Flexcon PH5 Thermal Expansion Tank 2.1 Gallons – 3/4" Connection

Product Overview

The Flexcon PH5 Thermal Expansion Tank is a premium 2.1-gallon potable water expansion tank designed to protect residential and light commercial plumbing systems from thermal pressure buildup. Built with Flexcon’s advanced diaphragm technology and a rugged 16-gauge cold-rolled steel shell, the PH5 delivers long-lasting performance and reliable system protection for water heaters and closed-loop potable systems.

This model features a 3/4" stainless steel connection, a 100% butyl rubber diaphragm, and an anti-microbial polypropylene lower water chamber to maintain sanitary conditions and resist corrosion. Each tank is factory tested for seam integrity, structural reliability, and pre-charge accuracy, making it a trusted choice for new installations and replacement jobs.

Features & Benefits

• 2.1-gallon thermal expansion tank for potable water heater systems.
• 16-gauge cold-rolled steel tank for long-term durability.
• Appliance-quality exterior paint suitable for indoor or outdoor installation.
• 100% butyl rubber diaphragm for reliable expansion and contraction.
• Anti-microbial copolymer polypropylene lower water chamber for sanitary performance.
• 3/4" stainless steel connection resists corrosion and maintains water quality.
• Brass air valve with O-ring seal for secure, leak-resistant pressurization.
• Factory-tested for high pressure, seam weld integrity, helium leak, and pre-charge.
• Backed by a 5-year manufacturer warranty.

Specifications

• Model: PH5
• Tank Capacity: 2.1 gallons
• Connection Size: 3/4" stainless steel
• Tank Material: 16-gauge cold-rolled steel
• Diaphragm Material: 100% butyl rubber
• Lower Water Chamber: Anti-microbial copolymer polypropylene
• Exterior Finish: Appliance-quality paint
• Air Valve: Brass valve with O-ring seal
• Testing: High pressure, seam weld, helium leak, and final pre-charge check
• Warranty: 5 years
• Typical Applications: Potable water heater thermal expansion control
• Cross References: Amtrol ST-5 & T-5; Bell & Gossett PT-5; Calefactio HGTE-8; Watts PLT-5

Installation Tips

• Verify the PH5 is correctly sized for the water heater and system pressure.
• Install the tank on the cold-water supply line feeding the water heater.
• Set the tank pre-charge to match the building’s static water pressure before installation.
• Use approved thread sealant or Teflon tape on the 3/4" stainless steel connection.
• Mount the tank in a vertical position whenever possible; support if installed horizontally.
• Check for leaks and confirm system pressure after installation.
• Inspect the tank and verify pre-charge annually as part of routine plumbing maintenance.

FAQs

1. What does the Flexcon PH5 thermal expansion tank do?
   It absorbs excess pressure created when water expands as it is heated in a closed plumbing system, helping protect fixtures, valves, and the water heater.
2. Is the PH5 suitable for potable water?
   Yes. The PH5 is designed for potable water systems, with a butyl diaphragm and anti-microbial polypropylene water chamber.
3. Which models does the PH5 replace?
   It is a direct replacement for Amtrol ST-5 & T-5, Bell & Gossett PT-5, Calefactio HGTE-8, and Watts PLT-5 expansion tanks.
4. How often should I check the pre-charge?
   Flexcon recommends checking the air pre-charge at least once a year, or any time system pressure issues are suspected.
5. Can the PH5 be installed outdoors?
   Yes. The appliance-quality paint finish allows for indoor or outdoor installation, provided the tank is protected from physical damage and extreme conditions.

Product Literature:

• Flexcon PH Thermal Expansion Tanks Brochure
• FLEX2PRO PH Consumer Brochure

Submittal Literature

• FLEX2PRO PH Submittal Sheet