Patent ID: 8616124

Claim:
A pressure-relief valve comprising: a valve body with a passage that can be closed by a moving closure element; an electromagnet that interacts with a moving armature that is in driving connection with the closure element; and, a spring that interacts with the closure element, a bias tension of the spring being changeable by an adjustment element that can be moved manually relative to the valve body the adjustment element comprising a body and an adjustment screw that is screwed into a thread of the body and defines the bias tension of the spring wherein the adjustment screw can be one of fixed and covered permanently on the body of the adjustment element; wherein the electromagnet is mounted detachably on the valve body and, the adjustment element and the valve body being constructed such that a manual change of the bias tension of the spring by way of the adjustment element is possible only when the electromagnet is detached from the valve body and when the electromagnet has been removed from the valve body, a maximum, manually adjustable bias tension of the spring can be pre-defined.