37. Additional requirements for dissolved acetylene gas cylinders
.-Dissolved acetylene gas cylinder shall comply with following additional provisions, namely:-(i)The porous substance shall fill as completely as possible the cylinder into which the acetylene is compressed.(ii)The porosity of the substance shall not exceed 92 per cent and in no case shall be less than 75 per cent.(iii)Any solvent used shall not be capable of chemical reaction with the acetylene gas or with the porous substance or with the metal of the cylinder.(iv)If acetone is used as a solvent it shall comply with the requirements of IS: 170, the quantity of acetone including the gas in solution shall be such that the cylinder meets the requirements of additional tests specified in IS: 7312.(v)The valves of the cylinders shall not contain more than 70 per cent copper in their composition.(vi)The pressure in the cylinder shall not exceed 16 kgf/cm2 at a temperature of 150C.(vii)Every cylinder shall before being filled with porous mass be tested by hydrostatic pressure to a pressure of not less than 60 kgf/cm2. This pressure may be reduced to 53 kgf/cm2 if the cylinder is fitted with fusible plug. No cylinder which shows a permanent stretch in excess of 71/2 per cent of the total stretch suffered during hydrostatic stretch test shall be allowed.(viii)The safety relief devices, if fitted, shall operate at a pressure of 53 kgf/cm2 or at a temperature of 1000C + 40C/-20C.(ix)Every cylinder shall have permanently and conspicuously marked upon it or upon a brass plate soldered to it the name of the manufacturer and the words "Acetylene properly compressed into porous substance" and shall bear the following markings, namely:-(a)Serial number and identification of manufacturer;(b)Number of the standard;(c)Test pressure;(d)The date of hydrostatic stretch test with code mark of the place where the test was carried out;(e)Date of filling of porous mass;(f)Water capacity;(g)A symbol to indicate the nature of heat treatment;(h)Identification of porous mass and porosity percentage;(i)Tare weight (inclusive of valve);(j)Inspector's official mark;(k)Maximum gas capacity.
