Amtrol ST-12 THERM-X-TROL Expansion Tank, 4.4 Gallon (141N43) at PlumberSurplus.com

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Product Description

Amtrol ST-12 THERM-X-TROL Expansion Tank, 4.4 Gallon (141N43)

What Is Thermal Expansion?

With modern plumbing codes mandating backflow prevention, thermal expansion can cause pressure buildup in domestic water systems. When demand is put upon a potable water system, hot water is drawn from the water heater. Cold water from the supply line enters the water heater to replenish it. The colder water is heated to replace the hot water used. With the installation of a backflow preventer, check valve or pressure reducing valve on the supply line, the water heater and the system piping form a closed plumbing system under pressure. As the water is heated, thermal expansion occurs. Pressure increases until the relief valve opens and the expanded water "spills" from the water heater. This "spillage" results in wasted BTU's and a potential safety hazard for the homeowner.

Closed Potable Hot Water system without THERM-X-TROL

Backflow preventer, pressure reducing valve or meter causes expanded (heated) water to build pressure causing the relief valve to open resulting in:
• Wasted BTU's
• Shortened water heater life
• Wasted municipal water and sewer dollars
• Potential safety hazard for homeowner

The Amtrol THERM-X-TROL ST-12 Expansion Tank is designed to eliminate this problem by providing control of maximum pressures at a level below the relief valve setting. It also provides an additional space in the system to accommodate the increased volume of water created by thermal expansion, returning it to the system when hot water delivery is demanded. Maximum pressure is kept well below the relief valve setting by the THERM-X-TROL, with its pre-charged air cushion that is separated from system water. The relief valve does not open, therefore "spillage" is eliminated.

Closed Potable Hot Water System with THERM-X-TROL

Expanded (heated) water is absorbed by THERM-X-TROL which means:
• Water heater and fixtures are protected
• Eliminates BTU and water waste, saving money and energy
• No dangerous pressure build up in the system
• Relief valves will not operate
• Potential safety hazard reduced

Amtrol THERM-X-TROL ST-12 Expansion Tank Features:
• Brass System Connection (In-Line Models) (Stainless Steel Elbow for Vertical Models)
• Deep Drawn Steel Domes for maximum strength & pressure rating
• Rigid Poly-Propylene Liner for Corrosion Resistant Reservoir
• Butyl diaphragm for long life expectancy tested to over 250,000 cycles
• Diaphragm Hoop Ring mechanically grooved for permanent air-tight seal
• Welded Steel Construction
• Brass Air Charge fitting with Protective Plastic Cap for Corrosion Resistance. Brazed for Strength and Maximum Air-Tight Seal

Amtrol THERM-X-TROL ST-12 Expansion Tank General Usage:
• Office Buildings
• Apartment Buildings
• Dormitories
• Elderly Housing
• Extended Care Facilities
• Condominiums/Large Residential
• Food Service (other than Restaurants)
• Laundromats
• Hospitals
• Other General-Use Hot Water Systems

Amtrol THERM-X-TROL ST-12 Expansion Tank Specifications:
• Model Number - ST-12
• Total Volume (gallons) - 4.4
• Diameter (A) - 11"
• Height (B) - 15"
• System Connection - 3/4" NPT
• Materials: Steel shell, polypropylene liner, butyl diaphragm
• System Connection: ST-5, ST-12 = Brass; ST-25V to ST-210V = Stainless Steel
• Maximum Operating Temperature = 200°F
• Maximum Working Pressure = 150 PSIG
• Factory Precharge = 40 PSIG