1. Process flow:

Installation of steel pipes and metal wire ducts → laying of wires in steel pipes and wiring of wire ducts → installation of automatic fire alarm equipment → debugging → inspection and acceptance before delivery for use

The main requirements for the installation of steel pipes and metal wire ducts are as follows:

2.1 The incoming pipes, steel profiles, metal wire ducts and their accessories should have material certificates or certificates of conformity, and the quality, quantity, specifications and models should be checked to ensure they meet the requirements. Inspection records should be filled out. The steel pipe requires uniform wall thickness, uniform welding seams, no splitting, sand holes or sharp edges, no concavity or flatness, and the galvanized layer inside and outside should be uniform, intact and undamaged. Metal wire ducts and their accessories should be made of galvanized and standardized products. The inside and outside of the trunking should be smooth and flat, without any sharp edges or distortion of wing edges.

2.2 Before piping, the junction box should be selected based on the model and specifications of various detectors, manual alarms, broadcast speakers, and other equipment provided by the design and manufacturer, so that the box matches the installed equipment.

2.3 When encountering one of the following situations, a junction box should be added in a location that is convenient for threading the wire protection tube:

When the pipeline length exceeds 30m and there is no bending;

When the length of the pipeline exceeds 20m and there is a bend;

When the pipeline length exceeds 15m and there are two bends;

When the pipeline length exceeds 8m and there are three bends.

2.4 The bending of the wire protection tube should not have wrinkles, dents or cracks, and the degree of flattening should not exceed 10% of the outer diameter of the tube.

The bending radius of 2.5 exposed pipes should not be less than 6 times the outer diameter of the pipe, and for concealed pipes, the bending radius should not be less than 6 times the outer diameter of the pipe. When buried underground or in concrete, the bending radius should not be less than 10 times the outer diameter of the pipe.

When the pipeline is concealed, the wire protection pipe should be laid along the nearest route and the bending should be reduced. The distance between the wire protection pipes buried in non combustible buildings and the walls of buildings and structures should not be less than 30mm. When metal wire ducts and steel pipes are exposed, fire protection measures should be taken according to the design requirements.

2.7 Wire protection pipes should not pass through the foundation of equipment, buildings, or structures. When it is necessary to pass through, protective measures should be taken, such as using protective pipes.

2.8 The allowable deviation for the installation of exposed wire protection pipes laid horizontally or vertically is 1.5 ‰, and the total length deviation should not exceed 1/2 of the inner diameter of the pipe.

2.9 The protective conduit for electrical wires laid in dusty or humid areas should have its mouth and all its connections sealed.

When laying pipelines through deformation joints (including settlement joints, expansion joints, seismic joints, etc.) in buildings, compensation measures should be taken.

2.11 The exposed steel pipes should be arranged neatly, and the spacing between fixed points should be even. The maximum distance between steel pipe clamps is shown in Table 6-l. The distance between pipe clamps and terminals, midpoint of elbows, electrical appliances or box edges should be 0.15 to 0.5m.

Maximum distance between steel pipe clamps (m) Table 6-1

Steel pipe diameter (mm)

15-20 25-32 40-50 65 or above

Thick walled steel pipe 1.5 2.0 2.5 3.5

Thin walled steel pipe 1.0, 1.5, 2.0

2.12 The pipelines laid in the ceiling should be lifted or fixed with separate fixtures or supports. With the permission of the decoration unit, steel pipes with a diameter of 20mm or less can be fixed on the suspension rod or main keel.

2.13 In the absence of a suspended ceiling, the position of the detector box is the position where the probe is installed and cannot be adjusted. Therefore, it is required to determine the position of the box according to the installation requirements of the detector.

2.14 The junction boxes used for exposed piping and the installation of fire equipment boxes should be surface mounted.

2.15 Steel pipes shall be installed and laid into boxes, and both inside and outside shall be fixed with a locking nut, and protective openings shall be installed on the inside. The length of the steel pipe entering the box shall be based on the length with full protective mouth attached to the root nut.

