AVB stands for Advanced Variable Backcheck. It is a cylinder option when ordering a 4111 closer (without an ST) that allows backcheck to start at about 45 degrees instead of the normal 75 degrees...
The valve on the back of a 4041/4040XP closer is a "Back Check Selector Valve" that needs to be turned in on "Parallel Arm" mount applications ONLY. If a 4041/4040XP closer mounted "Top Jamb", or "...
How to: What are the steps to adjust a door closer?Facts: All LCN and FALCON door closers will have 3 regulating valves and a spring adjustment. All closers with a "Delay" feature ...