Layout requirements and installation methods of fire water supply pipes and causes of water leakage
Dec 30, 2022
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Layout requirements and installation methods of fire water supply pipes and causes of water leakage
1. Requirements for outdoor fire pipeline layout
(1) When two-way fire water supply is used for outdoor fire water supply, ring pipe network should be used, but when one fire water supply is used, branch pipe network can be used.
(2) There are no less than 2 water inlet pipes delivering water to the ring pipe network, each of which can pass through the entire flow.
(3) Valves should be used to divide the circuit into separate parts. The number of outdoor fire hydrants in each section shall not exceed 5
(4) The diameter of the outdoor fire water supply pipe should not be less than DN100. When conditions permit, it should not be less than 150mm.
Pressure reducing valve setting
(1) A pressure relief valve should be installed before the inlet of the alarm valve. When connecting two or more alarm valves, a backup pressure reducing valve should be installed.
(2) A filter should be installed at the inlet of the pressure reducing valve, and the flow area should not be less than 4 times the cross-sectional area of the pipeline;
(3) The pressure gauge should be installed before and after the filter and pressure reducing valve. The diameter of the pressure gauge should not be less than 100mm, and the range should be twice the design pressure;
(4) The control valve should be installed before the filter and after the safety valve.
(5) After the pressure relief valve, a pressure test drain valve should be installed;
(6) The pressure reducing valve shall be equipped with a flow detection test interface or a flow meter;
(7) Pressure relief valves installed vertically shall flow downward.
(8) The proportional pressure reducing valve should be installed vertically, and the adjustable pressure reducing valve should be installed horizontally.
Indoor fire water supply pipeline
1. The following fire water supply pipe networks are circular:
(1) Supplying water to two or more buildings;
(2) Water is supplied to more than two water fire extinguishing systems;
(3) When using a temporary high-pressure fire water supply system with a high fire water tank;
(4) When supplying water to an automatic water fire extinguishing system controlled by two or more alarm valves.
A fire pump is a machine used to transport fire water. However, because some failures are prone to occur under different working conditions, the water leakage of the fire pump is one of them. There are both internal leakage and external leakage of fire pump water leakage, but any of them will affect the normal flow and lift of the fire pump.
First, it's easy to understand leaks. The leakage is that from the outside of the fire pump, it can be clearly seen that there is water leakage from the fire pump body. The location of the leakage is not fixed, but most of the leakage occurs on the mechanical seal, shaft seal and motor joints, even on the surface of the pump body. .
The internal leakage of the fire pump cannot be displayed, but its flow rate and lift are significantly reduced. However, whether it is internal leakage or external leakage is a fire pump failure, we need to identify it carefully and deal with it in time to prevent greater failures.
2. Causes and treatment methods of fire pump leakage
There are many reasons for fire pump leakage, including damage to the sealing surface, unevenness, loosening of bolts during installation, sand holes or cracks in the pump body, etc. Check the location of the fire pump leak to determine if there is a possibility of damage near it. For example, there is more leakage near the mechanical seal, so we can first judge the problem of the mechanical seal. If the pump body leaks, the pump body may have cracks.
After determining the cause of the leakage, the fire pump will be dismantled for further confirmation. If it's a sealing problem, you'll need to reseal and replace the gasket. When it is confirmed that there is a crack in the pump body, it should be replaced directly, and it is forbidden to continue to use it.
The reason for the internal leakage is mainly due to the damage of the check valve. In order to judge whether there is an internal crack, it is only necessary to stop the fire pump for a period of time, and then observe the pointer of the pressure gauge installed on the outlet pipe of the fire pump. You can accurately determine if the pump is leaking without changing it. If internal leakage is found, the seal of the check valve needs to be repaired or replaced with a new one.
1. Requirements for outdoor fire pipeline layout
(1) When two-way fire water supply is used for outdoor fire water supply, ring pipe network should be used, but when one fire water supply is used, branch pipe network can be used.
(2) There are no less than 2 water inlet pipes delivering water to the ring pipe network, each of which can pass through the entire flow.
(3) Valves should be used to divide the circuit into separate parts. The number of outdoor fire hydrants in each section shall not exceed 5
(4) The diameter of the outdoor fire water supply pipe should not be less than DN100. When conditions permit, it should not be less than 150mm.
Pressure reducing valve setting
(1) A pressure relief valve should be installed before the inlet of the alarm valve. When connecting two or more alarm valves, a backup pressure reducing valve should be installed.
(2) A filter should be installed at the inlet of the pressure reducing valve, and the flow area should not be less than 4 times the cross-sectional area of the pipeline;
(3) The pressure gauge should be installed before and after the filter and pressure reducing valve. The diameter of the pressure gauge should not be less than 100mm, and the range should be twice the design pressure;
(4) The control valve should be installed before the filter and after the safety valve.
(5) After the pressure relief valve, a pressure test drain valve should be installed;
(6) The pressure reducing valve shall be equipped with a flow detection test interface or a flow meter;
(7) Pressure relief valves installed vertically shall flow downward.
(8) The proportional pressure reducing valve should be installed vertically, and the adjustable pressure reducing valve should be installed horizontally.
Indoor fire water supply pipeline
1. The following fire water supply pipe networks are circular:
(1) Supplying water to two or more buildings;
(2) Water is supplied to more than two water fire extinguishing systems;
(3) When using a temporary high-pressure fire water supply system with a high fire water tank;
(4) When supplying water to an automatic water fire extinguishing system controlled by two or more alarm valves.
A fire pump is a machine used to transport fire water. However, because some failures are prone to occur under different working conditions, the water leakage of the fire pump is one of them. There are both internal leakage and external leakage of fire pump water leakage, but any of them will affect the normal flow and lift of the fire pump.
First, it's easy to understand leaks. The leakage is that from the outside of the fire pump, it can be clearly seen that there is water leakage from the fire pump body. The location of the leakage is not fixed, but most of the leakage occurs on the mechanical seal, shaft seal and motor joints, even on the surface of the pump body. .
The internal leakage of the fire pump cannot be displayed, but its flow rate and lift are significantly reduced. However, whether it is internal leakage or external leakage is a fire pump failure, we need to identify it carefully and deal with it in time to prevent greater failures.
2. Causes and treatment methods of fire pump leakage
There are many reasons for fire pump leakage, including damage to the sealing surface, unevenness, loosening of bolts during installation, sand holes or cracks in the pump body, etc. Check the location of the fire pump leak to determine if there is a possibility of damage near it. For example, there is more leakage near the mechanical seal, so we can first judge the problem of the mechanical seal. If the pump body leaks, the pump body may have cracks.
After determining the cause of the leakage, the fire pump will be dismantled for further confirmation. If it's a sealing problem, you'll need to reseal and replace the gasket. When it is confirmed that there is a crack in the pump body, it should be replaced directly, and it is forbidden to continue to use it.
The reason for the internal leakage is mainly due to the damage of the check valve. In order to judge whether there is an internal crack, it is only necessary to stop the fire pump for a period of time, and then observe the pointer of the pressure gauge installed on the outlet pipe of the fire pump. You can accurately determine if the pump is leaking without changing it. If internal leakage is found, the seal of the check valve needs to be repaired or replaced with a new one.
