![File:Double-beat valve, from beam engine cylinder (New Catechism of the Steam Engine, 1904).jpg - Wikimedia Commons File:Double-beat valve, from beam engine cylinder (New Catechism of the Steam Engine, 1904).jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/5/59/Double-beat_valve%2C_from_beam_engine_cylinder_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg)
File:Double-beat valve, from beam engine cylinder (New Catechism of the Steam Engine, 1904).jpg - Wikimedia Commons
![Railway mechanical engineer . Fig. 12- □Lockyer Double Beat Valve Showing Assembled Valveand Separate Parts shop which is of sufticient capacity to more than take careof the needs of the road. Railway mechanical engineer . Fig. 12- □Lockyer Double Beat Valve Showing Assembled Valveand Separate Parts shop which is of sufticient capacity to more than take careof the needs of the road.](https://c8.alamy.com/comp/2CGXHC0/railway-mechanical-engineer-fig-12-lockyer-double-beat-valve-showing-assembled-valveand-separate-parts-shop-which-is-of-sufticient-capacity-to-more-than-take-careof-the-needs-of-the-road-special-attachmentsamong-the-attachments-to-this-locomotive-may-be-men-tioned-the-lockyer-double-beat-throttle-valve-designedby-n-c-lockyer-the-works-manager-at-darlington-thisis-shown-in-figs-12-and-13-the-purpose-of-this-valveis-to-obtain-a-more-nearly-balanced-valve-than-is-possiblewith-the-ordinary-construction-of-double-seated-valve-inorder-to-do-this-it-has-been-necessary-to-split-the-val-2CGXHC0.jpg)
Railway mechanical engineer . Fig. 12- □Lockyer Double Beat Valve Showing Assembled Valveand Separate Parts shop which is of sufticient capacity to more than take careof the needs of the road.
![File:Double-beat valve, from beam engine cylinder (New Catechism of the Steam Engine, 1904).jpg - Wikimedia Commons File:Double-beat valve, from beam engine cylinder (New Catechism of the Steam Engine, 1904).jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Beam_engine_cylinder_with_double-beat_valves_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg/220px-Beam_engine_cylinder_with_double-beat_valves_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg)