Acses nv - Operational Manual of the VSH system

Venting Of Smoke And Heat From Fire : The "G1 System"
Operational Manual

	1.0 GENERAL INFORMATION - STANDARDS OF REFERENCE 1.1 The phases of a fire 1.2 Purpose of the venting plant 1.3 Basic principles 1.4 Standards of reference

	2.0 THE UNI 9494 STANDARD

	3.0 THE "G1" SYSTEM 3.1 Description of the "G1" system 3.2. The "G1" system components 3.2.1 The actuator cylinder 3.2.2 Thermal valve 3.2.3 Pyrotechnic actuator 3.2.4 CO2 cylinders 3.2.5 Revolving union 3.2.6 Bracket and connection to frame 3.2.7 Selector valve 3.2.8 Manual valve box 3.2.9 Manual ventilation valve 3.2.10 Detection and control trigger box and detectors

	4.0 SYSTEM CONFIGURATIONS AND OPERATION 4.1 Selection of the plant configuration 4.2 Technical data 4.2.1 Cylinders 4.2.2 CO2 cylinders 4.2.3 Thrust 4.2.4 CO2 cylinder selection 4.2.5 Theoretical and practical thrusts for 40-mm bore cylinder. 4.2.6 Components diagram 4.2.7 Overall cylinder and bracket dimensions diagram

	5.0 INSTALLATION - INSPECTION - TEST - MAINTENANCE 5.1 Installation 5.1.1 The cylinder 5.1.2 Automatic valves 5.1.3 Detection and control plant 5.1.4 Manual valve box 5.1.5 Manual ventilation valve 5.2 Inspection 5.3 Test 5.3.1 The actual test 5.4 Maintenance 5.4.1 The cylinder 5.4.2 Valves 5.4.3 CO2 cylinder


	1.0 GENERAL INFORMATION - STANDARDS OF REFERENCE

	1.1 The phases of a fire A fire usually develops in four phases: the "beginning" or "incubation", the "extension", the "generalisation" (that follows the "flash over") and when it is put out. It is absolutely necessary that the venting plant intervenes as soon as possible, and that is during its beginning or during the first extension phases. If the plant fails or intervenes too late, it is unlikely that its purpose of protecting the people inside and the structures will be fulfilled.

	The beginning phase, the duration of which varies according to many factors, is not characterised by a heavy production of smoke or heat. Therefore, intervention is timely only if personnel are in the right place at the right time or, better yet, if there is a good detection plant installed. A lot of smoke and heat are produced during the extension phase. Temperature and the speed of combustion rise very quickly. At one certain point, the ambient temperature is such that the "flash over" point, or an "explosive generalisation", is reached. The building is seriously compromised at that point. It is important to observe how an efficient smoke and heat venting plant remarkably delays the fire from reaching the "flash over" point so as to allow more time for the firemen to arrive. During the phase when the fire is put out, the fire ends due to depletion of combustible material. The smoke at the ceiling (not above the flame) reaches temperatures of 300-400°C, and above the flame temperatures reach 800-1200°C, depending on the combustible material. Above the flame, and at ceiling height, it is easy to find 800°C. This gives you an idea of the thermal test roofing is subjected to. 1.2 Purpose of the venting plant In the event of a fire, the smoke and heat venting plant must create a "draught" as close as possible to the top of the fire. This draught has the aim of taking a large amount of high-temperature smoke out so as to avoid it from dropping down to a man's height when it accumulates. Furthermore, the same venting system and surrounding area is thermally stimulated by venting a large mass of hot smoke and therefore pulling in air from the outside to ambient temperature, but the thermal stimulation over the entire floor structure greatly diminishes. Another important effect is the dragging of all the burned "lapilli", which become detached in front of the flame, in the rising current. If there is no draught, these lapilli are thrown around and contribute to accelerating the fire's expansion. In order to increase the plant's effectiveness, it is necessary that the smoke can not freely expand horizontally once it reaches the ceiling, but is instead held back in "caissons" made up of structural layers or additions. The maximum recommended size of these compartments is 1600 sq. m. Contrary to what the old theory dictated, it is absolutely important to create a good airflow from underneath. The French standards foresee a ratio of at least 1:1 with the open roofing surface, and the more demanding German standards call for an inflow surface double that of the outflow. 1.3 Basic principles In general, the basic principles on which a plant is built are: abide by the useable opening surface sizing that was calculated with the aid of UNI 9494, break up the venting surface as much as possible, equip the system with at least two controls, study the division of the fire "zones" well, and verify there is a good supply of fresh air coming in from below (also door openings and window openings at man's height are acceptable as long as they can actually be used at the right moment). Whenever possible, install a smoke detection trigger box. 1.4 Standards of reference For Italy: UNI 9494, April 1989. Foreign references: Assémblée pléniére des Assurances contre l'incendie - Regles relatives a les exutoires de fumée et de chaleur - 1980; Ministère de l'interieur - instruction technique no. 246-247, J.O. 4.5.82; * DIN 18232, parts 1, 2 and 3; * NFPA, code 204M, A Guide for Smoke and Heat Venting - 1985. Prior to publication of UNI 9494, the most specific and detailed publication in Italy, there was the "Italian Fire and Industrial Risk Agreement" put out by the association of insurance companies founded in 1883. This remarkably competent body was among the first to understand the importance of this means of protection and to define operating parameters not unlike those used today.


