Charman Inc.
Mini 304 Stainless Steel Expansion Tank
- SKU:
- 420003
- Availability:
- Usually in Stock – Ships Quickly
- Weight:
- 1.00 LBS
Description
Mini 304 Stainless Steel Expansion Tank
Charman Manufacturing Mini 304 Stainless Steel Expansion Tank provides a compact solution for controlling thermal expansion in small plumbing and hydronic systems where installation space is limited. Constructed from durable 304 stainless steel, this compact expansion tank is designed for dependable service in residential water-heater, combi-boiler, and mechanical-room applications.
Factory pre-charged to 50 PSI, this tank is engineered for systems operating at pressures up to 145 PSI and temperatures up to 210°F. Its compact configuration makes it especially useful where a traditional full-size expansion tank may be difficult to install.
Product Highlights
- Compact thermal expansion tank for space-restricted installations
- Durable 304 stainless steel construction
- Corrosion-resistant design for long service life
- Factory pre-charged to 50 PSI
- Maximum working pressure of 145 PSI
- Maximum operating temperature of 210°F
- Rated for compact systems and water heaters up to 2 gallons
- Ideal for residential water heaters and combi-boilers
- Well suited for compact mechanical closets and equipment installations
- Manufacturer item number 420003
Technical Specifications
| Manufacturer | Charman Manufacturing |
|---|---|
| Manufacturer Item Number | 420003 |
| Product Type | Mini Thermal Expansion Tank |
| Material | 304 Stainless Steel |
| Factory Pre-Charge | 50 PSI |
| Maximum Working Pressure | 145 PSI |
| Maximum Operating Temperature | 210°F |
| System / Water Heater Rating | Up to 2 Gallons |
| Primary Applications | Residential Water Heaters, Combi-Boilers, Compact Mechanical Systems and Thermal Expansion Control |
| Construction | Compact Stainless Steel Tank |
What Is a Mini Expansion Tank?
A thermal expansion tank is designed to help accommodate increases in water volume that occur as water is heated inside a closed plumbing system. When water temperature rises, the water expands. In systems where check valves, pressure-reducing valves, backflow preventers, or other components prevent expanded water from moving back into the supply system, system pressure can increase.
A properly selected expansion tank provides a controlled location for this additional water volume, helping reduce unnecessary pressure fluctuations within the plumbing system.
The Charman Mini Expansion Tank is specifically designed for compact applications where space is limited and a conventional larger expansion tank may not be practical.
Why Choose a Stainless Steel Mini Expansion Tank?
Compact Installation
- Designed for tight plumbing spaces
- Ideal for compact mechanical closets
- Well suited for point-of-use equipment
- Reduces the space required compared with many conventional expansion tanks
- Useful for installations where equipment clearance is limited
304 Stainless Steel Construction
- Corrosion-resistant stainless steel construction
- Designed for long-term plumbing service
- Suitable for demanding mechanical environments
- Clean, professional stainless-steel appearance
- Built for reliable thermal expansion control
Performance Features
50 PSI Pre-Charge
The tank is factory pre-charged to 50 PSI to provide a consistent starting pressure for compatible plumbing-system installations.
145 PSI Maximum Pressure
Designed to handle system pressures up to 145 PSI when properly selected, installed, and applied according to project requirements.
210°F Maximum Temperature
Rated for operating temperatures up to 210°F, making it suitable for many hot-water and compact mechanical-system applications.
Common Applications
Residential Water Heating
- Small residential water heaters
- Point-of-use water heaters
- Compact hot-water systems
- Closed domestic water systems
- Thermal expansion control near water-heating equipment
Mechanical & Boiler Applications
- Combi-boilers
- Compact mechanical closets
- Small equipment rooms
- Space-restricted plumbing installations
- Mechanical systems requiring compact thermal expansion control
Understanding Thermal Expansion
When water is heated, its volume increases. In an open plumbing system, some of this expanded water may be able to move back toward the water supply. In a closed system, however, devices such as backflow preventers, check valves, or pressure-reducing valves may prevent this movement.
Without adequate expansion capacity, this increase in water volume can cause pressure fluctuations inside the plumbing system. A properly sized and installed expansion tank absorbs a portion of this expanded water volume and helps stabilize system pressure.
