Pressure control unit

摘要

Pressure control devices with a valve connected between an inlet chamber and an outlet chamber and a non-return valve operating as a by-pass are known. The non-return valve opens due to a reduction in pressure in the inlet chamber relative to the pressure in the outlet chamber against a closing force. This type of known pressure control devices are very expensive to manufacture and are not safe against failure and great erosion. According to the present invention a single arrangement providing the valve and the non-return valve comprises a tappet with a valve body fixed thereto to provide the operation of both valves. The valve body is essentially cylindrical and elastic and its outer surface is spaced from the inner surface of the outlet chamber. The outer surface of the valve body is armored in such a way that a deformation in the radial direction toward the inner surface of the outlet chamber is avoided.