【 Weak current College 】 gas extinguishing system protection automatic pressure relief design and installation (2)

5 structure and working principle
5.1 structure characteristics
Pressure relief estuary mainly consists of decorative panels, body parts, valve components, devices and close execution-driven parts or equipment for fixed frame components, parts and accessories of assistive devices. Relief of minutes without power-series structure and power series structure. No power supply-series in the product device set pressure adjustment drive ├stainless part or parts. There is a power series in the product device set pressure detecting device and electric drive units.
5.2 works
Pressure port installed in exterior or interior protection area relief holes in the usual is normally closed state. When a fire protection district, gas fire extinguishing system before the release of fire extinguishing gas, in order to ensure chemical concentration, dipping time guarantee success, fire-extinguishing system in the protection zone of ventilation, air conditioning will automatically power off, the ventilation pipe and door and window is closed. Gas extinguishing system start releasing fire gases, causing a rapid pressure over the region protection building design allows pressure. At this point, if the protective area installed without power series structure of pressure relief, when acting on the blade or cover components of gas pressure value reached setting pressure value, overcoming pressure adjustment drive ├stainless part or driving parts immediately driven advance force leaves or cover opening pressure relief; if protection area installed power series structure, when the pressure relief device for detecting set pressure value is reached, a telecommunications, to electric drive units, electric drive units quickly open blade or cover, discharge pressure gas discharge protection area, to avoid building walls, doors, Windows, glass envelope damage and cause fire. When the protective zone of the pressure drops below the set value, no power series and have a power series pressure lips leaves or cover will automatically shut off, the maintenance of fire protection district fire extinguishing agent, so that its concentration reaches a certain number of extinguishing the fire of impregnated time will exterminate.
6 How to properly select the relief port
Design and installation of pressure relief port is to ensure that the gas fire extinguishing system protection area building envelope of secure, reliable, and fast, timely fire fighting success. So relief of product quality is vital, how to properly select? mainly based on the pressure of the main performance parameters, as follows:
6.1 relief port inspection report should be
The user selects the relief port products should be fixed fire extinguishing systems and fire-resistant components for quality supervision and inspection center, and get a test report. In order to guarantee the product's basic features and functions, especially no power supply is particularly important for the pressure outlet.
Pressure relief vents there is currently no national, industry, local standards, the enterprise's corporate standard main performance parameters are inconsistent, the difference between the higher product quality. Some manufacturers get is not a fire department recognized in other sectors of the national inspection report. The other sectors of the inspection report, the only 2-3 performance parameters, completely based on enterprise custom content detection, there is no guarantee that the role of the relief port.
Fire Department recognized national inspection report, the enterprise standards experts must first be adopted by article audit, function, performance parameters are not reasonable, will not be detected, thus ensuring the release of the product's basic function. Qualified non-power-pressure relief and development are at the actual ratio of the power of pressure relief, difficulty to do testing. At present most of the non-power-relief port through the national testing is relatively small. It is recommended that the user selected, each type of relief port should have a structure that corresponds to the inspection report, which basically can guarantee the quality of the pressure of the product.
Choosing the correct startup 6.2
Pressure relief vents starts with no power-and power-two types. No power-type pressure relief, without power, setting pressure value will be automatically turned on or off, simple structure, fewer parts, reliable, low failure rate, and ease of installation, the usual basic without maintenance, prices etc. Due to the construction site cannot detect pressure relief vents open action pressure value, only the measuring device is open and flexible. The unit is factory-qualified manufacturers have debugging, suitable for the more rain and snow, the outdoor temperature is large and often loses power and no management poor environment installed.
There is a power-off, the pressure immediately after power up to fire power to work correctly, when you reach the set pressure value is automatically turned on or off. Structure is complex, parts, mainly composed of electrical components and mechanical parts. This type of device for pressure test device accuracy is high, and electrical components are not able to shock and vibration, and moisture-proof. Therefore the failure rate is better than no-decompression of high power, usually subject to periodic testing, and product price is higher. On-site installation can be onsite testing pressure relief vents open action pressure value, the device opens a feedback signal. Suitable for less rain and snow, temperature-25 ° C to + 55 ° C and constantly and have the ordinary management of better environment for installation. If installed in a less favourable environment, you should do a rain and snow in the special handling.
6.3 reasonable choice model specifications
The pressure of the product specifications model is provided by the enterprises themselves, confusing. The key is to design and selection of users should be aware of the pressure relief of product performance and what are the main parameters and structure analysis of the various manufacturers of pressure relief function with any of the product, performance parameters are reasonable in order to make the right choice to ensure product quality.