	2.0 THE UNI 9494 STANDARD

	This important document can be obtained by writing directly to UNI at Piazza Diaz, 2 - 20135 Milan, Italy. The standard regulates only one-floor buildings or the top floors of multi-floor buildings. The basic principles and tables for sizing the plants are found within. We will briefly list below the criteria that are given for calculation and we will give you an example that clarifies the standard's interpretation, which we strongly recommend you get. A set of data is required to calculate sizing : Building area Existence of dividers that mark the boundaries of "ceiling compartments" - the area of these compartments Height of the building Type of roofing: flat, pitch, shed, etc. Height free of smoke you want to attain Is this free height lower at the divider edge or not? That is, is smoke overflowing from one compartment to another foreseen or not? Is there a fire detection plant? Is there an internal emergency fire-fighting squad? How much time is estimated for arrival of the firemen? What is the fire's speed of development? (high - average - low) Let's take a look at the calculation for sizing a typical building. Building size: 80 x 160 m; 12,800 sq. m. area, equipped with load-bearing beams that create ceiling compartments. These beams extend vertically from the ceiling for 3 meters, and the compartments each have an individual surface area of less than 1600 sq. m. Building height: 10 m Flat roofing Height you want to keep free of smoke: 7 m The smoke must not overflow the dividers. In the event smoke overflow is foreseen, or in the event the individual compartments have an area greater than 1600 sq. m., you have to calculate the correct YC height by using formula "1". Mingardi Magnetic is at your disposal to examine the specific case together with you. There is a smoke detection plant There is no internal fire-fighting squad Arrival time of the firemen is estimated at 15 minutes Development speed: average. Since there is a detection plant (par. 6.3 of the standard), the alarm time is equal to zero. In the contrary case, it is considered 5'. The intervention time in this case is 15'. (It would conventionally be 5' if there was an internal squad.) By adding the alarm time to the intervention time, you obtain the "conventional length of time foreseen for the fire's development". This helps us to get into table 11. The development speed, unless it involves unusual materials, can always be assumed as "average". This table furnishes us with the "sizing group" that is represented by a number between 1 and 7. We will enter the corresponding column of table III with the predetermined number. The other data we need to get into this table is the height free of smoke. This is the final table from which we will extract the "alpha" coefficient. The alpha coefficient is the percentage of the building's surface that must be open for venting. It is necessary to pay maximum attention to this fact. The surface you obtain is the useable surface, i.e. the actual surface. Just for your information, a dome type of venting system, put on the roofing, has an aerodynamic coefficient that rarely reaches values greater than 0.65. Transom or protruding windows turn out to be infinitely worse with regard to efficiency, but it does not appear that tests have been carried out to determine the coefficient. It would be necessary to evaluate the influence of wind on shed frames, which varies according to the shed's position and row. We have had information that tests on scale models of the roof to be evaluated have been carried out in Germany. Some people calculate the useable surface (U.A.S.) of the vertical windows as the sum of the rectangular and triangular areas uncovered by an open window's door. This is absolutely untrue. It is necessary to multiply this data by at least 0.25 to give it some safety margin. Furthermore, the window frames should be externally transom and are not to be opened more than 45° - 60°. A wider opening or, even worse, an overturn exposes the window to ingestion of air that pushes the smoke back inside (further diluting it and therefore increasing its mass) instead of venting it - the complete opposite of what is necessary. As regards the control systems, the standard requires that there be at least two. The main one should be automatic when reaching a temperature that usually stabilises at 68°C. In special cases, you can calibrate the system 20°C above the maximum ambient temperature that is normally reached. The same precaution should be taken if sprinkler plants are installed. The second control can be either automatic or manual and, unlike the first control that must be absolutely individual, it can operate groups of venting systems as long as they are inside the same fire zone. The G1 system was conceived to be able to easily build plants meeting the UNI 9494 standard.


