Fixtures & Water HeatersQuestion 75 of 120
An indirect waste pipe from a commercial ice machine is 1-1/2 inches in diameter and discharges into a floor sink. What is the minimum required air gap?
a.1 inch
b.2 inches
c.3 inches
d.1-1/2 inches
Explanation
The air gap for an indirect waste must be at least twice the effective diameter of the discharge pipe, so 2 times 1-1/2 inches equals 3 inches measured from the pipe outlet to the flood level rim of the receptor. 1 inch is only the absolute minimum air gap for very small pipes. 2 inches and 1-1/2 inches apply the wrong multiplier to the pipe size.
Law Reference: IPC §802.2Practice all 120 questions free — no signup required.
Related questions on this topic
- A 100,000 Btu/h water heater is placed in a closet and will take combustion air from inside the building only. Using the rule of thumb of 50 cubic feet of room volume per 1,000 Btu/h, what minimum volume of communicating space is needed?
- Where an enclosure takes combustion air from an adjacent room through two permanent openings, where must those openings be located?
- A shower compartment is framed 32 inches by 32 inches inside the finished walls. Does it meet the minimum area and minimum dimension requirements for a shower?
- A 3/8 inch indirect waste tube from a beverage dispenser discharges over an open receptor. Applying the air gap rule, what is the required air gap?
- A laundry standpipe for a residential clothes washer is roughed in with the top of the standpipe 14 inches above the trap weir. Is the installation acceptable?
- A showerhead is rated at the maximum allowable flow. A user showers for 8 minutes. Assuming the head flows at its rated maximum, how much water is used?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against Journeyman Plumber Licensing Exam (UPC/IPC-based) · How we review