Item:
SGCC 150g DX51D+Z Hot Dipped Metal Iron Galvanized Steel Coil
Material:
SGCC, SGCH, SPCC, SGCD, DX51D+Z, STO2Z,DX54D,DX51D
Thickness:
0.1 2 mm-3mm
Width:
600-1250mm
Length:
Coiled or as requested
Surface:
Galvanized,oiled, chromated
Application:
Industrial panels, roofing and siding for painting
Types:
Commercial / Drawing / Deep Drawing / Structural quality
Zinc coating:
Z 3 0-275g/m2
Surface Treatment:
chromed / skinpass/ oiled/slightly oiled/ dry/ anti-fingerprint
Surface Structure:
zero spangle / minimized spangle / regular spangle/ big spangle
Coil Weight:
3-10 ton per coil
Payment term:
T/T,L/C
Packing information:
Standard seaworthy export packing: 3 layers of packing, inside is kraft paper, water plastic film is in the middle and outside GI steel sheet to be covered by steel strips with lock, with inner coil sleeve.
Port:
Qingdao,Tianjin port
Delivery time:
15-20 days,after we received your deposit
GI,GI Steel Coil,GI Steel Sheet,Galvanized Steel Coil,Zinc Coated Steel Coil Jinan Hengming Steel Co., Ltd , https://www.jnhengmingsteel.com
How to Design Pressure Relief Valve in Fire Protection System
How to design the relief valve in the fire protection system? First, the role of relief valve set in the fire pump outlet pipe, usually closed, the fire hose pressure exceeds the set value automatically opens to prevent damage to the water supply system due to overpressure. Second, why overpressure fire water supply pipe overpressure mainly due to the following reasons: ①press the fire design flow selection of the pump flow? Head curve is steep (ordinary fire pump non-fire tangent pump), in the low-flow operation (Self-test or early fire) will occur overpressure; ② pump suddenly for some reason (such as power outage) stalls, the outlet pipe has not taken the appropriate technical measures to stop pumping caused by over-pressure water hammer. Third, the design details Relief valve settings should pay attention to the location, caliber selection, pressure settings and the corresponding attachment configuration and other issues. ①relief valve can be located near the fire pump or fire water tank. Discharge should be connected to the fire pool. When the relief valve is set on the outlet pipe of the fire pump, it can eliminate the overpressure caused by the low flow operation of the pump before the check valve. After the check valve (along the flow direction) Overpressure caused by the operation, but also to eliminate over-pressure caused by the stop pump water hammer, even if the fire pump outlet pipe did not take other measures to eliminate the stop water hammer (speed closed check valve, slow closing check valve, Buffer tank, etc.), will not cause harm and loss. In the national standard Atlas is used in the pump set to take over the trunk pipe. Specific reference 04S204P9. ② Pressure relief valve caliber has two kinds of practices, one is with the fire water mains with the same diameter or smaller, and the other is the use of DN100 or DN150 pressure relief valve. From the pressure relief point of view, the larger the pressure relief valve pressure relief faster, the better. However, from an economic point of view, the larger the caliber, the higher the price of the pressure relief valve. Therefore, from a practical point of view, it is recommended to use a fixed-caliber pressure relief valve, even though the actual pressure will be slightly larger than the pressure relief of the large caliber pressure relief valve Pressure value, but the combined effect is still feasible. Therefore, the relief valve caliber can be selected as follows: If the fire water main pipe diameter D ≤ 150mm, the use of DN100 pressure relief valve; if the fire water supply pipe diameter D> 150mm, the use of DN150 pressure relief valve. ③ relief valve pressure setting should be higher than the main fire pump and pump pressure settings. When there is a regulator pump, there are two pressure values ​​for the regulator pump on and off (refer to the pressure value when the regulator pump is running). Stabilization pump stop pump water hammer pressure easily lead to pressure relief valve open, so for a stable high-pressure fire water supply system should have sound and reliable technical measures to eliminate stop pumping water hammer, and should review the fire water pipes in the water hammer produced Residual pressure, pressure relief valve below the pressure set value, to ensure that does not open by mistake. Generally higher than this pressure 5 to 10 meters. ④ pressure relief valve should be set in the branch pipe and fire water supply pipe connection. (For details, please refer to 04S204P9.) In order to facilitate the relief valve overhaul and to prevent the control valve from being closed, a signal valve or signal butterfly valve should be provided in front of the relief valve.