Does expansion vessel go on flow or return?

The Expansion Vessel must be fitted to the Return Side of the Central Heating System and in such a way that there can at no time be an obstruction between the vessel and the system. Some provision for the prevention of air ingress into the vessel must also be made as this will degrade the vessel very quickly.

What is a flow through expansion vessel?

What are flow through expansion vessels? Flow through expansion vessels reduce this risk by using a Flowjet valve to force water through the expansion vessel. The Flowjet valve diverts part of the water flow from the system supply into the vessel.

What pipe does an expansion vessel go on?

The new pipe work needs to connect the return pipe from the boiler to the Expansion vessel. Here we have used 15mm copper pipe (plastic pipe should never be used close to a boiler) and compression fittings. The connector that fits on top of the expansion vessel is a 3/4 inch tap connector.

Where does the expansion vessel go on an unvented cylinder?

It may be mounted to the top of the cylinder, or it could be attached in some other location. With some models, it is actually within the casing of the water heater.

How do you calculate flow rate through a valve?

The volume flow rate for liquids can be calculated by multiplying the fluid velocity times the flow area. Thus, Cv is numerically equal to the number of U.S. gallons of water at 60°F that will flow through the valve in one minute when the pressure differential across the valve is one pound per square inch.

How does an anti Legionella valve work?

The Reliance Anti-legionella valve converts a standard single connection expansion vessel into a ‘flow through’ type. It does this by diverting a portion of the flow into the vessel so that the water content is continually renewed to prevent water stagnation, which can cause to Legionella growth.

What pressure should my 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.

Where should an expansion tank be installed?

An expansion tank is generally installed directly above the water heater by means of a tee-fitting installed in the cold water delivery pipe. The expansion tank is usually installed horizontally, though it is acceptable to install it vertically if it is necessary because of space limitations.