US Patent 7363938 Constant flow valve assembly

A dual valve assembly includes two regulating valves. Each valve includes an outer housing comprised of a cap joined to a base. The housing is internally subdivided by a barrier wall into a head section and a base section, the latter being further subdivided by a modulating assembly into a fluid chamber and a spring chamber. An inlet and a 90° outlet in the cap communicate with the fluid chamber. Fluid at a variable pressure is admitted into the fluid chamber via the inlet, with the modulating assembly serving to maintain the fluid exiting the fluid chamber via the outlet at a substantially constant pressure. A smaller one of the valves has its base nested within the spring chamber of the other larger valve.