PRESSURE LIMITING DEVICE

摘要

Device for limiting the pressure of a fluid in a high-pressure circuit (9), comprising a valve (2) having a communicating orifice (8) between said upstream high-pressure circuit (9) and a downstream low-pressure discharge circuit, said orifice (8) having a downstream seat (11) for a mobile close-off element (5) held in contact with said seat (11) by a return spring (4) until a predetermined pressure threshold P₂ is exceeded in the high-pressure circuit (9). The close-off element (5) comprises a portion (6) situated in the immediate continuation of its end in contact with the seat (11), which has a cross section greater than the fluid communication orifice (8) and which slides in a housing (7) in the body of the valve (2) with minimal clearance to prevent leaks between the high-pressure (9) and low-pressure circuits until said sliding portion (6) is expelled from the housing (7) as a result of an increase in pressure. Said sliding portion (6) of the close-off element (5) is also held in its axial position and with radial play relative to a push member (3), on the opposite face of which the return spring (4) bears and which slides in a jacket (1) to which the valve (2) body is fixed. The device is equipped, downstream of the close-off element (5), with at least one fluid escape orifice (10, 10') to permit the evacuation of the fluid when the sliding portion (6) of the close-off element is outside of the housing (7).