How come old NH3 tanks do not supply full flow in cold weather?
This is not an uncommon question since many producers really dont understand how NH3 is pushed out of the tank. The tank valves are the major problem with NH3 liquid flow. Many tanks in service are 30 (1973) to 40 (1963) years old. These 1,000 gallon tanks have 1 inch and 1.25 inch top outlet valves. It is impossible to expect more than 17 gallons a minute flow at 60 psi from these old tanks that were initially designed for 4 and 5 shank tool bars. Remember almost all NH3 was applied in this time period with sidedressing tool bars at warm growing season temperatures. In 1978 coolers were adapted to electronic metering systems. The cooler had been proven on early Dempster pumps to deliver NH3 accurately at higher flows. The cooler allowed the tank to push more NH3 out of tank and deliver a liquid state flow to the flowmeter. About this same time fall application of NH3 became a means for fertilizer dealers to move the application period to the fall rather than the narrow window sidedres
