Abstract: The maintenance method is for a gate valve. The method comprises the steps of closing the gate valve; removing sequentially the hand wheel, the gland flange, the gland and the packing from the stem of the gate valve; mounting a first clamp onto the gate valve to keep the disc of the valve in an obturating position; untying the packing box and sliding it at least partially along the stem. The method further comprises the steps of removing the packing ring from the shouldering of the stem; mounting a second clamp onto the gate valve to keep the disc in the obturating position; removing the first clamp from the stem; sliding and removing the packing box and the packing ring from the stem; inserting a new packing ring along the stem; putting back the packing box along the stem; mounting again the first clamp onto the gate valve; removing the second clamp from the shouldering; and positioning the new packing ring onto the shouldering of the stem.