Closers for fire doors: types, selection and requirements

Fire doors have a number of characteristics that provide fire resistance and protection against fire. One of the most important elements of these structures is the door closer. According to the legislation, such a device is a mandatory element of emergency exits and doors on staircases. Fire door closers do not need a separate certificate, it is issued in full for the entire set.

A door closer is a device that provides self-closing doors. Such a device is a rather important part of the entrances and exits in a room with a large number of people. In a fire, in a state of panic, the crowd moves forward, leaving the doors wide open. The closer in this case will help her close on her own. Thus, preventing the further spread of fire to adjacent rooms and to other floors.

In everyday use, the design simplifies the operation of the doors. Closers at drive entrances are especially convenient. Thanks to them, the passage to the entrance will always be closed, which means that neither frost, nor hot air, nor a draft will penetrate inside.

Self-closing devices are of several types.

• Top, which is installed at the top of the door leaf. This is the most common type of device. It owes its popularity to its ease of installation.
• Floor standing, installed in the floor. Not suitable for metal sheets.
• Built-in, built into the sash itself.

The essence of the door closer is pretty simple. There is a spring inside it, which is compressed when the door is opened. With its gradual straightening, the door leaf closes smoothly and silently. A distinction is made between door closers that work with a link arm and a sliding channel arm.

The link arm is inherent in the overhead door closers. Its mechanism is a box containing a spring and oil. When the door is opened, the piston presses on it, so it contracts. When the door is closed, the spring unwinds and presses against the piston. That is, the work takes place in the reverse order.

In addition to the spring, the mechanism includes:

• hydraulic channels that regulate the oil supply;
• their cross section is controlled by adjusting screws, the smaller it is, the slower the oil is supplied and the canvas closes;
• gear connected to piston and rod.

Outwardly, such a system is a converging and diverging slats. In the bottom and built-in door closers, there is a rod with a sliding channel. A special mechanism is attached to the door leaf, which, when it is opened, acts on the piston. He compresses the spring, and when it is released, the door closes.

Fire door closers must meet certain requirements.

Otherwise, their installation will be contraindicated.

• According to European standards, self-closing devices are divided into 7 levels: EN1-EN7. The first level corresponds to the lightest sheet, 750 mm wide. Level 7 can withstand a canvas weighing up to 200 kg and a width of up to 1600 mm. The norm is considered to be a device corresponding to class 3.
• The door closer must be made of anti-corrosion material and withstand temperatures in the range from -40 to + 50 ° C.
• The limit of operation. The concept includes the maximum possible number of cycles (open - close) of door operation. Normally, it ranges from 500,000 and above.
• The direction of opening the door leaf.In this regard, a distinction is made between devices for doors that open outward or inward. If the door has 2 wings, then the device is installed on both of them. For the right and left sash, there are different types of device.
• Maximum opening angle. This value can be up to 180 °.

In addition to the main indicators, the door closer is equipped with a system, allowing to regulate its work.

• Possibility to set the opening angle of the sash, beyond which the door does not open. This will keep her from hitting the wall.
• Possibility to set the speed with which the door will close up to 15 °, and its further final closing.
• The ability to adjust the compression force of the spring and, accordingly, the force of closing the door.
• The choice of how long the door remains open. This feature allows you to quickly evacuate during a fire without holding it.

Additional functions include the presence of a smoke detector, synchronization of the leafs for double-leaf doors and fixing the leaf at a selected angle. The price of closers for fire doors varies widely, starting from 1000 rubles. You can choose a suitable model from both domestic and foreign manufacturers.

Among the latter, preference is given to such brands:

• Dorma - Germany;
• Abloy - Finland;
• Cisa - Italy;
• Cobra - Italy;
• Boda - Germany.

A door closer is a small, but important element in the design of fireproof door barriers.

You can learn how to install a door closer on a door with your own hands from the video below.