The outer coating of the hose should also resist chemical action because spray may occasionally contact it. Liquid pressure varies at different points on the sprayer. Select hoses strong enough to handle the chemicals at the required pressure. Also consider hose construction, composition, and size. Choose hoses rated for higher capacity than the expected operating pressure to provide a margin of safety and to avoid bursting from pressure surges.
Peak pressures much higher than average operating pressures are common.
These peak pressures usually occur when the spray boom is shut off. It is extremely important that the hoses and fittings are in good condition to prevent a possible break and the operator's being covered with chemicals. Because suction hoses are not pressurized, they do not burst. But they collapse if the inlet plugs. If spray pressure cannot be maintained despite all efforts, flow may be restricted.