What pressure does a properly functioning positive cutoff valve supply to the boom and nozzles when the spray flow is stopped?

A properly functioning positive cutoff valve is designed to prevent the backflow of liquid and ensure that pressure within the system is maintained appropriately when the spray flow is stopped. This means that it does not allow a vacuum or negative pressure to develop in the system, which could lead to operational failures or reduction in efficacy.

When the spray flow is halted, the positive cutoff valve maintains high positive pressure within the boom and nozzles to keep the system ready for immediate re-engagement when needed. This is important for ensuring consistent spray patterns and preventing any clogging or disruption in the flow from the nozzles. The pressure should remain above atmospheric levels, allowing the applicator to effectively manage and control the spraying process without the risk of air infiltrating the system.

In this context, other pressures such as low negative pressure would imply a vacuum that is undesirable for a spray application system, atmospheric pressure could lead to inconsistent flow management, and equalized pressure may not sufficiently address the need for maintaining operational readiness. Thus, recognizing the role of high positive pressure is essential for the effective operation of aerial applicators.