Potable Expansion Vessels: What You Need to Know

Potable Expansion Vessels: What You Need to Know

When it comes to maintaining a safe and efficient water system, one essential component often overlooked is the potable water expansion vessel. These vessels play a vital role in ensuring that your system runs smoothly, prevents damage, and protects both property and users.

What is a Potable Expansion Vessel?

A potable expansion vessel is a specially designed unit that absorbs excess pressure in a potable (drinking water) system. As water is heated, it expands - and without a safety mechanism in place, this increased pressure can strain pipes, joints, and appliances.

Unlike standard heating expansion vessels, a potable water expansion vessel is manufactured from materials that are safe for contact with drinking water. They include food-grade linings and membranes to maintain water quality while preventing contamination. Also, potable vessels use an internal bladder that keeps water isolated, whereas heating vessels use a crimped-in membrane, allowing water to contact the steel body.

Why Do You Need a Potable Water Expansion Vessel?

There are several important reasons why installing a potable expansion vessel is crucial:

  • Protects your plumbing system: Prevents pipework and fittings from being damaged due to excess pressure.
  • Ensures water safety: Designed for use with potable water, these vessels maintain water purity.
  • Extends system lifespan: Reduces stress on appliances like water heaters, prolonging their efficiency.
  • Prevents leaks: Helps avoid costly water damage caused by uncontrolled pressure build-up.

Where Are Potable Water Expansion Vessels Used?

A potable water expansion vessel is commonly used in:

  • Domestic hot water systems
  • Unvented water heaters
  • Commercial and industrial potable water installations

Whenever water is heated and consumed for drinking, cooking, or washing, a potable expansion vessel ensures both performance and safety.

Choosing the Right Potable Water Expansion Vessel

When selecting a potable expansion vessel, consider:

  • Capacity: Ensure the vessel is correctly sized for your system.
  • Compliance: Look for models that meet Regulation 4 approvals – for example WRAS, KIWA Reg 4, NSF Reg 4.
  • Quality materials: Opt for vessels with Regulation 4-grade linings suitable for drinking water.
  • Application: Make sure you are installing the best potable expansion vessel for your application – do you need a standard potable vessel, or would a flow-through vessel be more appropriate for the system?
  • Installation: Ensure vessels are always fitted to the manufacturer’s instructions to ensure they work as intended – paying note to vessel orientation and avoiding ‘dead legs’ where possible.
  • Maintenance: Check whether the membrane can be replaced for longer service life.

Why Choose Altecnic Potable Expansion Vessels?

Altecnic offers a comprehensive, versatile range of potable water expansion vessels that prioritise water safety, system protection, and long-term performance.

Key Features of the Altecnic Range

  • Available in vertical, horizontal, and flow-through designs to suit different installation needs.
  • Available in capacities from 0.5 to 1000 litres.
  • Fully compliant with the PED 2014/68/EU, and BS EN 13831, ensuring industry-standard safety and reliability.
  • Models available built with nitrogen pre-charge, which enhances bladder life and prevents internal corrosion.
  • Coated internally to avoid corrosion; many models include replaceable bladders for easy maintenance.
  • All Reflex, Nitrogen filled models carry a 5-year warranty, reflecting Altecnic’s confidence in their durability.

 

Click here to order potable vessel calculators

Explore our product range: https://www.altecnic.co.uk/domestic/expansion-vessels/potable-vessels

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