Abstract: A surge arrester comprising a porcelain body, top and bottom pieces. The porcelain body is hollow and contains gap assemblies in series with negative temperature coefficient resistance blocks. The entire column is resiliently mounted so as to center the assembly. The top terminal of the surge arrester has a solid plate and a dished metal diaphragm which will rupture under predetermined conditions. The diaphragm is in communication with a passageway cast in the top cast metal end piece. Similarly the bottom end piece is in electrical connection with the gap assemblies and negative temperature coefficient resistance blocks and also has cast therein a gas passageway which is in communication with another dished metal diaphragm.This is all arranged so that the gases may freely exit without forming a dam in the passageways thereby appreciably decreasing the probability of violent rupture of the surge arrester body during the passage of power fault current.