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Zilmet ZS8, 2.1 Gallon, Inline Stainless Steel Expansion Tank

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MSRP $556.20

Sale Price $278.10

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SKU#

ZS8

In stock

ZS8

Key Features

• 2.1 Gallon inline expansion tank for domestic heating or central heating system use, helping maintain stable pressure

• 304 stainless steel shell and connection

• Fixed butyl membrane suitable for potable water applications

• 3/4" inch NPTM connection

• Compact design helps avoid sediment trapping and bacterial growth

• Designed for applications where hygiene is important

• Suitable for coastal areas and harsh chemical environments where plain steel can corrode

• Factory precharged at 50 PSI

• Maximum operating pressure of 150 PSI

• Can be installed where a compact footprint matters

• Easy to check during routine system service as part of the normal maintenance process; if service questions come up, refer to the boiler or system manual

• Tank sizing can vary depending on system requirements

• Common expansion tank sizes are often measured in gallons

• Best performance depends on proper installation location

• Make sure the unit is located where it remains accessible

• In systems where conditions require it, periodic draining may be considered as part of maintenance

• Timely replacement helps prevent pressure-related issues by catching water-quality or performance change before it leads to more trouble

• Built to resist premature wear in demanding conditions

• Helps reduce the risk of pressure-related system repair costs

• 5-year limited warranty

Overview

Zilmet has over 50 years of experience manufacturing expansion tanks, producing more than 5 million tanks and 1 million heat exchangers annually with full vertical integration, including its own diaphragms and bladders. The Zilmet ZS8 is a 2.1 Gallon inline stainless steel expansion vessel built for homeowners, contractors, and property managers who need a compact, hygienic tank for potable water and domestic heating system use.

The Zilmet ZS8 features a 304 stainless steel shell and connection and is rated for pressure management and thermal expansion control in closed systems, with capacity sized to match total heating system volume for safer pressure control in boiler and closed-loop heating applications where heated water can expand and increase water pressure. In a central heating system, its purpose is to help stabilize pressure as temperature changes, with the internal air cushion compressing as heated water expands to protect components from stress in domestic heating systems, residential plumbing systems, and potable water installations where controlling pressure spikes, reducing system stress on pipes, and protecting water quality are essential. Expansion tanks absorb excess pressure from thermal expansion and help maintain pressure in heating systems to prevent damage, reduce risk, and support long-term reliability and efficiency. This model is intended for a closed-system type, not an open vessel design.

Zilmet’s compact design uses a fixed butyl membrane and a seamless diaphragm that does not stretch or crease, allowing cleaner operation with no bubbles or corners to trap sediment or air and helping inhibit bacterial growth.

Benefits of Installation at the Highest Point

• Stainless steel construction helps resist corrosion, with key components working together and the sealed design making pressure control more dependable

• Compact design minimizes areas where sediment can collect; a sealed diaphragm keeps air and water separated, with water on one side, and unlike an open tank installed at the highest point of a vented system, this design helps ensure cleaner operation

• Fixed butyl membrane supports potable water use

• Not the open-tank style historically common in the UK

• For exact placement details, refer to the boiler manual or installer guidance

• Factory precharge of 50 PSI

Specifications

More Information
Drawdown @ 40/60 PSI	0.5
Drawdown @ 30/50 PSI	0.7
Discharge Connection	3/4" NPTM
Material	Stainless Steel
Capacity	2.1
Size	7.8" x 10.8"
Source	https://www.zilmetusa.com/
Model #	ZS8
Manufacturer	Zilmet
Shipping Weight	6
Warranty	5 Year Limited

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Product Literature

Zilmet Inox-Pro Stainless Steel Expansion Tank Specifications

(Size: 0.23 MB)

zilmet_nsf61.pdf

(Size: 0.11 MB)

FAQs

What is the capacity of the Zilmet ZS8?

The ZS8 has a 2.1 gallon capacity.

What systems is this tank intended for?

It is intended for domestic heating systems equipped with boilers or heat exchangers.

What materials are used in the tank?

The shell and connection are 304 stainless steel, and the tank uses a fixed butyl membrane.

Is this tank suitable for potable water applications?

Yes. The fixed butyl membrane is specified for potable water applications.

What is the connection size?

The connection is 3/4 inch NPTM.

What is the factory precharge setting?

The factory precharge is 36 PSI.

What are the operating limits?

The maximum operating pressure is 150 PSI and the maximum operating temperature is 210 F.

Is this model suitable for coastal areas?

Yes. It is designed for environments with brackishness or harsh chemicals that corrode plain steel.

Installation Tips

Installation Brief

This inline expansion tank is installed into a domestic heating system using its threaded connection.

Confirm the tank model, capacity, and 3/4 inch NPTM connection match the system requirements.
Install the tank inline at the intended system connection point.
Verify the factory precharge is 36 PSI before placing the system into operation.
Check that all connections are secure after installation.