Expansion-tank sizing should always be based on the specific water-heater capacity, supply pressure, operating temperature, and system configuration.
Where a Mini Expansion Tank Makes Sense
- Installations where a traditional expansion tank is physically too large
- Point-of-use water heaters located under counters or inside cabinets
- Compact combi-boiler installations
- Mechanical closets with limited wall or ceiling clearance
- Retrofit applications where available mounting space is restricted
- Small closed plumbing systems requiring thermal expansion control
Installation & Sizing Guidance
- Confirm that the tank is properly sized for the water-heater or plumbing-system capacity before installation.
- Verify the system's static water pressure before placing the expansion tank into service.
- Confirm that the factory pre-charge is appropriate for the plumbing system and installation requirements.
- Do not exceed the manufacturer's maximum working pressure of 145 PSI.
- Do not exceed the manufacturer's maximum operating temperature of 210°F.
- Install the tank in accordance with applicable plumbing codes and manufacturer recommendations.
- Confirm that all piping, fittings, valves, and connection components are suitable for the system pressure and temperature.
- Support the tank and connected piping as required by the installation.
- Inspect the tank and connection points for leaks after installation.
- Installation should be completed by qualified personnel familiar with thermal expansion systems.
Product Selection Considerations
System Capacity
This mini expansion tank is rated for compact applications and water heaters up to 2 gallons. Always confirm that the tank provides sufficient expansion capacity for the specific system before ordering.
System Pressure
Expansion-tank performance depends on proper system pressure and pre-charge conditions. Verify the incoming water pressure and system requirements before installation.
Need Help Selecting an Expansion Tank?
Our industrial PVF specialists can help review your water-heater size, system pressure, temperature requirements, application, and available installation space before you order.
Frequently Asked Questions
What is the Charman Mini Expansion Tank used for?
It is designed to help control thermal expansion in compact closed plumbing systems, including small residential water-heater and combi-boiler installations.
What material is the tank made from?
The tank is manufactured from durable 304 stainless steel for corrosion resistance and long-term service.
What is the factory pre-charge pressure?
The Charman Mini Expansion Tank is factory pre-charged to 50 PSI.
What is the maximum working pressure?
The manufacturer's published maximum working pressure is 145 PSI.
What is the maximum operating temperature?
The tank is rated for operating temperatures up to 210°F.
What size water heater is this tank intended for?
The manufacturer identifies this mini expansion tank for compact systems and water-heater applications rated up to 2 gallons.
Can this expansion tank be used with a combi-boiler?
Yes. Charman identifies combi-boilers as one of the intended applications for this compact expansion tank. Confirm system sizing, pressure, temperature, and installation requirements before use.
Why would I use a mini expansion tank instead of a larger expansion tank?
A mini expansion tank is useful when installation space is limited, such as inside compact mechanical closets, near point-of-use water heaters, or around tightly installed plumbing equipment.
Does an expansion tank reduce pressure in the plumbing system?
An expansion tank provides additional volume for heated water to expand into and can help reduce pressure fluctuations caused by thermal expansion. It does not replace a pressure-reducing valve or other pressure-control equipment when those components are required.
Should the tank pre-charge match the system pressure?
Expansion-tank pre-charge requirements depend on the plumbing system and manufacturer installation instructions. The tank is supplied factory pre-charged to 50 PSI, but system conditions should be verified before installation.
Who should install this expansion tank?
Installation should be performed by qualified plumbing or mechanical personnel familiar with thermal expansion, system pressure, and applicable plumbing codes.
Important Ordering Notes
- Manufacturer item number: 420003.
- Product is manufactured from 304 stainless steel.
- Factory pre-charge is 50 PSI.
- Maximum working pressure is 145 PSI.
- Maximum operating temperature is 210°F.
- Manufacturer identifies the product for compact systems and water heaters up to 2 gallons.
- Confirm expansion-tank sizing for the specific water-heater capacity and plumbing system before ordering.
- Verify system pressure, temperature, and installation requirements before installation.
- Confirm applicable plumbing-code requirements for the installation location.
- Connection size and physical dimensions should be confirmed from current manufacturer documentation if required for the project.
- Installation should be completed by qualified personnel.