The correct setting and closing pressure 6.4 values
Opening pressure value set is the pressure of the product as one of the main performance parameters. Opening and closing pressure values in the opening pressure value is even more important, it is the pressure of the valve opening pressure index value. The value of value determines the protection zone, the security of the building envelope is not subjected to gas pressure damage and whether the fires in a timely manner. Having access to relevant information and its analysis, the pressure of the mouth opening pressure value is 1.1 + 0.1KPa, more reasonable. Pressure value exceeds the value will be high 1.2KPa, will affect the protective zone, doors, Windows, glass wall building security, pressure values lower than 0.8KPa following, will result in fire extinguishing agents unnecessary loss, which will inevitably affect the fire effect or even offFire.
6.5 concern hoist latency
Hoist latency, expressed on latency and close the latency, the parameter is set to ≤ 2 seconds. Open the latency indicates that protection zone, gas up the value of the maximum working pressure, the pressure of the valve should be less than or equal to 2 seconds fully opened or achieve the corresponding open, so that the protective area of timely relief pressure gas to avoid rising gas pressure, leading to building walls, doors, Windows, glass envelope damage and cause fire. Close the latency indicates that protection zone for gas release, overpressure protection area to minimize the pressure value is set to close the pressure values the pressure of the valve should be less than or equal to 2 seconds to shut down or to the appropriate off, avoid protection zone extinguishing agents unnecessary wastage, the maintenance of protection zones, the concentration of fire extinguishing agent is conducive to the timely fight fire. Maximum working pressure value and open close working pressure values for left and right margin in General, manufacturers may also 1.5KPa according to user requirements set on its own. Qualified relief mouth open and latency is less than or equal to 2 seconds, mainly by reducing the pressure of the valve and drive actuator design is reasonable decisions.
Most people think there is a power-type pressure relief mouth than no power-type pressure relief port opening pressure value accuracy is high, the pressure relief valve opens another mouth movements faster. After testing, qualified without power-type pressure relief port and a power-type pressure relief mouth comparison: no power pressure relief and protection area pressure values correspond to open, power-type pressure relief port when the protective area pressure value higher than the pressure at the set value is 0.05 ~ 0.10KPa, cited the gas flow into the opening pressure detector narrow channel, has a certain distance and partial loss of pressure, pressure value will be lower; no power supply-power than a relief valve opens at-speed about fast 0.3S about, has the power to the electromagnet type pressure relief mouth than the power of micro-motor-type pressure relief vents and about quickly 0.3S.
6.6 reasonable choice of size relief
At present the domestic manufacturer specifications for pressure relief are not harmonized at the various manufacturers of pressure-relieving area and dimensions and the pressure hole sizes are not consistent with the general release in the area between the 0.04 ~ 0.20m2. Each protection area pressure hole area or number of mouth install pressure relief and the total pressure relief area, must not be less than the calculated pressure relief area Design Institute. Relief of pressure relief area shall be equipped with protective area, if it exceeds too large will cause fire extinguishing gas unnecessary loss of influence fire effect. IG-541 mixed gas and carbon dioxide extinguishing systems of protection zones, it is recommended that you should configure two or two above the pressure, especially power type pressure relief port must not only use one, or more than a single pressure relief vents 0.20m2 into relief area small two or two above the pressure relief, uniformly distributed in the protection zone, in order to ensure the protection of the region surrounding protection structure building safety and not damage.
The user should select the manufacturers stable version and the basis for the relief of area is the production release of the product, do not select the design and processing according to user temporary non-standard type pressure relief, and the product quality is difficult to be guaranteed. If the number, you do need a separate design and manufacturing of non-standard type pressure relief, the user should test the manufacturers site, detect pressure and closing values are accurate. In particular, no power supply type automatic pressure relief needs user conduct field tests and testing.
Following a comparative test in order to understand the protective zone set size of different area pressure difference and the pressure of the actual role of get up. Two structure the same without power-pressure relief, the pressure difference 50 per cent of the area, in the same 100m3 above lab, the same test bottle filling pressure within the group, under the same conditions, test procedures and parameters are as follows.
Small relief area relief oral test process: gas release time 4S, protective area pressure value reached 1.1KPa, opened at the same time, the pressure of the pressure immediately rose to the post, and then immediately 1.2KPa reduced to 1.0KPa, after pressure relief vents closed 1.4S, protective area pressure quickly drop to 1 ~ 2S 0.4KPa, rose to 0.7KPa after, voltage for a few seconds and after approximately 6S to 0 values.
High pressure area relief oral test process: gas release time 4S, protective area pressure value reached 1.1KPa, opened at the same time, the pressure of the pressure value is no longer rising, drop to 0.9KPa, after pressure relief vents closed 1.2S, protective area pressure value quickly to 0 value rose to 0.4KPa, about 5S is reduced to a value of 0.
