each const.i.tuent of the plant must be proportioned to the maximum hourly output of gas and in particular the available capacity of the holder must be 75 per cent. of the latter. The apparatus must not be driven above its nominal productive capacity.

5. The productive capacity of generators in which the gasholder has to be opened or the bell removed before recharging, or for the removal of sludge, must not exceed 50 litres per hour, nor may the charge of carbide exceed 1 kilo.

6. Generators exceeding 50 litres per hour productive capacity must be arranged so that they can be freed from air before use.

7. Generators exceeding 1500 litres per hour capacity must be arranged so that the acetylene, contained in the parts of the apparatus which have to be opened for recharging or for the removal of sludge, can be removed before they are opened.

8. Automatic generators of which the decomposing chambers are built inside the gasholder must not exceed 300 litres per hour productive capacity.

9. Generators must be arranged so that after-generation cannot produce objectionable results.

10. The holder of carbide-to-water generators must be large enough to take all the gas which may be produced by the introduction of one charge of carbide without undue pressure ensuing.

11. The maximum pressure permissible in any part of the apparatus is 1.1 atmosphere absolute.

12. The temperature in the gas s.p.a.ce of a generator must never exceed 80 C.

13. Generating apparatus, &c., must be constructed in a workmanlike manner of metal capable of resisting rust and distortion, and, where the metal comes in contact with carbide or acetylene, it must not be one (copper in particular) which forms an explosive compound with the gas.

c.o.c.ks and screw connexions, &c., of bra.s.s, bronze, &c., must always be kept clean. Joints exposed to acetylene under pressure must be made by riveting or welding except that in apparatus not exceeding 100 litres per hour productive capacity double bending may be used.

14. Every apparatus must be fitted with a safety-valve or vent-pipe terminating in a safe place in the open, and of adequate size.

15. Every apparatus must be provided with an efficient purifier so fitted that it may be isolated from the rest of the plant and with due consideration of the possible action of the purifying material upon the metal used.

16. Mercury pressure gauges are prohibited. Liquid gauges, if used must be double the length normally needed, and with a c.o.c.k which in automatic apparatus must be kept shut while it is in action.

17. Proper steps must always be taken to prevent the apparatus freezing.

In the absence of other precautions water-seals and pressure-gauges must be filled with liquid having a sufficiently low freezing-point and without action on acetylene or the containing vessel.

18. Signal devices to show the position of the gasholder bell must not be capable of producing sparks inside the apparatus house.

19. Leaks must not be sought for with an open flame and repairs requiring the use of a blow-pipe, &c., must only be carried out after the apparatus has been taken to pieces or freed from gas by flooding.

20. Apparatus must only be attended to by trustworthy and responsible adults.

21. Portable apparatus holding not more than 1 kilo. of carbide and of not more than 50 litres per hour productive capacity, and apparatus fixed and used out of doors are exempt from the foregoing regulations except Nos. 11 and 12, and the first part of 13.

In regard to (_b_), plant houses, it is enacted that:

1. Rooms containing acetylene apparatus must be of ample size, used for no other purpose, have water-tight floors, be warmed without fireplaces or chimneys, be lighted from outside through an air-tight window by an independent artificial light, have doors opening outwards, efficient ventilation and a store of sand or like material for fire extinction.

Strangers must be warned away.

2. Apparatus of not more than 300 litres per hour productive capacity may be erected in bas.e.m.e.nts or annexes of dwelling houses, but if of over 50 litres per hour capacity must not be placed under rooms regularly frequented. Rooms regularly frequented and those under the same must not be used.

3. Apparatus of more than 300 litres per hour productive capacity must be erected in an independent building at least 15 feet distant from other property, which building, unless it is at least 30 feet distant, must be of fire-proof material externally.

4. Gasholders exceeding 280 cubic foot in capacity must be in a detached room or in the open and inaccessible to strangers, and at least 30 feet from other property and with lightning conductors.

5. In case of fire the main c.o.c.k must not be shut until it is ascertained that no one remains in the room served with the gas.

6. All acetylene installations must be known to the local fire brigade.