Abstract: A method of testing a relief or safety valve of the type which includes a valve member, urged into engagement with a seat by a spring arrangement and an adjustment member by means of which the urging force exerted on the valve member by the spring arrangement can be adjusted, the method including the steps of applying a force to an end of the spring arrangement where the latter is operatively connected to the adjustment member, in a manner to continue to urge the valve member into engagement with the seat, and measuring the force thus applied at the moment when said force is just sufficient to disengage the operative connection between the spring arrangement and the adjustment member. The invention also relates to a method of setting a relief or safety valve and to a valve suitable for use in the method of testing and setting.