US Patent 7934515 Backflow bonnet and poppet

A prior art backflow bonnet and poppet is replaced by a functionally equivalent new bonnet and poppet. The new bonnet and poppet reduces risk of freeze damage with about a 50% greater strength against pressure. The new bonnet and poppet has only three parts when assembled versus six parts in the prior art. A hollow in the valve plug holds the biasing spring. The bonnet shaft rides in the hollow.