	3.0 THE "G1" SYSTEM

	3.1 Description of the "G1" system This is a pneumatic system that flanks the well-known "S1" low-voltage electrical operation system. The "G1" system is made up of pneumatic actuators having various strokes, bores and versions that are installed with the proper brackets. The energy is supplied from small CO2 cylinders that are opened by automatic valves. There is also a complete range of accessories available: a smoke detection trigger box, smoke and temperature detectors, an emergency box, selector valves and manual valves for ventilation, and components that will be described in the next paragraph. 3.2. The "G1" system components 3.2.1 The actuator cylinder It is constructed in various set-ups and bores, simple or double effect, with end-of-stroke lockings at both ends or at only one end or with both ends free. Two bores are available, 40 and 50 mm, which permit strong thrusts and low pressures. For example, the 40-mm diameter piston has a thrust - pressures being equal - of more than 30% than that of the 35-mm piston and 56% more than the 32-mm piston. Required thrusts being equal, you can reduce the pressure by 24% compared to the 35-mm and by 36% with respect to the 32-mm, all to the advantage of safety and operation graduality. The obtainable thrusts and the calculation procedures are shown in paragraph 4.1. Strokes of 180, 350, 550, 750 and 1000 mm are available off the shelf, whereas special strokes can be prepared upon request. The strokes shown were selected in correspondence with the electrical actuators' standard for the sake of uniformity. It is easy to use the cylinders with the locking feature also for ventilating the room through connection to the compressed air line 3.2.2 Thermal valve This is a perforation group in which a ballasted needle charged by a mechanical spring is kept in an armed position by the thermofusible vial. The valve is strictly shipped unarmed for safety reasons. In fact, an accidental jolt would cause the needle to exit about 10 mm with the possibility of injuring the operator's hands. The thermal valves are built in two main versions. One is for direct connection to the cylinder by a revolving union with a 14 x 1 male thread, and the other has a female 1/8" gas outlet for nipples purchased from the market to connect to the plant by pipes (normally in copper). 3.2.3 Pyrotechnic actuator This is a pyrotechnic device similar to the one found in airbags and in automobile seatbelt pretensioners. Activated by the passage of electrical current, it breaks the vial, priming the cylinder's opening process. The pyrotechnic actuator can be involuntarily activated by the circulation of strong currents (e.g. high-voltage lines) or by bolts of lightning striking nearby. The power supply lines are to therefore be kept well away from the motive force lines. Contact our technical-commercial department for further information about this subject, about electrical wiring and the operational current specifications. The pyrotechnic actuator has a ten-year useable lifetime. It is a normal rule of thumb in Italy to replace pyrotechnic devices every four years. 3.2.4 CO2 cylinders These cylinders constitute a completely independent source of energy, and it is for this reason that it is necessary they be of excellent quality and of a calibrated charge. They are available in various sizes ranging from 20 up to 500 grams. It must be pointed out that liquid carbon dioxide behaves unusually at certain temperatures, and for this reason Mingardi Magnetic has cylinders in stock that are specially made for exposure to temperatures of up to 70°C and higher, i.e. those to be installed on automatic valves. Please refer to par. 4.2.4 to select the size. 3.2.5 Revolving union This is used to support the piston and permit its rotation during the frame's opening. Only one is generally required because the automatic valve is already equipped with its own union. There is also a simplified non-revolving union available. The revolving union and the fixed union terminate with a female 1/8" gas so that unions purchased from the market can be mounted for maximum versatility. 3.2.6 Bracket and connection to frame The bracket permits assembly in three positions to facilitate the installer's job. The connection to the frame is the same used with the S1, D6 and D20 actuators and therefore lets you use the same holes. 3.2.7 Selector valve This valve permits the cylinder to be pneumatically fed from two sources. One part is normally connected to the thermal valve with a direct connection (male 14 x 1), always ready in case of emergency, and the other part is connected to a manually-operated CO2 cylinder box or to the compressed air line for the everyday ventilation function. In the latter case, you also need a manual valve for opening and closing control. We wish to point out that also this valve is made in two versions, to be directly installed on the cylinder or through pipes. 3.2.8 Manual valve box It is connected to the selector valve(s). It is an alternative to the detection trigger box in taking the plant up to the UNI 9494 standard (remember that the standard requires at least two control devices, one of which is always the thermal valve). This box is always used for emergencies by breaking the glass seal and manually operating a lever that perforates a CO2 cylinder. 3.2.9 Manual ventilation valve This is connected to the selector valve. It is a 5-way, 3-position valve with spring return on the centre position, open centres, which permits opening and closing the frame. It always allows intervention, if any, of the thermal valve. 3.2.10 Detection and control trigger box and detectors It is a one-zone, simple and effective trigger box. Up to 10 smoke or temperature detectors can be connected to it. It can control both the operation of the pyrotechnic actuator installed on the thermal valve and the release of magnetos for fire barrier doors at its outlet, as well as provide power supply to sirens or acoustical fire horns. Buffer batteries must be provided (found in the catalogue). The smoke detectors are the optic type, safe and functional, or the thermal type that are to be used is smoky, dusty or very humid environments where optic detectors could give false alarms.


