The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Care And Repair Of The House
Properties and Structure of Insulating
Materials.
The covering should be fire resistant and a poor conductor of heat. These qualities are found in asbestos air cell, asbestos cement, magnesia, mineral (or rock wool), and similar coverings. The application of some of these materials is described in the following paragraphs:
The air-cell covering is made of layers of corrugated asbestos paper wrapped in canvas. It is manufactured in sections 3 feet long in the shape of hollow cylinders split lengthwise on one side so that it may be readily placed around the pipe. (See fig. 12.) The covering is made in several thicknesses and for various pipe sizes. Each section has a canvas lap to be pasted over the longitudinal joint and a canvas flap at one end to be pasted over the joint between sections. To further bind the covering and to make a neat-looking job, metal bands are furnished, to be placed about 18 inches apart, over the joints between sections and around the middle of each section.
For insulating boilers and pipe fittings, such as valves, ells, and tees, where the use of fabricator coverings is not practicable, asbestos cement may be used. This material, because of its natural cell-like structure and fire-resisting qualities, serves the same purpose as the pipe covering.
Tools.
A steel tape measure, plasterer's trowel, hand saw, sharp pocket knife, pliers, a metal tub or similar container for mixing cement, a pan or dish for paste, and a small, flat paste brush.
Materials.
A 4-ply, or 1 inch thick, asbestos air-cell covering is frequently used for insulating pipes in home heating plants. To estimate the quantity needed, carefully measure between fittings all pipes that are to be covered and combine measurements for each size of pipe to obtain the total linear feet of each size of covering. Metal band fasteners are furnished with the covering.
To estimate the quantity of asbestos cement needed to cover the boiler and pipe fittings, measure the entire surface of the boiler to be covered, together with the surfaces of pipe fittings, and compute the square-foot area of each. A 100-pound bag of cement will cover from 20 to 25 square feet of surface to a thickness of 1 inch. Some brands are sold also in 10-pound bags.
