(28) Occasionally a needle valve on a torch will begin to leak and it will be found necessary to grind it. Realizing that oil and grease are not to be used where oxygen is in evidence, the question is often brought up as to the proper lubricant to be used in doing this kind of work. Glycerine is used by most manufacturers, together with powdered glass or flour emery. In doing work of this kind the finished job is thoroughly washed with ether. Occasionally when piping oxygen lines through the shop, a screwed coupling will leak and there is a temptation to calk the same with white lead, but this should never be done, rather use lead oxide mixed with the glycerine for this purpose as it forms a paste which sets very rapidly and forms a hard, tough compound.
CHAPTER II
OPERATION
(29) In oxy-acetylene welding there are two gases used, as the name would indicate, namely, oxygen and acetylene. The first is used to intensify the flame and can in nowise be likened to the inflammable nature of the second. There is a great deal of oxygen present in the air we breathe. It is an odorless, tasteless, and colorless gas, as most of us are aware. In the commercial world oxygen is manufactured by the decomposition of water into its elements, oxygen and hydrogen, by the electrolytic process or is taken from the air by a reduction process and is stored in steel-drawn cylinders. These cylinders are drawn out of one piece of steel and are of considerable thickness throughout, having absolutely no seams, welded or otherwise. There is no filler nor absorbent used on the inside of these cylinders, as pure oxygen under pressure is not considered dangerous. The standardized sized oxygen cylinder is one which contains 200 cubic feet of gas fully charged. Oxygen is compressed in these cylinders at a pressure of 1800 pounds, at normal temperature, and this pressure does not vary to any great extent with change in temperature (as shown by table on page 29). There is attached to the tip of the steel cylinder, or “bottle,” as some workers call it, a double seating valve which has one seat operate when the cylinder is closed, and the other when the cylinder is wide open. A regulator is attached to this valve when working.
Fig. 17.—Sectional View of Oxygen Cylinder without Valve.
(Courtesy of the Linde Air Products Co.)
Fig. 18.—A Standard 200-foot Oxygen Cylinder.
TABLE SHOWING THE DIFFERENT PRESSURES OF OXYGEN—AT VARIOUS TEMPERATURES
| Temp. Deg. Fahr. | Press. Lb. Per Deg. | Temp. Deg. Fahr. | Press. Lb. Per Deg. | Temp. Deg. Fahr. | Press. Lb. Per Deg. | Temp. Deg. Fahr. | Press. Lb. Per Deg. |
|---|---|---|---|---|---|---|---|
| 0 | 1568 | 25 | 1654 | 50 | 1739 | 75 | 1824 |
| 1 | 1572 | 26 | 1657 | 51 | 1743 | 76 | 1828 |
| 2 | 1575 | 27 | 1660 | 52 | 1746 | 77 | 1831 |
| 3 | 1579 | 28 | 1664 | 53 | 1749 | 78 | 1835 |
| 4 | 1582 | 29 | 1667 | 54 | 1753 | 79 | 1838 |
| 5 | 1585 | 30 | 1671 | 55 | 1756 | 80 | 1842 |
| 6 | 1589 | 31 | 1674 | 56 | 1760 | 81 | 1845 |
| 7 | 1592 | 32 | 1678 | 57 | 1763 | 82 | 1848 |
| 8 | 1596 | 33 | 1681 | 58 | 1766 | 83 | 1852 |
| 9 | 1599 | 34 | 1684 | 59 | 1770 | 84 | 1855 |
| 10 | 1603 | 35 | 1688 | 60 | 1773 | 85 | 1859 |
| 11 | 1606 | 36 | 1691 | 61 | 1777 | 86 | 1862 |
| 12 | 1609 | 37 | 1695 | 62 | 1780 | 87 | 1865 |
| 13 | 1613 | 38 | 1698 | 63 | 1784 | 88 | 1869 |
| 14 | 1616 | 39 | 1701 | 64 | 1787 | 89 | 1872 |
| 15 | 1620 | 40 | 1705 | 65 | 1790 | 90 | 1876 |
| 16 | 1623 | 41 | 1708 | 66 | 1794 | 91 | 1879 |
| 17 | 1626 | 42 | 1712 | 67 | 1797 | 92 | 1883 |
| 18 | 1630 | 43 | 1715 | 68 | 1800 | 93 | 1886 |
| 19 | 1633 | 44 | 1719 | 69 | 1803 | 94 | 1889 |
| 20 | 1637 | 45 | 1722 | 70 | 1807 | 95 | 1893 |
| 21 | 1640 | 46 | 1725 | 71 | 1811 | 96 | 1895 |
| 22 | 1643 | 47 | 1729 | 72 | 1814 | 97 | 1900 |
| 23 | 1647 | 48 | 1732 | 73 | 1818 | 98 | 1903 |
| 24 | 1650 | 49 | 1736 | 74 | 1821 | 99 | 1906 |
| 100 | 1910 |