Single longitudinal valve ready to use hose end sprayer

A sprayer head assembly comprises a chemical passage, a carrier fluid passage, and a housing that has an outer surface and an inner surface, which defines a valve chamber configured to be in communication with the chemical and carrier fluid passages. A valve is moveably positioned within the valve chamber between at least a first position, a second position and a third position. The valve defines a first passage, a second passage and a chemical inlet passage that is in communication with the second passage. The valve is configured such that, in the first position, the valve blocks the chemical and carrier fluid passages, in the second position, the first passage is configured to be in communication with the carrier fluid passage while the valve blocks the chemical fluid passage, and in the third position, the second passage is configured to be in communication with the carrier fluid passage and the chemical inlet passage is configured to be in communication with the chemical passage.