	4.0 SYSTEM CONFIGURATIONS AND OPERATION

	4.1 Selection of the plant configuration The G1 system if very flexible and permits adaptation of every plant to the user's needs. There are therefore various possible configurations. Our technical-commercial department is able to help you precisely define the components but in any event, the outline that follows should help you understand the installation's general guidelines. It is necessary to ask the user a list of questions. The first regards the opening he wants to obtain, possibly selected from among the standard strokes available. One cylinder, one fixing bracket and one frame connection bracket are required for each frame. In the second place, we must know if the customer has a smoke detection plant he wants to hook up to, or if he wants to install the one supplied from the catalogue expressly for our system, or if he does not plan to install a detection plant at all. Questa domanda porta a scegliere la valvola termica con l'installazione dell'attuatore pirotecnico, se viene previsto I'azionamento automatico da centralina oppure la valvola esclusivamente termica se non si prevede questo impianto. This question leads us to selecting the thermal valve with installation of the pyrotechnic actuator if automatic operation from the trigger box is planned, or the exclusively thermal valve if this plant is not foreseen. A valve and CO2 cylinder for each cylinder are necessary in all cases. The presence of the thermal valve with pyrotechnic actuator and the trigger box make the plant compliant with the UNI 9494 standard for that which pertains to the controls. If use of a detection trigger box is not expected, the plant can however be taken up to standard (remember that UNI 9494 requires that every ventilation system be equipped with a double control system). In this case, it is necessary to put a selector valve between the thermal valve and the cylinder. A pipe, generally in 6x4 copper, is connected to the selector valve and is taken up to the manual valve box that should be placed in a protected area. This box's purpose is to manually operate the ventilation systems by first breaking the glass seal and then pressing a lever that perforates a CO2 cylinder. The box normally controls one group of ventilation systems. Please refer to the following diagrams (4.2) to select the CO2 cylinder. 4.2 Technical data 4.2.1 Cylinders The cylinders are constructed to operate normally up to temperatures of 120°C and, in the event of fire, they must be able to perform only one movement at 300°C. 4.2.2 CO2 cylinders The CO2 cylinders to be installed on the thermal valve must be selected with a calibration similar to that of the selected thermofusible vial (normally 68°C). Those installed in the boxes can be calibrated for temperatures up to 45°C. 4.2.3 Thrust Theoretical obtainable force: depends on the pressure reached in the cylinder. The off the shelf cylinder has a 40-mm bore, so the thrust surface is 12.56 sq. cm. We have a theoretical thrust of 12.56 x 6 = 75.4 kg at a pressure of 6 bar (e.g. when you use industrial compressed air). With a 12-bar pressure, we have 150 kg, and with a 20-bar pressure - the maximum operating pressure - we have 250 kg. We normally base it on a 10-bar pressure to get a thrust corresponding to 120 theoretical kg. The real thrust is obtained in a highly prudential manner by multiplying the thrust times a 0.8 factor. That is to say, with 10 bar we have a minimum thrust of 100 kg. Naturally, these thrusts let us move frames that are much heavier. To calculate the necessary thrust force, please refer to the following formulas:


