What is a varem pressure tank?

Varem pressure tanks use a butyl bladder that separates the water inside the pressure tank from the tank’s metal surface, thereby eliminating corrosion and rust possibilities. Since the water is also separated from the pressurized air inside the tank, water-logging is eliminated.

What Colour is the expansion vessel?

Expansion Vessel Generally expansion vessels for the CH system are Red in colour and those for ‘potable’ water, i.e. drinking (not that you would normally drink hot water!) are Blue.

How do you determine expansion vessel size?

Expansion vessels are pre-charged with air that pushes down on a diaphragm, in turn, water enters the vessel on the other side of the diaphragm and begins to compress the air….

Should an expansion vessel be full of water?

You are correct. The expansion tank is usually about half full of water and half full of air–by volume. One tank full of air at atmospheric pressure will be about half its volume when pressurized. When in doubt, drain it.

What is an expansion vessel?

Expansion vessels, also known as expansion tanks, can be found in most domestic pressurised heating systems. If you have a combi boiler, you will have an expansion vessel. This vessel contains air and water from the central heating system, and its purpose is to maintain the right level of pressure in the system.

How does a diaphragm water tank work?

Pressure tanks have a diaphragm, also called a bladder, that separates a chamber of air from the water. As the tank fills with water, it compresses the air chamber. When you turn your water on, the compressed air pressurizes the water and pushes it back out of the tank.

What is a white expansion vessel?

White vessel has a bladder. The expansion is contained within the bladder and at no time will the water contact metal surfaces. My experiance has been that fitting such a vessel to ‘hot’ side of a boiler will result in bladder failure.

What is a red expansion vessel?

A red expansion vessel is a small tank used to protect closed (not open to atmospheric pressure) water heating systems and domestic hot water systems from excessive pressure. As water can increase by 4.5% volume when heated from 0-100 °C an Expansion Vessel is a vital part of any sealed heating system.

What size potable expansion vessel do I need?

Potable Expansion Vessel Sizing Guide

What bar should expansion vessel be?

Some important things to consider is the air pressure inside the expansion vessel. It rarely needs to be anything more than 1.5 bar in most domestic properties. Anything more and the water may not expand into the air at the required time and could risk the high pressure relief valve opening or worse.