Through the pressure relief area size different comparison test pressure relief vents, evident: (1) relief of area is small mouth opening of pressure, the pressure will rise, gas loss less conducive to rapid fire; relief of area is a big relief port opening, the pressure loss no longer rising, gas is too large, is not conducive to the fire quickly extinguished. (2) the relief port ensures protection of security in the region surrounding buildings. This test model is based on a pipeline heptafluoropropane fire-extinguishing system design, only my company uses. According to collect domestic manufacturers of enterprise standards and inspection reports, generally a few cubic meters to more than ten cubic capacity large test laboratory experiments. I am of the view that the relief port should be more than a laboratory model 100m3 tested before the real response to the pressure of the various functions and parameters, and more relevance and reliability.
6.7 leakage also select indicator
Leakage rate also known as air leakage, referring to the pressure of the pipeline or a volume equal to the temperature and pressure conditions, the relief port installations in practical work conditions and ideal seal State air leakage volume in unit area. Pressure relief vents from the appearance you can see the structure of the valve sealing performance is good or bad. Action from the pressure relief vents open test, the pressure outlet valve tightness poor, protective zone of the pressure value is difficult to achieve the set maximum opening pressure value will cause fire extinguishing gas spews from start to fire extinguishing gas impregnating the end of the period of continuous erosion, reduce the fire extinguishing concentration, affect the normal extinguishing effect. Heptafluoropropane extinguishing system impregnation should generally 1 ~ 20min, communications room, computer room of electrical equipment fire, should adopt 5min dipping time. IG541 mixed gas fire extinguishing system for immersion time is 10-20Min, the communications room, computer room use 20min.
Select the appropriate installation 6.8
Pressure relief vents with indoor and outdoor installation of two types. Pressure relief vents from the protection zones are installed in pressure relief cavity called indoor installation. Indoor installations come in two forms: one is embedded, the pressure relief vents installed for side wall protection area of the pressure hole, this installation method is applied up to a ceiling of embedded, the pressure mounted on top of the protective zone of the pressure hole, this installation mode is very small. Indoor installation for new construction and renovation of the old projects, particularly suitable for high-rise buildings, installation, debugging, are safe and convenient, while embedded installation requires the pressure hole dimensions accurately.
Pressure relief vents from the protection zone for the installation to the relief port known as outdoor installation. Outdoor installation has two forms: one is a wall-mounted, the relief port installed in the pressure hole in the wall, this installation method more; the other is embedded, install fewer. Outdoor installations adapted to new projects, tall buildings with the building outer wall decoration has just finished, scaffolding not disassemble scaffolding installation before use. Wall-mounted installation simple and fast.
6.9 correctly select the pressure outlet is equipped with auxiliary equipment
The pressure outlet is equipped with auxiliary equipment and the pressure outlet is equipped with a fixed grid (draught) or decorative Panel, it is installed on the other end pressure relief port hole or wall. Outdoor-type pressure relief port installed in the protection zone wall or aisle wall relief cavity, and the accompanying fixed grid (draught) or decoration Panel is installed in the protection zone, wall, room-type pressure relief port install from the protection zone, supporting a fixed grid (draught) or decorative panel wall from the protection zone or aisle wall relief holes, auxiliary equipment installed on the primary role is rain, snow, beautiful and anti-theft. Fixed grid (draught) parts of general use of aluminum alloy material processing, embedded or installed in the pressure hole, rain and snow, beautiful and anti-theft function. Decorative Panel part structure looks basically the automatic pressure relief panel appearance consistent, hanging in the pressure hole. Banking Treasury or Museum installed pressure relief, recommended indoor type pressure relief, will release in the mouth and decoration Panel try an micromove switch, when the pressure of a few mm distance from the wall will alarm, the pressure hole at the other end of the installation of Security window and diffusers.

7 installation considerations
7.1 installation location determine
Construction units and personnel should know the design department or user to choose the type of the relief port (with power-or-no power supply), installation (outdoor or indoor), model, and protective zone installation number, based on design drawings and the pressure of the product usage manual, comprehensive analysis determines the pressure at the installation location. Pressure port installation location there are three types: the first sets the walls in the protection zone; the second is the protection area without walls, installed in the aisle on the wall; and finally a protection area neither external nor internal wall of the corridor. Select the location of the pressure relief vents should not affect the pressure of work, contribute to the rapid fire extinguishing gas overpressure free emissions to the air outside the building, the emission of the path should be the shortest.
