Abstract: A quick coupler for fluid lines includes a socket body housing a first popper valve; a socket collar mounted around the socket body, and having a plurality of locking lobes; a plug body housing a second poppet valve; and a plug collar mounted around the plug body, with locking slots for receiving the locking lobes, each locking slot having an entry leg and a lateral leg. The socket body may be attached to a first hose and the plug body may be attached to a second hose. When the plug body/collar assembly is urged, under longitudinal force, into engagement with the socket body/collar assembly, the plug body enters a cavity in the socket body, while the poppet valves are forced against each other and thus opened, bringing the hoses into fluid communication. Concurrently, the locking lobes enter corresponding entry legs of the locking slots and come into alignment with the corresponding lateral legs.