CHAPTER XIX 

 Spray Machinery — General Principles 



Several important considerations should l^e taken into account in 

 the selection and care of spray machinery and appliances. Chief 

 among these are the following : 



The spray pump should be of adequate size for the work for which it 

 is intended to be used. As will l)e noted below, there are many different 

 sizes and styles of pumps, ranging from the hand atomizer with a 

 capacity of a quart or less of spray material, and suitable only for a 

 very limited use, to the heavy power outfit fitted with a 200-gallon tank, 

 and capable of throwing a stream 70 feet into the air. Either 

 outfit would be absolutely unsuited to the work of the other. While 

 these two examples are at the extremes, the same principle holds good, 

 in lesser form, to other outfits that grade in between these two. It 

 is poor economy to save four or five dollars on an outfit and expend 

 several times that amount each season in extra labor and time. The 

 first question to be decided, therefore, is that of the type and size of 

 pump that will be best adapted to the work in hand. 



Whatever the style of pump decided on, it must be made of proper 

 materials. Some of the spray solutions in common use have a corroding 

 action on iron. The only material that will withstand their attack is 

 brass or bronze, and care should be taken to get a piimp in which all the 

 metal working parts that come into contact with the liquid are of heavy 

 brass or similar alloy. This applies to the inside of the cyhnder, the 

 piston, the valves, valve seats, and any other submerged parts where 

 close fitting is essential to the smooth and satisfactory working of the 

 apparatus. 



Lately pumps have been placed on the market in which the inside 

 of the cylinder is coated with a heavy, white enamel. If this is so 