7.1.1 Installing wall (figure a)

Most of the protective zone of existing building building exterior and interior corridors, according to the 2005 GB50370-gas fire-extinguishing system design standard "GB section 3.2.8 stipulates that relief should be set in the wall outlet. This means that priority should be installed in the walls, there is a problem if installed OK, you can select an aisle interior walls.
7.1.2 corridor wall installation (figure a)

At present most of the design department in gas extinguishing system network floor plan, are available in the protection zone to determine the location of the pressure relief vents, most in the installation of gas fire extinguishing system pipeline before considering selection and installation. Larger buildings, many of the protection area of the wall is not near the building of the wall, aisle interior walls. Pursuant to the provisions of GB50370-2005 national standard in article 3.28, "protective zone exists on the external walls, they should be located in the exterior wall; protection zone does not exist, you can consider external walls in the interior walls and corridors separated, such as b on the" install.
7.1.3 no walls nor the corridor walls installed (figure a)

Oversized architectural buildings, some of the protection zone are neither external nor corridor walls for this kind of protection zones, as in Figure 3 b district, GB50370-2005 national standard addressed recommendations in no venting of priority into no-man's protection zone, or near the outer wall of protection zone installation, or install specialized fire smoke exhaust pipelines to quickly discharge the gas fire extinguishing agents to the outside the building. Gas fire extinguishing system in actual fighting, pressure exhaust gas, often for hot gas or contains a lot of smoke or flames, heptafluoropropane fire extinguishing agent has a pungent; carbon dioxide gas reached 8%, breathing difficulties, loss of consciousness or even suffocation, life-threatening. So the pressure from the fire gases should be timely open ventilation equipment and toward building outside the doors, Windows, so that as soon as the gas release and ventilation.
In short, the protection zone sets the position of the pressure relief vents, designers and builders respond to various factors in thoughtful, must not arbitrarily determined.
7.2 installation height
Pursuant to article GB50370-2005 GB 3.2.7 stipulates that "heptafluoropropane fire extinguishing system for the pressure outlet should be protection zone clear height of 2/3 or more". In other words except heptafluoropropane gas fire extinguishing system for the pressure outlet, along bottom edge of the protective area of not less than the height of 2/3, other gas fire extinguishing system for the pressure outlet installation height there is no limit. Currently most used IG541 heptafluoropropane, mixed gas, carbon dioxide and most other proportion of gas fire extinguishing agents are heavier than air. Gas extinguishing systems are installed in the nozzle protection area in the top, with an angle down spraying. Gas fire extinguishing system in the spray process, prevention of fire extinguishing gas within the ground, the largest proportion, fire extinguishing concentration is also the biggest, is conducive to quickly fire fighting, with the height of the ground rises fighting gas density reduction, protection of the top most aggregation is compressed air protection area. If the pressure relief port setting in the protection zone clear height of 2/3 position, release the excess pressure at release will be compressed gases most, so reducingA fire extinguishing gas loss, both to ensure the protection area of the building envelope is not damaged, ensure a fast fire fight.
Various types of gas fire extinguishing system protection zones along the bottom under the pressure of the installation height should be assumed in the protection zone 2/3 or more.
7.3 installation considerations and steps
7.3.1 considerations
7.3.1.1 before installation please read the release of the product, "manual", in strict accordance with the instructions require the installation, testing and maintenance.
7.3.1.2 installation request handle with care to avoid automatic pressure relief deformations caused by the destruction of the structure and performance, the result does not work, particularly with power-type pressure relief.
7.3.1.3 appliance is not inverted, or otherwise does not work.
7.3.1.4 all producers in the pressure of the factory has passed the debugging should open device to regulate the internal parts.

8 inspection and maintenance
8.1 to ensure pressure relief vents can work properly after installation, you must establish the appropriate maintenance of the system, and the specialist is responsible for the regular inspection and maintenance, the equipment in good working condition.
8.2 maintained personnel must be familiar with the appliance of performance parameters, actions, proceedings, and the pressure of the structure and working principle.
8.3 normal use, there is a power-relief vents should be one quarter turn operation test at least once; no anomalies may continue to use. Each inspection should complete records for future reference. Reference documents:
«1 2600 GB50370-2005 the gas fire-extinguishing system design specifications ".
«2 Eclipse GB50193-93 the CO2 fire-extinguishing system design specifications ".
«3 2819 GBJ110-87 the Halon 1211 fire-extinguishing system design specifications ".
«4 2819 DBJ15-23-1999 heptafluoropropane (HFC-227ea) clean gas fire-extinguishing system design specifications ".
«5 DG/2600 TJ08-306-2001 the inert gas IG-541 technical specification for fire extinguishing system.