Knowing All the Unheard Facts about Unvented cylinders

An unvented cylinder is meant for storing hot water, which is supplied straight from the main water point and warm it with electrical warming rudiments or just with the heat that comes from the boiler. This in turn offers hot water supply of high pressure which has the ability to feed different outlets with hot water of huge quantity.

The unvented cylinders store hot water under comparatively high pressures usually in the 2-3 bar region and in this way supplies water to different outlets which are at a high level like in a lofty place, and at like pressure to the main supply of cold water.  This increase in pressure gives showers of good quality, without any need of pumps.  Due to the services of hot as well as cold water which are made from the mains, cold water tank for storage is not at all needed, keeping all loft place vivid and pipe work to the least.

Materials:

Unvented cylinders are typically made of copper, stainless steels and also of glass lined steel. Each of these materials has its own advantages, and the kind of cylinder which is to be utilized depends on this application. 

ü  Copper is utilized in manufacturing domestic cylinders of water, primarily as it is simple in cutting, bending, folding and braising.

ü  Stainless Steel material is very strong and has the ability of opposing high pressures. It also has resistance to corrosion making it a great life expectancy, but the welds can be sensitive to oxidization from the water which is alkaline.

ü  Glass Lined Steel cylinder has been developed of a steel cylinder which has a small coating of glass which is for giving resistance power to avoid getting corroded.

Danger Involved:

There are basically 2 dangers, which unvented system of cylinder should address.  The first is the over pressurization which is developed due to backpressure, for instance from a mixer valve. The other danger is its overheating. When the unvented cylinders get overheated and reaches 100°C, then without boiling as it does in the vented systems, water continues rising in temperature along with pressure until it cannot any longer sustain the pressure resulting eventually in splits.  During this time, the immediate lessening in pressure resulting from the split causes water in 'flashing' fast into steam. So, the higher the pressure fails the more the steam and the capability of cylinders withstanding high pressure will dramatically fail or may also explode.

Safety Measures:

In preventing this from at all happening, there are few safety requirements which must be performed.  Moreover further protection should be taken in limiting the pressure of incoming water by Pressure Reducing Valve in the mains.

An Expansion Relief Valve must be fitted in allowing water to get discharged while heating up if ever the accommodated expansion fails in correctly operating. Both these valves are mostly connected into one inlet controlling device.  

A Temperature as well as Pressure Relief Valve must be fitted on the cylinder’s top in order to let water get discharged whenever temperature & pressure reaches levels which are unsafe.  The water discharging in this style will be substituted by the incoming cold water mains which can avoid temperatures from store to rise even more.