A solenoid operated modular valve, comprising: a valve body including an end face, a side face, an inner bore, an outlet port in the end face that is disposed in fluid communication with the inner bore, an inlet port in the side face that is disposed in fluid communication with the inner bore, and a connection end opposite the end face; a valve member slidingly received in the inner bore of the valve body, wherein the valve member extends along a longitudinal axis and includes a tapered end that has a frustoconical shape; and a solenoid including a solenoid body that is connected to the connection end of the valve body and a coil disposed inside the solenoid body, the solenoid being operable to move the valve member relative to the valve body along the longitudinal axis between an open position and a closed position, characterized in that the valve body includes an O-ring valve seat that is positioned longitudinally between the inner bore and the outlet port, the valve member includes a valve member abutment surface that contacts the O-ring valve seat when the valve member is in the closed position and that is spaced away from the O-ring valve seat when the valve member is in the open position, and the solenoid body extends annularly about the longitudinal axis, the solenoid operated modular valve further comprising a biasing member positioned in the inner bore of the valve body that biases the valve member towards the open position, wherein the solenoid extends between a first end and a second end, wherein the valve body is connected to the first end of the solenoid, and wherein the solenoid includes a pole piece having a pole piece flange positioned longitudinally between the coil and the connection end of the valve body and a cylinder portion that extends from the pole piece flange into the coil from the first end of the solenoid, an end stop that extends into the coil from the second end of the solenoid, and an armature slidingly disposed in the coil between the cylinder portion of the pole piece and the end stop. a valve body including an end face, a side face, an inner bore, an outlet port in the end face that is disposed in fluid communication with the inner bore, an inlet port in the side face that is disposed in fluid communication with the inner bore, and a connection end opposite the end face; a valve member slidingly received in the inner bore of the valve body, wherein the valve member extends along a longitudinal axis and includes a tapered end that has a frustoconical shape; and a solenoid including a solenoid body that is connected to the connection end of the valve body and a coil disposed inside the solenoid body, the solenoid being operable to move the valve member relative to the valve body along the longitudinal axis between an open position and a closed position, characterized in that the valve body includes an O-ring valve seat that is positioned longitudinally between the inner bore and the outlet port, the valve member includes a valve member abutment surface that contacts the O-ring valve seat when the valve member is in the closed position and that is spaced away from the O-ring valve seat when the valve member is in the open position, and the solenoid body extends annularly about the longitudinal axis, the solenoid operated modular valve further comprising a biasing member positioned in the inner bore of the valve body that biases the valve member towards the open position, wherein the solenoid extends between a first end and a second end, wherein the valve body is connected to the first end of the solenoid, and wherein the solenoid includes a pole piece having a pole piece flange positioned longitudinally between the coil and the connection end of the valve body and a cylinder portion that extends from the pole piece flange into the coil from the first end of the solenoid, an end stop that extends into the coil from the second end of the solenoid, and an armature slidingly disposed in the coil between the cylinder portion of the pole piece and the end stop.