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Water Safety & Flow Control



Domestic Potable Water Expansion Tanks

Lead Free* Models Available



3/4, 1 in. (20, 25mm)


Series DET Domestic Potable Water Expansion Tanks are used on gas, oil, or electric, direct-fired, residential water heater and hot water storage tank applications to absorb the increased volume of water created by thermal expansion. It also maintains balanced pressure throughout the water supply system by keeping system pressure below the T&P relief valve setting. It is a pre-pressurized, field-adjustable steel tank with an FDA-approved Butyl rubber diaphragm, and brass 3/4 in. (20mm) inlet connection (Model DET-35-M1 has a stainless steel 1 in. inlet connection). An expansion membrane prevents air-to-water contact in the tank ensuring a long system life. IAMPO listed and ANSI/NSF 61 certified. Free-standing or in-line models available. Maximum Pressure: 150psi (10 bar).

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Disclaimer: Watts product dimensions in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements, please contact Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials without prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

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*The wetted surface of this product contacted by consumable water contains less than 0.25% of lead by weight.

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