Abstract: A pressure relief device mounts to heat exchange coils having fluid flowing therethrough. A base has an orifice formed therethrough extending through an orifice in the coil to the interior of the coil. A cover attaches to the base with bolts or other attachment means. A diaphragm strip inserts between the cover and the base to close off the orifice in the base. An o-ring or other gasket may also be utilized to seal the structure. When a rupture through the diaphragm occurs due to pressure buildup, the diaphragm strip may be advanced to reclose the orifice.