Figure 5-13.Chain clamps quickly align pipe fittings of any description.
The Linde Company has a method of fusion welding
that is remarkably fast and produces welds of high
quality. Anyone can use this process for welding pipe if
they adhere to the following conditions:
1. Use an excess fuel-gas flame.
2. Use a welding rod containing deoxidizing
3. Use the backhand welding technique.
The following is a brief explanation of the pre-
viously mentioned conditions:
1. EXCESS FUEL-GAS FLAME. The base metal
surface, as it reaches white heat, absorbs carbon from
the excess fuel-gas flame. The absorption of carbon
lowers the melting point of steel, thereby the surface
melts faster and speeds up the welding action.
2. SPECIAL WELDING ROD. The deoxidizing
agents in the recommended rod eliminates the
impurities and prevents excess oxidation of carbon.
Were it not for this action, considerable carbon, the most
valuable strengthening element of steel, would be lost.
Thus, even in high-carbon, high-strength pipe, the weld
metal is as strong as, or stronger than the pipe material.
3. BACKHAND TECHNIQUE. This technique
produces faster melting of the base metal surfaces. Also,
a smaller bevel can be used which results in a savings
of 20 to 30 percent in welding time, rods, and gases.
One of the most valuable tools you can use when
welding pipe is the pipe clamp. Pipe clamps hold the
pipe in perfect alignment until tack welds are placed.
They are quick opening and you can move or attach a
Figure 5-13 shows four different types of chain
clamps that are used for pipe welding. If these clamps
are not available, you can fabricate your own by welding
two C-clamps to a piece of heavy angle iron. A piece of
3/8-inch angle iron that is 4 inches by 4 inches by 12
inches is usually suitable. When working with small-di-
ameter pipe, you can lay it in apiece of channel iron to
obtain true alignment for butt welding. When the pipe
you are working on has a large diameter, you can use a
wide flange beam for alignment purposes.