Abstract: An assembly arranged for mounting to a pipe to be welded is provided, wherein the assembly includes a support pipe having a counterweight slidably mounted therealong. The support pipe includes a V-shaped lock receiving the pipe to be welded, with a clamp chain arranged for securing the pipe to be welded relative to the V-shaped lock, whereupon sliding of the counterweight relative to the support pipe provides for counter-balancing of the pipe to be welded in an adjustable manner.

Abstract: The invention is a very highly refined arabinogalactan gum falling within the molecular weight range of 6,000-2,500,000 and having a tannic acid equivalent of less than about 0.5 mg/g. The preferred product will have a molecular weight within the range of 6,000-1,300,000 and tannic acid equivalent no higher than about 0.25. The product is nearly colorless and is tasteless and odorless. it is prepared by first making a crude water extract of a natural source such as larch wood. This extract is next refined by the addition of an active MgO to precipitate the bulk of the lignans and iron containing compounds. Following that it is processed through a membrane no larger than about 0.45 .mu.m to remove any species having molecular weights in excess of about 2,500,000. The permeate may then be treated on successively smaller membranes down to about 6,000 daltons.