42 BUILDING AND EQUIPMENT 
For proper and economical insulation the following types of pipe 
covering are recommended : 
Ammonia and Brine Lines.— 
Ist layer of tarred felt. 
2nd layer of 1” thick hair felt. 
3rd layer of tarred felt. 
4th layer of 1” thick hair felt. 
5th layer of tarred felt. 
6th layer of wove-felt paper. 
7th layer of 8-oz. canvas jacket, sewed on. 
8th layer of sizing and one coat of lead and oil paint. 
Each layer of hair felt must be securely wound with twine. 
Each laver of all material should be coated with hot asphalt, 
applied while hot, excepting layers, 6, 7 and 8. 
Special seals must be made at all flanges and fittings, and 
such flanges and fittings must be insulated independently. This 
arrangement will prevent damage to adjoining coverings, should 
fittings spring leaks. 
Before applying pitch or asphalt, the necessary precautions 
must be taken to have the pipes thoroughly dry and the asphalt 
or pitch must be hot. 
Steam Lines.— Air cell asbestos covering, or covering of 
equal insulating and lasting quality, one inch thick on pipes, 
and fittings, to be built up of asbestos cement to a correspond- 
ing thickness; smoothly finished and neatly canvassed, with 
metal bands at 18” intervals. Before putting on the metal bands 
the covering should receive two coats of asbestos cold water 
paint. 
Cold Water Lines.—Covering of wool felt, tar paper lined, 
sectional, one inch thick on pipes; fittings to be built up to a 
corresponding thickness with one inch hair felt, the entire line 
should be neatly finished with a graded mixture of Portland 
cement and asbestos cement, and canvas-jacketed and equipped 
with metal bands at 18” intervals. Before putting on the metal 
bands, the covering should receive two coats of asbestos cold 
water paint. 
Sanitary Arrangement of Machinery.—Milk pumps, milk 
pipes, milk troughs and other milk conveyors are, at best, ene- 
