Double valve with anti-tiedown capability

摘要

A control valve system has two valve trains (602, 604) each of which has a series of valves (528, 532; 530, 534) which dynamically move between a deactuated position and an actuated position. An inlet (514) of the valve system is connected to an outlet (516) of the valve system when all of the valves are actuated and the outlet (516) of the valve system is connected to an exhaust (518) when all of the valves are deactuated. Each valve train (602, 604) includes a solenoid valve (536, 538) which when actuated moves the remaining valve members to their actuated position. The various valves (528, 532; 530, 534) of each valve train (602, 604) are interconnected with the valves (530, 534; 528, 532) of the other valve train such that actuation of all of the valves in a substantially simultaneous manner will connect the inlet (514) of the valve system to the outlet (516) of the valve system and deactuation of all of the valves in a substantially simultaneous manner will connect the outlet to the exhaust. The valve system monitors the dynamic movement of the valve members during its operation and will move to a locked out condition when any valve (602, 604) is in a deactuated position and when the other valve (602, 604) is in an actuated position. In the locked out condition, the outlet (516) of the valve system is connected to the exhaust (518). The valve system will remain in this locked out condition until a reset operation is performed. During a reset operation, the valve system can not actuate one of the valve trains (602, 604) because one of the valve trains (602, 604) is depressurized during the reset operation.