Taken from the Online Editions of the UPC & UMC Answers & Analysis
SUBJECT: Laboratory Faucet Backflow Preventers
SECTION: 603.3.11, Table 603.2, 603.5.7 (2021 UPC)
Question:
1. If a Laboratory Faucet has a serrated nozzle and an ASSE 1035 compliant vacuum breaker, does it still need to have an air gap between the end of the nozzle and the flood level rim of the sink fixture?
2: If an air gap is required, is the minimum gap one inch? If the required air gap is not one inch, what is the minimum gap?
3: Does 603.5.7 apply to Laboratory Faucets with nozzle outlet?
Answer:
1: Yes. An ASSE 1035 laboratory faucet backflow preventer consists of two independently acting check valves with a means for automatically venting to the atmosphere between the check valves. An air gap, as specified in Table 603.3.1 of the 2021 Uniform Plumbing Code (UPC), would be required to prevent the possibility of the atmospheric port* on the ASSE 1035 device from being submerged in contaminated wastewater.
2: The air gap would have to meet the requirements found in Table 603.3.1.
3: No. Section 603.5.7 applies to outlets with hose connections, such as freeze-less yard and wall hydrants and hose bibbs.
*603.4.9 Prohibited Locations. Backflow prevention devices with atmospheric vents or ports shall not be installed in pits, underground, or submerged locations. Backflow preventers shall not be located in an area containing fumes that are toxic, poisonous, or corrosive.
SUBJECT: Temperature Limitation, Shower and Tub-Shower Control Valves
SECTION: 406.3.2 (4) (2021 UPC)
Question:
1: Why is this limited to a water heater conforming to ASSE 1084?
2: Why isn’t ASSE 1082, Performance requirements for water heaters with
integral temperature control devices for hot water distribution systems also an option?
Answer: 1. A water heater conforming to ASSE 1084, as found in Section 408.3.2 of the 2021 Uniform Plumbing Code (UPC), is a point of use water heater. Per Section 1.2.1 of ASSE 1084, “This water heater is intended to supply tempered water at point of use in order to reduce the risks of scalding”. These devices limit water temperature to a maximum of 120°F.
Answer:
1: A water heater conforming to ASSE 1084, as found in Section 408.3.2 of the 2021 Uniform Plumbing Code (UPC), is a point of use water heater. Per Section 1.2.1 of ASSE 1084, “This water heater is intended to supply tempered water at point of use in order to reduce the risks of scalding”. These devices limit water temperature to a maximum of 120°F.
2: A water heater listed to ASSE 1082, per Section 1.2 of the standard “is for water heaters that control the outlet temperature to specific limits and are installed within the hot water distribution system but not at point-of-use.” Water heaters listed to this standard limit water temperature to a maximum of 125°F, which exceeds the water temperatures permitted by Sections 407.3, 408.3.2, 409.4 and 410.3 of the 2021 UPC.
SUBJECT: Downdraft Appliance Ventilation
SECTION: 518.1 (2021 UMC)
Question:
1. Does the code address that type II downdraft exhaust system is not allow for non-grease and non-smoke appliance?
2: Can we use type II downdraft exhaust system for this non-smoke and non-grease appliance in our design?
Answer:
1. No. The Uniform Mechanical Code does not address that a Type II downdraft exhaust system for a non grease and a non smoke appliance cannot be used. Section 518.0 does not prohibit Type II downdraft exhaust systems which would serve appliances that produce little or no grease. If the downdraft ventilation system is classified as Type II, provisions of Section 510.1.7 would be applicable to the ductwork.
2: Yes, if the Authority Having Jurisdiction, under provisions of Section 508.1 of the UMC, makes the determination that the hot pot appliances are of Type II and not Type I because grease or smoke is not present, or if the cooking appliance meets UL 710B [Section 508.1(1) requirements] then the ductwork requirements for a Type II exhaust system can be used. The AHJ would take into account the type of food being cooked and specify the amount of grease produced. If the cooking process uses oil or animal protein, grease laden vapors will be produced. The amount of these vapors will
determine if a Type I duct is required. If the downdraft ventilation system is classified as Type I, provisions of Section 510.1.3 would be applicable.
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Last modified: December 20, 2023