A valve assembly may include a main housing and first and second electro-statically actuated valves. The main housing may define at least three chambers, with a first chamber configured to be coupled to a high pressure supply port, a second chamber configured to be coupled to an output port, and a third chamber configured to be coupled to a low pressure exhaust port. The first electro-statically actuated valve may be provided between the first and second chambers, and the first electro-statically actuated valve may allow or substantially block fluid communication between the first chamber and the second chamber responsive to a first electrical signal. The second electro-statically actuated valve may be provided between the second and third chambers, and the second electro-statically actuated valve may allow or substantially block fluid communication between the second chamber and the third chamber responsive to a second electrical signal. Related methods are also discussed.