	PROTRUDING hinges at the top opening outwards	TRANSOM hinges at the bottom opening inwards
	Whether for protruding frames or for transom frames, which are vertical when in the closed position, the formula to use for calculating the load that must be moved by the actuator is the following:

	Where: F is the force necessary for opening the frame (expressed in kg) P is the frame's weight (expressed in kg) C is the opening stroke (expressed in mm) H is the frame's height (expressed in mm)

	DOME OR HORIZONTAL FRAME (hinged on one side)
	The weight of a dome or skylight, positioned on roofing that is horizontal or inclined up to a 30° angle on the horizontal plane, lies heavy on the hinges by 50% and on the actuator by 50%. The formula to use to determine the necessary force is the following:

	Where: F is the force necessary to open the dome or skylight (expressed in kg) P is the frame's weight (expressed in kg) Obviously, in the case a load of snow is to be anticipated, it must be added to the dome's weight prior to putting it into the formula.

4.2.4 CO2 cylinder selection
Selecting the cylinder: once you have established the required thrust, you obtain the theoretical thrust by multiplying it times 1.25. Extract the total plant volume in litres (cubic centimetres/1000 = litres). If you plan to use copper pipes, calculate 0.013 litres/meter. Also take into account the CO2 cylinder's volume.

After having obtained this data, put it into the following formula:

No. g. = Total V. x No. Bar x 2.9
Example: 550-mm stroke piston and directly connected valve
(there is no copper pipe)

CO2 cylinder = approx. 80 cm³
Pipe = 0
Cylinder 12.56 x 55 = 691 cm³

770 cm³ = 0.77 I
total

Required thrust = 80 kg
80 x 1,25 = 100 Kg.
100 x 1.25 = 125 kg of theoretical thrust

100
-------- =
12,56

7,96 @ 8 bar

No. g = 0.77 x 8 x 2.9 (coefficient) = 17.86
Select the higher size in grams, in this case being 20 grams

