【 Weak current College 】 fire pump problems

Most fire water supply water of fire, the fire pump is required for compression to meet fire extinguishing water to water pressure and when. Pump maintenance due to incorrectly set, produce failure affect fire rescue, resulting in unnecessary loss. Here, the author for the work of several fire pump problem talk about personal understanding, to party home fuzheng.
1. multilayer construction is necessary to set special fire-fighting pump
The architectural design of the fire code (hereinafter referred to as buildings》) section 8.6.3 stipulates: "set up a temporary high pressure water supply system of the building, should fire water tank or air pressure tank, water tower". According to this provision, to set up a temporary high-pressure fire water supply system of the building, should set a fire water tank. This type of architecture is 4, 5-layer multilayer construction and municipal pipe pressure usually 20 to 30 m water column, to meet the most negative point fire hydrants required substantial water needs, this type of construction also should set the fire pump. However, the multilayer construction sets goal of indoor hydrant system is only used to extinguish the fire in the early days, a lot of work but also rely on the city of extinguishing the Fire Department, fire pumps for this setting is a bit of a waste. For this type of construction, I do not know whether you can draw on high-rise buildings in fire water tank outlet on turbocharging facilities in fire water tank of water pipe on the set to the button in the fire box, or by a fire water tank outlet flow indicator on the launch of a booster pump to meet the needs of the full water column. This is a booster pump located in the roof, is a light start, boot speed, to fight the fire should be favourable early.
In addition, in the municipal network to meet the indoor and outdoor fire water consumption, I wonder if you can consider building different purposes to determine whether to set the fire pump. The factory area and a large public building, promoting the establishment of fire pump to have some self-help in General residential, allows its not fire pumps, fire fire engines use pump adapter outdoors sprinkler, after all, even in residential buildings within the fire pump, residents may not necessarily correct use.
Second, the fire pump performance and test requirements
The fire pump and water pump life and production water pump performance should be compared to the high demand, but the current standard for fire pump performance and test requirements do not make more details of special provisions, resulting in the fire pump in the selection is not well documented, there are a variety of issues. United States NFPA20 on fire pump performance requirements are: fire control pump of maximum flow rate should be the design value of 150%, head of not less than the selected working point head of 65% off the lift when the pump is not larger than the selected working point lift 140%, voltage pump flow rate is 1 — 2L/S, head for the fire pump head of 1.1 — 1.2 times. At the same time requirements in the fire pump outlet should be located on the measurement of the flow meters, flow meter shall be able to test the flow of the pump selected 175%, fire pump shall be located on the outlet pipe diameter is greater than the pressure 89mm. Recommended clearance, the relevant departments of the reference standard for the United States fire pump design, selection of a more targeted, more specific requirements for the selection of fire pumps, detection process according to follow.
3. pump line laying
In many design drawings in discovery: the fire pump for distribution line, control line more wearing PVC pipe for protection, and the alignment from the ceiling. The author believes this alignment method defect. Although buildings》 only requires fire electricity equipment distribution line downlead wear metal pipe, not concealed metal pipe protection when worn, but the civil construction electrical design code (hereinafter referred to as the civil rules "), section: fire 24.8.5 linkage control, automatic fire extinguishing control line should be used in fire-retardant cable wear steel concealed without burning body structural layer, protective layer thickness of not less than 3cm, when must the downlead should adopt in metal pipes for fire prevention. The automatic fire alarm system design specifications "(hereinafter referred to as the automatic alarm code) first section 8.2.2 also make appropriate provision. We know that the fire pump on fire after a while still to play, to complete the building fire suppression work. So during this time, you still want to ensure the safety of the water line. For distribution, and electric shaft distance, fire-fighting appliances larger capacity, the line cannot be concealed, can take effective fire prevention measures laying in the ceiling. In this case you should avoid using fire-resistant tray because ceiling is fire-prone areas, laying in the ceiling in the line of fire is not secure, and Groove boxes only can prevent external combustion on line, could not prevent Groove box line fire caused by its own failure. Recommends that such important fire pumps, fire-resistant cable power supply of the equipment in order to ensure that fire when a certain period of time will not be affected to continue working.