2.16 The support components used in boxes, wire ducts, and pipes should be fixed using pre embedded bolts, expansion bolts, expansion pipe screws, pre embedded iron parts, welding, and other methods. The use of wooden plugs is strictly prohibited. When using expansion tube screws and expansion bolts for fixation, the drilling specifications should match the expansion tube.

2.17 Various metal components, junction boxes, and box installation holes cannot be cut by electric or gas welding.

When connecting steel pipes with threads, the length of the pipe end thread should not be less than half of the length of the pipe joint. After connection, the thread should be exposed for 2-3 turns, and the surface of the thread should be smooth without defects.

2.19 Galvanized steel pipes should be connected with threaded or sleeve fastening screws, and should not be welded to avoid damaging the galvanized layer.

During the installation of 2.20 piping and trunking, consideration should be given to lines of different systems, voltages, and current categories, and they should not be threaded into the same pipe or through holes in the same trunking.

2.21 When installing piping and wiring ducts, consideration should be given to the transmission lines of alarm systems laid horizontally. If conduit wiring is used, lines from different fire compartments should not pass through the same conduit. However, if the detector alarm line adopts a bus system, it is not subject to this restriction.

2.22 The cable shaft of weak current lines should be set separately from the shaft of strong current lines. If conditions limit the use of the same shaft, it should be arranged on both sides of the shaft.

Metal pipes and metal wire ducts must be used for wiring within the ceiling of buildings.

When laying steel pipes on the same side as hot water pipes and steam pipes, they should be laid underneath the hot water pipes and steam pipes. When facing difficulties, it can be laid on top of it, and the net distance between them should not be less than the following values:

2.24.1 When the pipeline is laid under the hot water pipe, it is 0.20m, when it is above it is 0.3m, when it is laid under the steam pipe, it is 0.5m, and when it is above it is 1m.

When the above requirements cannot be met, insulation measures should be taken. The net distance between the upper and lower parts of steam pipes with insulation measures can be reduced to 0.2m.

The clear distance between 2.25 steel pipes and other pipes such as water pipes should not be less than 0.10m. When laid on the same side as the water pipe, it is advisable to lay it on top of the water pipe (excluding flammable gas and liquid pipelines). When pipelines intersect, the distance should not be less than the parallel net distance corresponding to the above situation.

2.26 The cable tray should be laid in a dry and non mechanically damaged area.

2.27 The laying of cable ducts should be carried out using separate fixtures for hoisting or fixed with supports. The diameter of the suspension rod should not be less than 6mm, and the spacing between fixed brackets should generally not be greater than 1-1.5m. Fixed support points should be set up within 0.5m at both ends of junction boxes, boxes, cabinets, corners, bends, and T-joints.

2.28 The interface of the cable tray should be straight and tight, and the tray cover should be complete, flat, and without any warping angles.

After tightening the screws or other fasteners that fix or connect the cable tray, their ends should be smoothly connected to the inner surface of the cable tray, that is, the nut should be placed on the outer side of the cable tray wall, and a flat washer and spring washer should be provided when tightening.

The outlet, corner, and turning points of the 2.30 cable tray should be located correctly, smoothly, and without burrs.

2.31 The cable tray should be laid straight and neat, with a horizontal and vertical allowable deviation of 2 ‰ of its length, and a total allowable deviation of 20mm. When installed in parallel, the tray cover should be easy to open.

The connection of metal wire ducts should not be made through floors or walls.

When metal hoses and flexible metal pipes are used as cross connections between 2.33 metal pipes or metal wire ducts and firefighting equipment, their length should not exceed 2 meters and should be fixed with clamps. The spacing between fixing points should not exceed 0.5 meters, and the ends should be fixed with locking nuts or clamps and grounded according to regulations.

When installing concealed fire hydrant piping, the junction box should not be placed at the back of the fire hydrant box, but should be connected from the side.

The grounding and protective grounding of firefighting equipment and pipelines should be constructed in accordance with the design, relevant specifications, and document requirements.

Requirements for laying insulated wires and wiring in steel pipes:

3.1 The specifications, quantities, and certificates of conformity of the insulated wires and control cables entering the site shall meet the design requirements, and the inspection records of the materials entering the site shall be filled out in a timely manner.

