According to the International Plumbing Code and most state codes, the temperature of water entering a sewer system must not exceed 140°F. Discharges or “draw water” hotter than 140°F can compromise the integrity of drain lines, causing leaks and even total failure.
Boilers, humidifiers, autoclaves/sterilizers, and commercial-kitchen equipment produce drain water exceeding 140°F. Many facilities managers and plumbing professionals either are unaware of this or do nothing about it, putting personnel and property at great risk and exposing themselves to the possibility of a failed inspection, fine, and/or business interruption/delay.
Last year, for instance, the owner of a chain of coffee shops was preparing to open a brand-new property in New York. The finishing design touches were complete, staff was hired, inventory was ordered, and marketing materials were created; all that was left was the plumbing inspector making his rounds. The inspector discovered water from the shop’s espresso machine was entering the drain lines at 148°F, 8°F above the specified limit. By the time corrections were made and the property was re-inspected, two weeks had passed. To the owner, the delay was time-consuming and costly.
Cooling drain water to below 140°F is relatively easy and can be accomplished by several means. One involves a valve opening and closing an attached cold-water line. There are two types of valves:
- Electrically actuated. An electrically actuated valve is controlled by an electric current through a solenoid. A temperature switch/thermostat makes or breaks the electrical circuit, signaling the solenoid to open or close the valve.
- Mechanically actuated. Mechanically actuated valves do not require an external power source. A thermal actuator senses when hot drain water is present. When hot water heats the actuator, the valve opens, releasing cold water. As drain-water temperature decreases, the valve starts to close. This modulating feature conserves water compared with a solenoid valve, which is either open or closed.
Code-compliant drain discharges are necessary for effective operations and management. Temperature-control valves are a cost-effective, efficient, and painless way to ensure the safety of your employees, the integrity of your plumbing system, and that your property passes inspection. By adding a temperature-control valve to your commercial equipment, you can make sure you and your staff do not end up in hot water.
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Vice president of engineering for Therm-Omega-Tech Inc., designer and manufacturer of self-actuating temperature-control valves, Nick Tallos has more than 40 years of engineering experience. He holds a bachelor’s degree in mechanical engineering from Villanova University and is a member of the International Association of Plumbing and Mechanical Officials, ASME, and The International Society of Automation.