IV. whether the fire pump shall be located overload protection
The fire pump is an important equipment fire rescue, fire-fighting plays an extremely important role. Follow our habitual thinking, where important equipment should set overload protection. But the civil rules of article 8.6.3.5, 10.2.2.4 (3) stipulates that: "suddenly causes than due to overload and damage larger distribution lines, not cut off the circuit should be installed for overload protection appliances (such as fire pump power supply line), but should be installed overload alarm appliances." According to this provision, the fire pump should be equipped with overload protection cutting device. This was mainly to take into account when the fire broke out, should be all-out guarantee fire water needs, because due to the pump overload can cause loss of transmission lines, equipment and fire loss negligible. But in engineering practice even in standard construction Atlas, including college textbooks described in the electrical diagram of fire pumps, fire pumps circuit still added overload protection off electrical appliances, such as the electric installation works Atlas JD13-318 pages "fire protection system voltage start fire pump control unit figure (2)". This clearly does not meet specifications.
5. fire pump control
(1) control voltage. The civil provisions governing law 24.6.2.1: located in the fire hydrant box in the button for starting the fire pump and Kai pump lights control loop should use 50V voltage safety below. Provisions of article 24.9.11: Fire fighting equipment for DC operation power supply 24V voltage should be used. This is mainly to prevent the use of fire hydrants, water overflowed the fire box and water, water gun live injury and fire fighters (this injury accident heard). But in the actual construction and some references in the fire hydrant button action power supply voltage is still received AC 220V, as previously mentioned the Atlas on the same page it made such an error.
(2) start control. Fire hydrant pump has three parts to control start. ① According buildings》 and the tall buildings design fire protection standard of requirements for indoor hydrant box office directly. ② the automatic alarm code requirements, fire control rooms and control. ③ in water pumping station, near the fire hydrant pump control. This should correct handling of the following two issues: first, you should correctly identify fire control rooms, fire hydrant button and fire pump control priority issues. In General should fire control room long-distance operation. But now authorities on long-distance operation does not have a clear guidance on standards, engineering practices, rationality and operation of it varies greatly. There's simply stops the pump button and/threaded to the second loop of a manual start and stop the pump button, simply remove the thermal relay, mostly in the pumping station control cabinet set manual/automatic transfer switch, normally placed in the location automatically. We believe that several methods have defective. Song goofy at the pump is designed for long-distance operation of "in the remote operation relay contacts across the switch section, directly from the main fire pump contactor coil circuit, fire pumps achieve started directly. We think the idea is good, both to resolve a problem directly, and easy to launch control room monitors, also meets the pumping station control cabinet is in any State to be able to start a fire pump over long distances. Second, determine what kind of fire pumps. As soon as the fire equipment working to reduce fire losses, taking into account the majority of the non-fire-fire load fire pumps have been cut off, should give priority to direct starting with full pressure.
(3) failure to control. According to the automatic alarm code section 4.2.1 requirements, fire control, fire-fighting equipment should be can't display the failed State. Due to technical issues, to power off, and so simple fault signal fire control can display, but on the other fault signal such as fire pump overload failure signal as the automatic alarm code, the civil rules are not clearly stated implementation approach, often avoid the construction of practical, affected the control room on device failure detected correctly.
(4) Manual alarm button instead of a fire hydrant button to restart the pump. Use the report fire hydrant hand instead of a fire hydrant button cycle pump in engineering practices is more popular, project uses double-contact button, a contact for hand reported, the alarm signal to the fire alarm controller and the other contact points for Kai pump button used to restart signal sent to the control of the pump room is double toggle box Kai pump. But according to section 8.6.2 buildings》 (9), the doctrine of 7.4.6.7: each hydrant Office should be located directly on the button to start the fire pump. But hand report button will cycle the pump is fire signal feedback to alarm linkage controller, after confirmation by the controller started the fire pump, and not directly to start the fire pump. Also, this place on automatic alarm system high demand. At present, due to the high rate of false positives of automatic alarm system and running cost, part of the construction of the automatic alarm system run under disease often do not even opened, it is difficult to play their proper role. Therefore, we believe, or not to promote hand report instead of a fire hydrant button to start the fire pump.
6. fire control pump of periodic maintenance
Although the specifications, regulations expressly require fire-fighting facilities and equipment should be regularly maintained, but the fire pump cannot be run regularly on the machine, forever lead pump body card die, die, and rust does not fire. October 25, Guangzhou daily, to the 50 million fire service facilities that drop out of the spout is not entitled to disclose the yuexiu district room3017 comprehensive market fire facilities due to lack of maintenance, fire does not run correctly, causing catastrophic losses. Therefore we suggest in the specification requirements in the fire pump in the programmable logic controller (PLC) controls the pump group, implement fire pump in the spare time to regularly test run, start automatically when I put out the fire, thereby effectively put an end to the fire pump critical time cannot be used.