Locomotive muffled "pop" safety valve, sectioned, patented by G.Crosby between 1875 and 1905. Locomotive muffled "pop" safety valve 1875-1905
Safety valve, Ross 'Pop' valve, brass cylinder sectioned to show internal spring. Ross "Pop" safety valve
Safety Valve, Hackworth's multi-leaf spring type, small, 1818-1838. Multi-leaf spring safety valve 1818-1838
