In the case of very heavy rainfall, the so-called backflow may occur, as a result of which the water and sewage accumulated in the sewage system back up and flood the building. Not only utility rooms located in the basement or cellar are at risk, but also those located at ground level. To prevent this, a backflow valve should be installed, i.e. a type of backflow valve that guarantees the maintenance of only one direction of flow in the sewage system. What solutions are worth recommending to customers?
In this article you will learn:
- what are storm valves,
- how does a storm valve work,
- how to properly install a storm valve,
- what storm valves to use.
What is a storm valve?
The backwater valve is a fairly simple design, consisting of a flap suspended loosely in the body and equipped with a seal. Depending on the purpose, backwater valves can take the form of:
- single-flap or double-flap storm valves,
- storm valves for sewers with or without faeces.
These are maintenance-free elements that do not require any control or adjustment of the flap position from the outside. Nevertheless, during installation, easy access to them should be ensured, because these devices should be subject to regular inspections. It may also be necessary to occasionally replace the seal or unclog the pipeline.
Despite their simple construction, all backwater valves must meet the requirements of the EN-13564 standard (Anti-flood devices in buildings). Before installation, it is worth checking whether the device has the CE mark (compliance with European Union directives).
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How does a storm valve work?
The simple design of the storm valve means that its operating principle is simple. The flap opens freely under the pressure of sewage flowing through the pipes. It does not block its drainage in any way. It only begins to perform its proper function when, for example, due to heavy rainfall, a reverse flow occurs. Then, the backflowing sewage presses the flap of the valve against its body, closing its way into the building.
The backwater valve therefore protects the facility from flooding in a fully automatic manner. No intelligent system or manual operation is required to control the device. These types of backwater valves come in various versions, but the principle of their operation remains unchanged.
How to properly install a check valve?
Pipes with sockets and spigots are useful for installing a backwater valve. The selected installation option should depend on individual requirements, technical conditions of the building, but also on the available budget. Regardless of the location of the valve, it must be installed outside the frost zone.
The location of the valve installation and its diameter depend on how many objects the valve is to protect. External installation on one building usually requires a valve with a cross-section of 160 mm, because this is the size of the sewage system pipes. The device is then mounted in an inspection chamber on the sewer. If the backwater valve is to protect several objects, it should have a diameter of at least 200 mm and be located in a collective chamber.
A non-return valve can also be installed inside a building. In this case, it will protect either the entire facility or one selected sanitary device. The first situation requires slightly more advanced methods, because the backwater valve must be mounted at the end of the main sewage pipe - on a horizontal or vertical pipe. It usually has a diameter of 110 mm. It is easier to install a valve that protects only one device - for example, a sink. In this case, a flap with a cross-section of 50 mm is needed, connecting directly to the siphon and the end of the sewage system.
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Which storm valves should I use?
Backwater valves come in many variants, designed for installation in different places. We can distinguish primarily 6 types of backwater valves, of which the following 3 are the most important:
- Type 1 - basic type of valves used for installation in horizontal pipes. They are equipped with automatic and emergency closing mechanisms.
- Type 2 - backwater valves designed for installation in horizontal pipes, with two automatic closing mechanisms and one emergency closing mechanism.
- Type 3 - a type of valve that is installed in horizontal pipes and has an automatic closing mechanism activated by external energy. In addition, they are also equipped with an emergency closing mechanism.
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Interestingly, in addition to storm valves installed in horizontal sewage pipes, there are also variants available on the market designed for vertical installation. They are useful when a vertical pipe is the only possible place to mount this device.
In addition to traditional check valves, it is also worth taking an interest in drainage storm valves. They are mounted directly on the corrugated pipe, which drains water collected in the drainage around the building. Their additional function is to prevent rodents from entering the interior.
Storm flaps may also differ in the number of non-return flaps. Models equipped with two flaps will prove to be even more effective than their standard counterparts. Interestingly, these elements may not only respond to changes in the direction of sewage flow, but also rely on communication between the actuator and the probe placed in the flap. Then, when, for example, the pipe is filled to 80%, the flaps are automatically closed. It is worth remembering that a storm flap may also be equipped with a manual lever. The ability to manually close the flaps is useful, for example, when the building remains empty for a longer period of time.
The selection of the appropriate type of valve and its additional functions therefore depends on the specifics of each facility and the conditions in which the valve will be installed. The obligation to use such a device is specified in the Regulation of the Minister of Infrastructure of 12 April 2002 on the technical conditions that buildings and their location should meet. The following are primarily exposed to flooding due to backflow of sewage:
- rooms located below the maximum level of manholes,
- facilities equipped with drainless tanks integrated with the internal installation,
- buildings in the flood zone.
Storm valves available at onninen.pl
In the onninen.pl assortment you will find a wide selection of anti-flood devices, protecting the building against reverse flow and unpleasant odors penetrating from the sewage system. A wide selection of non-return valves in the installation wholesaler makes it easy to match the backwater valve to the technical conditions of the facility you are working on. The offer includes products from renowned brands Karmat and HL, such as:
- backwater valve for horizontal installation,
- Karmat 50 backwater valve for vertical installation, white ,
- a backwater valve with a Karmat PP DN 50 elbow or pipe sleeve,
- backwater valve with built-in rosette,
- backwater valve with electronically controlled flap HL DN160 ,
- backwater valve with manual locking and inspection HL DN125 ,
- Karmat PP DN 110 double-flap backwater valve .
Select storm valves to suit your customers' needs and ensure their safety and comfort of using the sewage system!
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