20 



AGRICULTURE HANDBOOK 134, U.S. DEPT. OF AGRICULTURE 



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PN-4729 



Figure SS. — Collecting tank mounted on a truck body. 

 This type of assembly does not require special rigs, but 

 an additional man is needed to empty the pails into the 

 tank. 



PN-n3n 

 Figure Si. — Additional labor is required to lift sap to a 

 tank mounted on a trailer. 



similar to those used in milking machines that 

 prevent milk from entering the pump. If sap 

 reaches the motor, it causes serious damage. 



A 1,000-gallon tank can be emptied and put 

 back into operation in only a few minutes. The 

 suction line is a 1-inch hose, which will pick up 

 30 gallons of sap per minute. Instead of a slow- 

 acting valve in the suction line, a tapered plug 

 is used in the pickup end of the hose. This plug 

 is removed just before the hose is submerged in 

 the sap in the tank or bucket to be emptied. 



PN-4731 



Figure S5. — For large operations or for collection from 

 roadside trees extending along several miles of roads, 

 the large tank trailer is desirable. 



If a closed tank and an engine manifold 

 vacuum system is not available, a pump-and- 

 vacuum system can be used (2). In this novel 

 system, an air-cooled gasoline motor operates a 

 pump which, in turn, creates a vacuum in a 

 small tank. The sap is discharged into a conven- 

 tional collecting tank. 



Regardless of how the vacuum in the suction 

 (sap pickup) line is developed, this method of 

 collecting sap is efficient and fast, causes a 

 minimum of loss due to spillage, and can be 

 used for collecting sap from the conventional 

 metal bucket, from the large 20-gaIlon con- 

 tainer, and from small and large storage tanks. 

 Whether or not the collecting tank has a vac- 

 uum line pickup, the tank must be as large as 

 roads and other conditions will permit. The 

 smaller the tank, the greater the number of 

 costly trips that must be made. 



Pipelines 



Metal pipelines have been used in the maple 

 sugar grove for 50 years or more. The early 

 metal pipe carried the sap over almost impassa- 

 ble terrain, from one sugar grove to another or 

 to the evaporator house (figs. 41 and 42). Metal 

 or wooden troughs have also been used as 

 "pipelines." 



All these pipelines, whether metal pipe or 

 metal or wooden troughs, had one serious draw- 



