ATEX Non-Return Valve – Uses, Benefits and Applications
Do I need an ATEX Non-Return Valve?
If you are operating in an explosive atmosphere, then you should consider installing an ATEX Non-Return Valve. The Health and Safety Executive (HSE) describes explosive atmospheres as “atmospheres where there is a mixture of dangerous substances in the forms of gases, vapours, mist or dust. In the event of ignition, combustion would spread to the entire unburned mixture”.
Why do I need a Non-Return Valve?
The benefits of ATEX non-return valves is that, in the event of an explosion, they will reduce the downtime of production and decrease the cost of replacement parts. As well as protecting your employees in the workshop. This is because the explosion will be isolated to a specific part of the system. So other areas of the same ductwork system will be protected. This is vital if you are running large scale operations where you are trying to avoid downtime as much as possible.
What happens if I do not have one?
The worst-case scenario is that an explosion occurs in your system and you do not have an ATEX Non-return valve installed. Here are the consequences:
- A costly clean-up job:
You will have to remove and replace all the affected areas of the system. This can be expensive depending on how large of an operation you are dealing with. This will cost you for all the replacement parts and the labour to get the new parts fitted.
- Downtime of production:
Since the explosion occurred, your system is no longer operational. The most important task at this point is to get back to being fully operational. For the time it takes to source the materials, get them delivered on site, get them fitted and tested – how much money are you losing during this time?
- Injured employees
When an explosion happens in a dust collector, the shock waves and flames are immediately moving through the system searching for its way out. One way out is through the extraction point, where most of the time employees are working. The power created by this explosion can be fatal for people and therefore companies often try to make sure their employees will be protected by such event. An ATEX non-return valve is a perfect way to make sure the explosion gets blocked and therefore will not be able to find its way to the extraction point.
- Economically suitable solution for security against an explosion
- Completely mechanical requiring practically no maintenance
- NO power consumption
- Low pressure loss
- High pressure resistance
How are they going to protect my system during an explosion?
During operation, the valve will remain open due to the normal airflow. In the event of an explosion, the airflow in the exhaust pipe drops due to the pressure of the explosion – this causes the valve to close by its own weight, therefore blocking the ducting.
Ensure that you are installing a valve in conjunction with the correct explosion protection on the filter unit
The pressure wave of the explosion, as well as the flame that arises, pushes in the opposite direction of the normal airflow. This then pushes the flap against the frame of the device, which in turn blocks the rest of the ducting.
The ATEX non-return valve is an ATEX certified safety system for the isolation of an explosion and is suitable for use in Ex zone 22 (ext.) and up to Ex zone 20 (int.).
Where should the Valve be installed?
The valve should only be fitted in to horizontal ducting to enable the flap to drop when needed as this is done by its own weight. See below min & max distance guidance for valve installation:
- For the Diameter: 200mm / 2-7 metres from filter
- Then Diameter: 250-400mm / 3-7 metres from filter
- Diameter: 450-1000mm / 4-7 metres from filter
Ensure that the duct run from the filter unit to the valve is also ATEX rated. Ensure that the ducting can stand the explosion pressures.
The temperature range of the valves are -20°C to 40°C.
Suitable for organic and non-metallic dusts up to 200 BAR M.S.I.
How much does one cost?
The ATEX non-return valves that we offer come in diameters ranging from 200 – 1000mm and the prices start from £1138.
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