Electric motors for fire pumps shall comply with NEMA MG-1 & NEMA Design B for three phase motors or NEMA Design N or L standard for single phase motors.
Electric pump overcurrent protection device shall be rated as sum of the following: 1- Locked rotor current of the largest pump motor. 2- The full load current of all of the other pump motors & accessory equipment
Fire tanks in high rise buildings in higher floors shall be equipped with automatic refill valves (Filling rate equals to fire fighting demand) supplied from a below floor fire pumps or a gravity feed tank.
When a water tank serves domestic & fire protection systems, domestic supply connection shall be connected above the level required for fire protection demand.
No any valve or fitting is allowed at Fire pump suction within a distance of 10 pipe diameter or (15.3m).Only OS&Y valves are allowed within this distance. - butterfly valves are not preferred in suction as it produces turbulence and water blockage.
- Fire pump rooms enclosing diesel engines either attached or separated from the building shall be protected by sprinkler system as extra Hazard group 2. - Fire pump rooms attached to buildings and enclosing electric driven Fire pumps shall be protected by sprinkler system as ordinary Hazard group 1.
Relief valve at pump discharge shall be installed if 121% of pump shut-off head (Churn pressure) + Available suction head ) Exceeds components rating (12 bar) maximum.
Pressure maintenance pump serves only aboveground piping for fire sprinkler and standpipe systems should be sized to provide a flow less than a single fire sprinkler or compensate leakage for 10 minutes or 1 gpm whichever is greater or 1% of system design flow.
Design area in density/area design method shall be revised in the following conditions: 1-If quick response sprinklers are used area should be revised according to figure 19.2.3.2.3.1 2- For sloped ceilings increase design area by 30%. 3-Dry pipe & double interlock preaction systems: increase design area by 30%. 4-If high temperature rating sprinklers are used area shall be reduced by 25%.
Minimum no of sprinklers in resdential buildings most remote area = 4 Spr , for combustible concealed spaces 8 sprinklers shall be considered in Hyd Calc.
Privacy curtains in healthcare facilities shall not be considered an obstruction if the following conditions are achieved 1-Curain has openings greater than 70% open. 2-Mesh extends a minimum of 22in. (550mm) down from ceiling.
Summary of standard upright/pendant sprinkler installation requirment: 1- Maximum distance between sprinklers 4.6m. 2- Maximum distance between sprinkler and wall equals to half the maximum distance between two sprinklers (2.3m). 3- Minimum distance between sprinkler and a wall 100mm to provide enough space for sprinkler element activation. 4- Minimum distance between sprinklers 1.8m to prevent cold soldering phenomenon, otherwise baffles shall be provided between sprinklers.
5- Maximum protection area per sprinkler is according to tables 10.2.4.2.1 (a),(b),(c),(d) 6-Distance between upright sprinkler deflector and ceiling 25mm to maximum of 12in (300mm)
If sprinklers with different temperature rating are installed in the same compartment, a phenomenon called skipping may occur which means sprinklers remote from fire will operate prior to sprinklers in the immediate vicinity.
Q: Is it mandatory to fill dry pipes after dry valve with compressed air or nitrogen? A: NFPA states it should be filled not mandatory as an additional step in a double interlock system, to allow the dry valve takes its signal from both detectors and air pressures inside pipes.
Air or nitrogen maximum pressure should be (1.4 bar) or 20 PSI in excess of water pressure. Minimum air pressure should be 0.3bar or (5 psi) higher than water pressure.
1- Gridded system shall not be used in dry pipe system. 2- Dry pipe systems maximum activation time is 60 Sec.if can not be accomplished system subdivision by check valves with auxiliary drain or by using multiple dry valves.
Mentioned information, that the maximum working pressure in piping system for components protection is 12 bar for aboveground piping only , for underground 10 bar is the maximum pressure
According to section 6.10.2.1.3, the minimum water velocity inside fire pipes for removing and flushing debris shall be a minimum of 10 ft/s (3 m/s) .No mention for the maximum expected velocity inside pipes.
Determining the ncessacity if sprinklers are required above false ceiling depends on components combstability, combustability assessment shall be determined according to NFPA 13, Ch 4 section 4.9
Based on ASTM standards E136 & E2965 to say material is limited combustible or non-combustible heat release rate shall not exceed 150 kw/m2 for 10 seconds or shall not exceed 8 MJ/m2.
Looped & gridded systems have an advantage of better hydraulic characteristics than tree systems .In contrast they are not preferred in dry & preaction systems due to the high time delay the water takes to reach to sprinklers.
As mentioned in NFPA 20, fire pump curve shall achieve 150% flow @ 65% head. For fire pumps listed for marine use, it should achieve 120% flow @ 65% head.
Commonly asked question, is it allowed to connect class ll fire department connection to sprinkler system? The answer is yes but should be provided with isolation valve connection in shore side buildings only. Not allowed for connection in marine systems or off-shore buildings, as it will deplete the sprinkler water demand more quickly.
الله ينور على حضرتك يا باشمهندس. بس انا شغال ان ال SPACING الموجودة في الكود هنا في حالة ال EXTENDED SIDE WALL انها هي المسافة يعني المسافة L . لكن المسافة على الجدار بتكون زي الستاندرد. وشفتها نفس الفكرة في مشاريع تانية
Also in NFPA 13, version 2022, sprinklers above ground piping shall be tested as following: A- Hydraustatic test: at 13.8 bar for 2 hours or 50 psi (3.4 bar) above static pressure in excess of 10.3 bar for 2 hours. B-Pneumatically: establish 40 psi pressure and measure drop, shall not exceed (0.1 bar) in 24 hours.
For storage application and in case of using in-rack sprinklers in combination with ceiling sprinklers, in rack sprinklers shall be provided with an independant zone control valve station from ceiling sprinklers zone control valve station.
Additional note from NFPA 13, for partially covered sprinklered buildings, demand of sprinklers shall be added to the requirements given in NFPA 14 (Allowance of landing valves and hose allowance)
