113021 #87 Automatic Air Vent No. 87,   Automatic Air Vents are designed to vent the accumulation of troublesome air wherever it can be trapped. These non-ferrous automatic air vents are 4-3/4"x2-1/4", 3-3/16"x1-1/2" and 4-1/16"x2-3/16" (height and width), respectively, and are rated for maximum operating temperature of 240ºF at pressures of 150, 35 and 75 PSI, respectively. The No. 87 has a combination of ½" FPT/¾" MPT connection, whereas No's. 67 and 7 have 1/8" MPT, and FPT connections, respectively.