	4.2.5 Theoretical and practical thrusts for 40-mm bore cylinder

	4.2.6 Components diagram

	4.2.7 Overall cylinder and bracket dimensions diagram


	5.0 INSTALLATION - INSPECTION - TEST - MAINTENANCE

	5.1 Installation 5.1.1 The cylinder The G1 system was conceived to simplify installation operations to the utmost. Assemble the cylinder, fixing bracket and the connection to the frame. Mark the reference points, drill and firmly anchor the bracket and connection to the frame. Fine adjustment for perfect closing of the frame is achieved through the stay bolt the rod is provided with. Note: We advise against positioning cylinders having strokes greater than 550 mm horizontally (protruding windows) so as to not subject the rod and seals to a great deal of strain. If you need longer strokes, please get in touch with our offices. Install the cylinder by using the revolving union to be put on the outlet hole (where air exits when the rod is extracted). The thermal valve is to be installed on the inlet hole, with the selector valve - if any - placed in between. 5.1.2 Automatic valves Operations to perform to arm the valves: unscrew the cover, push the perforation pin into the valve body until, when pressing on the bulb holder, it effortlessly approaches the valve body. In this way, a check enters into its seat and blocks the perforation pin. Screw the ring nut that restrains the bulb holder, replace the cover and screw it on tight. The perforation pin screw is now armed. In the case a pyrotechnic actuator is to be installed, it will be the last piece of equipment installed on the bulb holder. Screw the CO2 cylinder on tightly. 5.1.3 Detection and control plant If this plant is foreseen, install the pyrotechnic actuator on the bulb holder. Install the detectors and trigger box by following the instructions shown on the respective instruction sheets. Connect them and install the batteries. Connect the trigger box to the mains current, wait a few seconds and then press the "reset" push button. Verify there is not any voltage at the heads of the line that would become connected to the pyrotechnic actuators. Now you can connect the pyrotechnic actuators. 5.1.4 Manual valve box The box constitutes a manual emergency operation and it is actuated by breaking the glass seal and manually lowering a lever that causes a CO2 cylinder to be perforated. The connection is normally made with a copper pipe having a 6-mm external diameter and a 4-mm internal diameter. It is necessary to machine the ends well and be sure that residue does not remain inside the pipe by blowing compressed air through. If connection cannot be made immediately, seal the ends that remain open with electric tape. 5.1.5 Manual ventilation valve Install the manual lever-operated valve, and connect it to the selector valve and to the outlet revolving union. You can use a pipe in Rilsan with an 8-mm external diameter and a 6-mm internal diameter. If you like, the connection can be made in copper pipe. 5.2 Inspection Check that the frame opens freely, that the hinges are free and that there are no obstacles or locks in the way. Check that the cylinder can carry out the entire stroke and rotation during opening is permitted. Check that all of the fittings and the CO2 cylinder are tightened. Check all of the electrical connections. 5.3 Test The best test is obviously the 100% one, i.e. with a complete test of the entire plant. This may however turn out to be too costly for the buyer who, with the approval of the fire department, could limit it expressly to the operational test. We will, in any case, take a look at how to ascertain that everything functions without necessarily having to operate the whole plant. 5.3.1 The actual test If the plant is provided with a thermal valve, heat the thermofusible vial for a few minutes until it breaks. Although the flame of a cigarette lighter or a welding torch is very hot, the fact that the surrounding environment is at a noticeably lower temperature slows down the explosion. Pay attention because when the bulb explodes, it throws small fragments of hot glass that can injure your hand if it is too close. Also pay attention to the frame's opening and the cylinder's rotation. This light inertia to heat is a safety factor against false interventions. You can disassemble the CO2 cylinder and look at the strike of the percussion pin if you want to test the thermal part without opening the frame. If the valve is complete with a pyrotechnic actuator, you must test the plant by producing smoke, even with a cigarette, right under the detector. If you do not plan on opening the frames, disconnect the pyrotechnic actuators. After the trigger box has gone into alarm status, it should detect the presence of a 24V DC voltage on the wires coming out from it. It is also possible to detect the actuators' status without damaging them by checking the circuit with a current having a maximum 50-mA intensity. We recommend you do not exceed this value, over which you risk priming the actuator's operation. We advise you to carry out this verification after having disassembled the CO2 cylinder. 5.4 Maintenance 5.4.1 The cylinder The cylinder is lubricated for its entire life. We recommend you have the cylinder make a stroke every six months, either manually or through compressed air. 5.4.2 Valves Misfire the valve with the same frequency. It is preferable to simulate an emergency once a year and make the plant go. The pyrotechnic actuator has a useable lifetime of ten years; nonetheless, we recommend it to be replaced every four years and then use those salvaged for testing purposes. The actuator, once operated, is disposable and can not be reconditioned. 5.4.3 CO2 cylinder The tare and gross weight are shown on the body. Replace the cylinder or weigh it and check to be sure it corresponds with the weight shown every six months

PLANT CONFIGURATIONS