Check valves

All about check valves

Ventilation systems require reliable protection against reverse air flow. This is precisely what check valves are used for. These mechanisms ensure stable air exchange and energy savings. Without them, it would be impossible to imagine domestic systems, professional equipment for livestock/poultry farming, or industrial facilities.

What is a check valve and what are its functions?

A non-return valve in ventilation systems is a mechanism that automatically blocks air from flowing back into the room. Its main function is to prevent reverse flow. If the system is working properly, the air flows out. The valve remains closed when not in use, preventing the ingress of moisture, dust or unpleasant odours.

It is important to distinguish between a ventilation check valve and a conventional damper. A damper only mechanically blocks the duct and requires manual control. A valve, on the other hand, operates automatically in response to pressure changes. An air flow restrictor is effective in round-the-clock operation.

There is also confusion with supply valves. This device creates controlled access to fresh air from outside. A ventilation check valve, on the other hand, prevents stale or cold air from returning. Both elements are complementary parts of the ventilation system but perform different roles.

Types of ventilation check valves

There are several design options for check valves. The most common among them are as follows:

• Petals – have light flaps that open under air pressure. Suitable for domestic systems.
• Membrane – made of elastic material, ensure a tight fit and cut off even the slightest flow. Used where tightness is important.
• Gravity – the flaps open under pressure and close under their own weight. This is the simplest and most affordable valve option
• Spring – in this case, the flaps return to their original position thanks to a spring. Ensures fast response and high reliability.

Regarding the noise generated by the check valve during operation: petal and gravity models are usually quieter. Spring and diaphragm valves can create additional acoustic effects in large ducts.

Ventilation systems also often combine different types of check valves in a single network for optimal performance. For example, diaphragm valves are installed in areas with a high risk of contamination, and gravity valves are installed at the outlets to the premises to provide basic protection against air backflow.

Check valves in the ventilation of poultry farms and livestock complexes

A stable microclimate in large farms is the key to animal health and productivity. Poultry farm ventilation must ensure an optimal balance of:

• humidity;
• temperature;
• air freshness.

This is where check valves become indispensable. They protect the premises from sudden pressure drops and the ingress of cold air when the fans are turned off.

The situation is similar in cowsheds. Ventilation of a cowshed without valves risks losing its effectiveness, as unpleasant odours or even harmful gases can penetrate through the air ducts. With the right equipment, cows get sick less often and milk production increases.

Ventilation in piggeries has even stricter requirements. In such premises, it is important to control the level of ammonia and carbon dioxide. Here, the check valve acts as a barrier that prevents contaminated air from returning.

It should be noted that valves are part of a comprehensive approach. They are included in systems offered by manufacturers of poultry and livestock equipment and are always installed together with fans, shafts and microclimate sensors.

It is important to understand that check valves are part of a comprehensive approach to the organisation of ventilation systems in livestock and poultry farms. Such shut-off mechanisms work in conjunction with fans, shafts and sensors to form a single microclimate support system.

How to choose a check valve for ventilation?

The first criterion when choosing check valves is size. The air backflow preventer must match the diameter of the ventilation duct to avoid leaks.

The second criterion when choosing check valves is the material. Plastic is suitable for domestic systems, while stainless steel or aluminium, which can withstand aggressive environments, is suitable for industrial systems.

The type of fastening is also important. Surface-mounted models are easier to install, while built-in models look more aesthetically pleasing and are more airtight.

It is worth distinguishing between solutions for homes and agricultural facilities. Farms with large numbers of animals or birds require more durable check valves, as they operate in more difficult conditions: high humidity, ammonia, dust. Domestic models cannot cope with this.

Specialists at VADA, where you can purchase backflow prevention devices, advise focusing on the integrity of the system. If you are selecting a check valve for ventilation in a pigsty or cowshed, consider the characteristics of the entire network: the number of fans, the presence of automatic control, and the total area of the premises.

Where to buy backflow valves for ventilation in Ukraine?

The VADA online store is a reliable choice when purchasing shut-off mechanisms. The market specialises in professional ventilation systems. The catalogue features not only various types of check valves, but also:

• supply devices;
• shaft and industrial fans;
• installation accessories.

A wide range of necessary devices and equipment can meet all production needs. You get a comprehensive solution, not individual elements. Another advantage of buying from VADA is that all products are quality-tested and meet the requirements of agricultural and industrial facilities, as well as European standards in general. The company provides non-stop service and expert support.

Not sure which check valve to choose for your farm or apartment? VADA store consultants will help you choose the best option, taking into account the characteristics of the premises, the heating system and the intensity of air exchange.

VADA is not just a place where you can buy equipment for poultry or livestock farming. It is a partner that helps you create a stable and healthy microclimate, reduce energy costs and ensure the longevity of the entire ventilation system.