At gasified facilities, there are always systems of protection against possible leakage and fire of gas. There can be many reasons for this, and one of them is a fire in the room. A fire leads to an increase in temperature, which can reach the limit of ignition of the gas and lead to its explosion. To prevent this, special valves have been developed to cut off the gas supply in the event of a fire.
Thermal stop valve: purpose
The automatic type of valve that shuts off the gas line to all gas-powered devices during a fire is called a thermal shut-off valve. Thanks to this device, the risk of explosions, injuries and physical damage is reduced.
The installation of KTZ thermal shut-off valves is regulated by the standards set forth in the fire safety rules. They prescribe:
- Equip any types of natural gas pipelines, regardless of their complexity, branching and the number of consumer devices, with heat-sensitive control and supply cut-off systems.
- Use valves designed to operate when the ambient temperature reaches one hundred degrees Celsius as protective devices.
- Install thermal isolation modules at the entrance to the room.
Valves are marked in the form of KTZ with a number after it. The number indicates what the diameter of the gas supply pipe to which this valve can be installed should be.
Operating principle
The thermal shut-off valve consists of a body with a threaded connection, a fusible insert, a spring mechanism and an element (shutter) in the form of a plate or a ball that locks the channel.
In the initial state at normal room temperature, the valve shut-off element is cocked and held by a fuse. When ignited, the total temperature rises, reaching its mark of 85-100 degrees leads to the melting of the insert and the release of the cutting mechanism. The latter, in turn, under the action of a spring blocks the gas flow channel.
Thermal shut-off valve (KTZ) can work with any gases. After operation, it is replaced with a new one. It is possible to replace the fusible insert with another and further use of the product.
Installation Rules
In order to operate the thermal shutoff valve, it is necessary to adhere to the rules for its installation:
- The valves on the threaded connection should be installed in lines with a pressure of no higher than 0.6 MPa. Valves on the flange joint withstand pressure up to 1.6 MPa.
- The throughput of the valve should not be less than the throughput of the gas line.
- Install a thermal shut-off valve on the gas pipeline in the first place, and then the rest of the fittings.
- KTZ should be installed indoors and protect fittings not designed for high heating.
- The axis of the valve can be located in any direction.
- Note the gas flow whose direction is indicated on the device.
- Installation of the valve in places close to heating elements, the air temperature near which can exceed 53 degrees, is excluded.
- The built-in thermal shut-off valve must be checked for leaks.
- After installing KTZ, additional pipes should not exert pressure on it by bending or twisting the device.
- Access to the valve must be free and not obstructed.
Conclusion
When buying a thermal shut-off valve, you should make sure that the channel shut-off mechanism has not worked, which sometimes happens during transportation. With complex gas distribution inside the building and the presence of several fuel consumers located in different parts of the building, it is recommended that several shut-off valves are installed on each branch.