1894 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



52 



Fig. 8. Stewart Strainer. 

 Suction Hose or Pipe 



The wire-lined suction hose, which is 

 furnished with machines requiring such a 

 connection, should be of the very best 

 quality. One and one-fourth-inch pipe 

 connections, although not flexible, nor as 

 easily changed as the same diameter 

 suction hose, possess the advantage of 

 not becoming leaky, are not affected by 

 the oil sprays, and cost very little when 

 their replacement becomes necessary. 



However, a suction hose permits the 

 washing out of the pump without wash- 

 ing out the tank, and it is usually long 

 enough to be placed in the storage tank 

 when using a tank filler. Plain hose will 

 collapse when the pump is operated, hence 

 it cannot be used in place of wire-lined 

 suction hose. 



Air Chambers 



The air chamber, in most cases, comes 

 next in order. This serves a two-fold 

 purpose; first, it acts as a storage for the 

 liquid under pressure; secondly, the air 



confined above the stored liquid is a 

 resilient body which tends to equalize 

 the pressure when there is a sudden in- 

 flux of liquid. When a pump has a large 

 capacity per stroke, and is equipped with 

 a small air chamber, it is not unusual to 

 see the indicator on the pressure gauge 

 swing through a range of fifteen to forty 

 pounds at every stroke of the pump. The 

 strain upon hose and connections is ex- 

 tremely severe, and the shock upon the 

 closing valve is comparable to the blow 

 from a hammer, when the pump is op- 

 erated under these conditions. The 

 capacity of the air chamber on power 

 outfits should be at least one-half as 

 great as the amount of liquid the pump 

 delivers per minute when it is operated 



tf^lM^M 



Fig. 9. (4) A simple plunger type relief valve 

 which is very sensitive to pressure variation 

 and has all of the apparent requisites of 

 durability. 



