Loss of Heat from Covered Steam Pipes 13 



Jacobus' tests without assuming a different quality of "Hair 

 Felt." 



The three coverings, "Rock Wool," " Mineral Wool " and 

 "Champion Mineral Wool," are all mineral wools, and it is in- 

 teresting to note that the chemical composition of the first two is 

 almost identical, both having about 18 per cent, of magnesia, 

 while the " Champion Mineral Wool " has only 3 per cent. 



130 POUNDS STEAM PRESSURE TEST. 



The results of this test have not previously been published. 

 The writer was personally connected with it and worked up the 

 original report. 



The test pipes were 2-inch standard steam pipes 80 feet long. 



The test was forty -eight hours long, and was made in 1896. 



B. T. U. Computed 



Thickness per sq. ft. Pipe Value 



Name of Covering of Covering. Surface per hr. of C. 



Magnesia 1.09" 155.8 .534 



Manville 1.31" *57- -606 



Asbestos Fire Felt i.oo" 198.0 .680 



The average steam pressure was 128.7; temperature corre- 

 sponding, 354.7 ; average temperature of air 80. i. 



NORTON'S TESTS. 



These tests were published in the Transactions A. S. M. E., 

 Vol. XIX. They were made in 1896-1897. 



They are interesting inasmuch as the pipes under test were 

 filled with oil, heated by an electric current passing through a 

 coil. The oil was agitated by two small propellers. 



We have already shown that the outside of a covered pipe 

 carrying steam takes the temperature of the steam, and in these 

 experiments it would take the temperature of the oil, and for equal 

 temperatures the loss of heat would be the same. The following 

 computed values of C bear out this opinion fairly well : 



B. T. U. Corn- 

 Temp, of Temp, of per sq. ft/ puted 

 Size Thickness Steam, Air, Pipe Value 



of of Degs. Degs. Surface of 



Name of Covering. Pipe. Covering. Fahr. Fahr. per hour. C. 



Magnesia 4" 1.12" 388 72 147 .52 



Manville 4" 1.25" 388 72 143 .55 



Asbestos Air Cell... 4" 1.12" 388 72 166 .60 



The corresponding steam pressure would be 201 pounds. 



