The Transland spray valve is one of the most important components of the spray system and must be kept working properly. 
Briefly, the pressurized spray liquid leaves the spray pump to be sprayed through the booms and nozzles.
Through adjustment of the spray valve while spraying, the pilot selects the amount of flow that goes to the boom, The remainder of the flow splits through the valve and returns to the hopper to provide agitation of the spray mixture. When the spray booms are turned off, all of the pump’s output is directed to the hopper for agitation.
Perhaps one of the most important functions of the valve is one that is not obvious. The inside of the valve has a passageway from the boom side of the valve to the hopper return side through a venturi. The chemical passing the venturi creates a “negative pressure” on the boom side of the valve. When not spraying, the suction acts as “suck back” to assist the spray nozzles in making a clean shut off and prevent dripping nozzles. The amount of suck back is adjustable and should be properly adjusted to provide the amount of suction required for proper nozzle orientation. If this passage becomes clogged, the suck back will not work at all.
Want more information? We are here to help. Call Transland at 940.687.1100.