3.2 The transmission line of the automatic fire alarm system should use copper core insulated wire or copper core cable, and its voltage level should not be lower than AC 250V, preferably 500V, to improve insulation and anti-interference ability.

3.3 To meet the mechanical strength requirements of wires and cables, the minimum cross-sectional area of insulated wires laid in conduits should not be less than 1mm2; The minimum cross-sectional area of insulated wires laid in the trunking should not be less than 0.75mm2; The minimum cross-sectional area of multi-core cable cores should not be less than 0.5mm2.

3.4 The total area of insulated wires or cables passing through pipes should not exceed 40% of the cross-sectional area inside the pipes, and the total area of insulated wires or cables laid in enclosed wire ducts should not exceed 50% of the net cross-sectional area of the ducts.

3.5 There should be no joints or twists in the wires inside the pipes or wire ducts. The joints of the wires should be welded or crimped inside the junction box.

3.6 Lines with different systems, voltages, and current categories should not be run in the same conduit or in the same slot of the wiring harness.

When using conduit wiring for alarm system transmission lines laid horizontally, lines from different fire compartments should not be threaded into the same conduit. The use of bus system is not subject to this limitation.

3.8 The transmission line of the fire alarm should choose insulated wires of different colors. The "+" line of the detector should be red, the "-" line should be blue, and the remaining lines should be distinguished by other colors according to different purposes. However, the colors of wires with the same purpose in the same project should be consistent, and the terminal blocks should be labeled.

3.9 Sufficient margin should be left for wires or cables at junction boxes, expansion joints, fire protection equipment, etc.

3.10 Wiring inside pipes or wire ducts should be carried out after the completion of building plastering and ground engineering. Before threading, the accumulated water and debris inside the pipe or trunking should be cleaned up, and the pipe mouth should be equipped with a protective mouth.

When the cross-sectional area of the wire laid in a vertical pipeline is below 50mm2, it should be fixed at the junction box for every length exceeding 30m.

3.12 At present, China's fire protection industry is developing rapidly, and many use bus based line control. There are requirements for the length and resistance of the line laying, and during construction, the laying and wiring of the line should be strictly in accordance with the manufacturer's technical data requirements.

3.13 The joint of the wire connection should not increase the resistance value, and the stressed wire should not reduce the original mechanical strength or the original insulation strength. To meet the above requirements, the following methods should be adopted when connecting the wire:

3.13.1 When the plastic wire is less than 4mm2, exploitation pliers should generally be used to strip off the insulation layer of the wire. If there is a braided wire, an electrician's knife should be used to peel off the outer layer of the braided layer, and an insulation platform of about 12mm should be left. The length of the wire core depends on the wiring method and the required mechanical strength.

3.13.2 The wire insulation platform should be closed together, and one wire core should be wrapped around the other wire core for 5-7 turns at a distance of about 12mm from the insulation platform. The remaining ends should be folded back together and pressed onto the winding line, and then subjected to tin plating treatment.

3.13.3 LC safety wire cap: It is a copper wire cap, divided into yellow, white, and red colors, suitable for connecting 2-4 wires of 1.0 mm2, 1.5 mm2, 2.5 mm2, and 4 mm2, respectively. The operation method is to peel off the insulation layer of the wire by 10-13mm (determined by the type of cap), remove the oxide, select an appropriate wire pressing cap according to regulations, insert the wire core into the pressure connecting pipe of the wire pressing cap. If it is not filled tightly, the wire core can be folded back (double the stripping length) until it is filled. After the wire core is inserted to the bottom, the insulation layer of the wire should be flush with the mouth of the crimping pipe and wrapped in the cap shell. Then, use a special crimping pliers to compact it.

When using screws to crimp multi stranded copper core flexible wires, the core should be tightened into an eye circle shape, or a small copper nose should be used for crimping. After tin coating, it should be flattened and then tightened firmly with screws.

3.13.5 When connecting a single stranded copper wire to a pinhole type terminal post (crimping), the wire core of the connected wire should be inserted into the pinhole of the terminal post head, and the wire should be exposed to a pinhole of 1-2mm. When the pinhole is larger than twice the diameter of the wire core, it needs to be turned back and inserted for crimping. If it is a multi strand soft copper wire, it should be tightened and rinsed with tin, wiped clean before crimping.

