The present application relates to valve and actuator assemblies. The valve actuator assemblies may include a capless valve actuating arrangement, include a replaceable passage defining member that includes seal members, include a valve member that is assembled in a valve chamber from an end of the valve body that is opposite an end that a piston is assembled in, and/or include a valve member that may be rotated in a valve body without affecting the ability of the valve member to perform its sealing functions.