Backflow preventers from IMT offer many possibilities
Author: Detlef Wehrs – Sales Director Germany, IMT ARMATUREN AG
Backflow preventers from IMT offer many possibilities
Author: Detlef Wehrs – Sales Director Germany, IMT ARMATUREN AG
Before the cold season, maintenance work on heating systems begins. This is just the right time to also subject the system separator to a thorough check – if it is installed at all. The Swiss company IMT offers application-specific solutions that are easily installed or can be exchanged with existing solutions.
Since August 2011, the European Standard EN 1717 in force that regulates drinking water protection.
The national remaining standard DIN 1988 Part 4, which had previously still been applied in parallel, was repealed at the above-mentioned date. A hose connection between the drinking water network and the heating system without a backflow preventer is therefore – even if only used temporarily – no longer permitted.
Central heating water not suitable as drinking water
This simple insight prompted the EU to tighten the requirements for safety devices to prevent drinking water contamination caused by backflow through standard EN 1717. Heating systems, which are generally filled with drinking water, often require retrofitting in existing buildings through the new installation or replacement of system separators that are no longer approved.
The European standard classifies liquids into five categories with different types of hazard. Heating water without additives is assigned to hazard type 3 (posing a health hazard due to substances of low toxicity), while heating water with additives, e.g. corrosion inhibitors or antifreeze, falls into hazard type 4, which implies a very high health risk for humans.
Depending on the hazard classes, different types of backflow preventers are required for use.
Type BA backflow preventers allow protection against non-potable water up to hazard class 4, the highest hazard class that may be protected against by a fitting.
A controllable three-chamber system with two non-return valves connected in series and a drain valve prevents non-drinking water from flowing back into the drinking water installation.
Compliant filling in no time at all
If heating systems in existing buildings are increasingly serviced by the plumbing, heating and sanitation trade in the coming months, a look at the filling device must not be missed.
In many boiler rooms, the installer will find hose connections between the heating system and the drinking water network that are no longer approved. These can be quickly and easily converted into a standards-compliant installation using a small, compact type BA art. 309V backflow preventer from IMT. The backflow preventer is fitted to the existing draw-off point using a 3/4“ brass screw connection, and the existing hose is then attached to the end of it. Done.
The DVGW-approved BA type 309V backflow preventer can be installed indoors and outdoors.
Would you like a little bit more?
When professionally filling heating systems, backflow preventers with integrated refilling valves are becoming increasingly popular. The built-in pressure reducer keeps the pressure in the heating system constant. If the pressure drops due to minor leaks or water vapour diffusion, water is automatically topped up from the drinking water supply until the specified pressure is reached.
IMT offers the system separator BA Art. 305K for this application, which can be installed in an existing or newly constructed pipe with can be integrated with 1/2“ or 3/4“ screw connections.
If particularly hard water is present in the supply area – i.e. high concentrations of calcium and magnesium ions – the water should be treated with softening cartridges before filling the heating system. IMT offers a heating filling unit complete with the type BA refilling combination, item no. 305K, for this purpose. This has a capacity of 4000 °d x litres and also features Connection thread in ½“ – ¾“.
Quickly forgotten
Many end consumers block out the fact that there is also a risk from backflowing and backing-up water in outdoor areas.
Standpipes and external draw-off taps must be fitted with safety devices in the same way as the connection between heating systems and the drinking water installation.
The BA backflow preventer, Art. 302 offers excellent properties for this purpose. It is reasonably priced, suitable for use even in hazard class 4 areas and very compact in its dimensions. This makes it easy to secure garden watering points or public taps offered to market or funfair operators.
Opportunities for the trades sector
Many homeowners are not properly informed about the sensitive subject of Drinking water hygiene at the interface with the heating system or the water supply of other domestic areas. This is primarily always about protecting users from health impairments.
The plumbing, heating and sanitary trade is required to advise private individuals professionally and to draw attention to non-compliant installations. During the annual maintenance of heating systems and backflow preventers – which are often forgotten – there is a good opportunity to assess the protection status of the drinking water network and propose measures for a compliant installation. Technically, retrofitting for a permanent connection to the heating system is completely unproblematic in most cases.