HOT WATER INSTALLATION 



179 



Fig. 95. Diagram showing under-bench method of hot 

 water piping. A and B flow pipes; C and D heating coils 



fering with the circulation in the other coils. 

 The valves should be of a type which, when 

 open, cause as little resistance to the flow of 

 water as possible. 



Length of Coils. The length of the coils 

 which may be used depends: (i) Upon the 

 height of the column of water; (2) upon the 

 size of the pipes which make up the coils; 

 and (3) the amount of friction in the coils 

 and fittings. The length of coils which may 

 be satisfactorily used with pipes of various 

 sizes are given in the following table. 