3.3.13.6 Wrapping of wire connections: Rubber (or plastic) insulation tape is selected to start from the intact insulation layer at the beginning of the wire joint, wrap 1-2 insulation tape widths, and then wrap with half overlap. During the wrapping process, the insulation tape should be tightened as much as possible. Finally, wrap 1-2 circles around the insulation layer before rewinding. Then use black tape to wrap it, and make sure to connect it well. Wrap it with half the width of the pressure edge, and tighten the tape during the wrapping process. Seal both ends of the wire joint tightly with black tape.

After the completion of wire laying and connection, inspection should be carried out. If there are no errors, a 500V megohmmeter with a range of 0-500M Ω should be used to shake and measure the insulation resistance between wires, line to ground, line to line shielding layer, etc. The insulation resistance value should not be less than 20M Ω. Be careful not to carry firefighting equipment for shake testing. The shaking speed should be maintained at around 120r/min, and the reading should be taken after 1 minute.

4. Installation requirements for automatic fire alarm equipment:

4.1 The automatic fire alarm equipment entering the factory should be inspected for model, quantity, specification, variety, appearance, etc. according to the requirements of the design drawings, and provided to the national fire electronic products, quality supervision and testing center with valid inspection reports and other relevant installation and wiring requirements. At the same time, the equipment inspection procedures for entering the factory should be handled with the unit providing the equipment.

4.2 Installation requirements for point type fire detectors, gas fire detectors, and infrared beam fire detectors:

4.2.1 The protection area and protection radius of smoke and temperature detectors should meet the requirements, as shown in Table 6-3.

The protection area A and protection radius R of the detector

Fire detection ground area, room height, floor top slope θ

Type of device S h θ≤ 15 ° 15 ° 30 °

(m2) (m) A (m2) R (m) A (m2) R (m) A (m2) R (m) A (m2) R (m)

S ≤ 80 h ≤ 12 80 6.7 80 7.2 80 8.0

Smoke detector 630 h ≤ 8 20 3.6 30 4.9 40 6.3

3.4.2.2 The installation spacing of smoke and temperature detectors should not exceed the range specified in the limit curves D1-D11 (including D9 ′) in Figures 6-5, and the limit curve for the installation spacing of detectors should be determined by the protection area A and protection radius R.

4.2.3 The number of detectors that need to be set up in a detector area should be calculated using the following formula:

Number of detectors required to be set within a detection area of N SAK, and take an integer. The area of a detection area (m2); The protection area of a detector (m2); Correction factor, key protected buildings are set at 0.7-0.9, while others are set at 1.0

4.2.4 When installing smoke and temperature detectors on the ceiling dagger, the height of the beam affects the number of detectors installed.

When installing smoke and temperature detectors on the ceiling where the height of the A-beam protruding from the ceiling is less than 200mm, the impact on the protection area of the detector may not be considered.

When the height of the beam protruding from the ceiling is between 200mm and 600mm, the influence of the beam and the number of areas between the beams that can be protected by one detector should be determined according to Table 6-4.

When the height of the beam protruding from the ceiling exceeds 600mm, at least one detector should be installed in each inter beam area separated by the beam.

When the area separated by the beam exceeds the protection area of one detector, it should be considered as a detection area and the number of detectors should be calculated.

4.2.5 When there is a thermal barrier at the top of the house, the distance from the lower surface of the smoke detector to the ceiling should comply with the provisions in Table 6-5. Sawtooth shaped roofs and herringbone shaped roofs with a slope greater than 15 ° should have a row of detectors installed at each ridge. The distance between the lower surface of the detector and the highest point on the roof should comply with the provisions of Table 6-5.

4.2.6 The detector should be installed horizontally. If it is necessary to install it at an angle, the angle of inclination should not exceed 45 °.

4.2.7 The room is separated by bookshelves, equipment, or partitions, and the distance from the top to the ceiling or beam is less than the net height of the room

Table 6-4: Determine the number of beam to beam areas that a detector can protect based on the area between beams

The protection area of the detector A (m2) is the area between the beams of the beam partition Q (m2) is the number of beam areas protected by one detector