Commercial ejector vent size is _____ inches, but if the ejector pit is within _____ feet of a 3 in vent stack the vent can be _____ inches.

Commercial ejector vent size is _____ inches, but if the ejector pit is within _____ feet of a 3 in vent stack the vent can be _____ inches.

• A. 3 inches, 15 feet, 1 inch
• B. 2 inches, 15 feet, 3 inches
• C. 4 inches, 50 feet, 1 inch
• D. 3 inches, 25 feet, 2 inches

Answer: (D)

Ejector pits need proper venting so air can enter and traps don’t siphon when the ejector pumps discharge. The standard vent size for a commercial ejector vent is 3 inches. But if the ejector pit is within 25 feet of a 3-inch vent stack, that larger vent can share the venting so the ejector vent itself can be reduced to 2 inches. Beyond 25 feet, you wouldn’t rely on the stack alone, so you’d keep the 3-inch vent. So the correct statement is: 3 inches, within 25 feet, the vent can be 2 inches.

Ejector pits need proper venting so air can enter and traps don’t siphon when the ejector pumps discharge. The standard vent size for a commercial ejector vent is 3 inches. But if the ejector pit is within 25 feet of a 3-inch vent stack, that larger vent can share the venting so the ejector vent itself can be reduced to 2 inches. Beyond 25 feet, you wouldn’t rely on the stack alone, so you’d keep the 3-inch vent. So the correct statement is: 3 inches, within 25 feet, the vent can be 2 inches.