June 20, 2024
From the 2024 UPC Illustrated Training Manual, Chapter 4 – PLUMBING FIXTURES AND FIXTURE FITTINGS
419.0 Food Waste Disposers.
419.1 Application. Food waste disposal units shall comply with UL 430. Residential food waste disposers shall also comply with ASSE 1008.
419.2 Drainage Connection. Approved wye or other directional-type branch fittings shall be installed in continuous wastes connecting or receiving the discharge from a food waste disposer. No dishwasher drain shall be connected to a sink tailpiece, continuous waste, or trap on the discharge side of a food waste disposer.
Any type of force or pumped drain unit such as food waste disposers must enter the system through a wye type or a directional fitting (see Figure 419.2a). This will provide a smooth path for the waste rather than a tee connection, which would cause the waste to flow against the back of the receiving pipe and flow both upward and downward because of the force of the pumping action.
DIRECTIONAL FITTING
Dishwasher drains are not permitted to be connected to a sink tailpiece, continuous waste or trap on the discharge side of a food waste disposal unit. This is because of the possibility of the pressured waste from either the disposal or the dishwasher backing up into the other. If a disposal is present, then the dishwasher waste must connect to the disposal inlet supplied with the disposal (see Figure 419.2b).
CORRECT INSTALLATION OF DISHWASHER AND GARBAGE DISPOSAL
From the 2024 UMC Illustrated Training Manual, Chapter 8 – CHIMNEYS AND VENTS
802.7 Single-Wall Metal Pipe. Single-wall metal pipe shall be constructed of galvanized sheet steel not less than 0.0304 of an inch (0.7722 mm) thick or of other approved, noncombustible, corrosion-resistant material. [NFPA 54:12.8.1]
The use of single-wall metal pipe (e.g., stovepipe) as a vent for gas utilization equipment is limited by the code, especially in dwellings, for several reasons, including the following:
1. The surface of the pipe is usually hot enough to burn a person who accidentally contacts the pipe.
2. The high surface temperature can cause overheating of adjacent combustible material.
3. The heat loss from a long length of pipe in a cool area can result in reduced draft and the condensation of water vapor in the flue gases.
The use of single-wall metal pipe as a vent, where permitted in Section 802.7, is limited to Category I appliances. Note that some building codes do not permit single-wall metal chimneys and unlisted metal chimneys inside one- and two family dwellings.
Single-wall metal pipe is a venting material that has limitations due to its inherently higher heat loss than chimneys and gas vents. Figure 802.7 shows the limitations of single-wall gas vents when compared with the characteristics of doublewall vents.
COMPARISON OF DOUBLE-WALL AND SINGLE-WALL GAS VENT CHARACTERISTICS
(This is not to be considered the official position of IAPMO, nor is it an official interpretation of the Codes.)
IAPMO
IAPMO develops and publishes the Uniform Plumbing Code®,the most widely recognized code of practice used by the plumbing industry worldwide; Uniform Mechanical Code®; Uniform Swimming Pool, Spa and Hot Tub Code®; and Uniform Solar Energy, Hydronics and Geothermal Code™ — the only plumbing, mechanical, solar energy and swimming pool codes designated by ANSI as American National Standards — and the Water Efficiency Standard (WE-Stand)™. IAPMO works with government, contractors, labor force, and manufacturers to produce product standards, technical manuals, personnel certification/educational programs and additional resources in order to meet the ever-evolving demands of the industry in protecting public health and safety.
Last modified: June 20, 2024