减压孔板快速计算书

1、减压孔板在室内给排水工程中，减压孔板可用于消除给水龙头和消火栓前的剩余水头，以保证水 系统均衡供水，达到节水、节能的目的。(1) 减压孔板孔径的计算：水流通过孔板式的水头损失，按式中计算：2H = E (lOa)2 呂1 式4式中H水流通过孔板的水头损失值(10 Pa)：一一孔板的局部阻力系数；U水流通过孔板后的流速(m/s)：g-重力加速度(m/s)a纟值可从下列式中求得：D2 -1II防2 式式屮 D 给水借道直径(mm )；d扎板孔径(mm )为简化计算，将各种不同管径及孔板孔径代入公式 1 式、2 式，求得相应的 H 值，所得讣算结果列于表 1 使用时，只要已知剩余水头1 及给水立管直

2、径 D,九可从表中査的所需 孔板孔径 d。表 1:减压孔板的水头损失D(mm)d(mm)3456789101112131581.0324.549.494.252.091.100.590.330.180.090.0420262.3081.0332.1614.917.684.252.481.510.940.590.3825201.7781.0338.1319.9811.316.794.252.751.831.2432222.21105.5956.0032.1619.6112.538.305.673.9640262.30140.0281.0349.8432.1621.5614.9110.585020

3、1.77124.8081.0354.7038.1327.30Dd(mm)(mm)1402122232420250.240.860.150.590.090.420.050.290.030.200.010.140.090.060.040.020.01322.832.051.511.120.840.630.470.360.270.200.15407.685.674.523.232.481.921.511.180.940.750.595019.9814.9111.318.716.795.344.253.412.752.241.837081.0360.9846.6936.3028.5922.781835

4、14.9112.2210.108.4080140.82105.5981.0363.1349.8439.8332.1626.2221.5617.8714.91100201.77157.61124.80100.0281.0366.2854.7045.5038.13Dd(mm)(mm)252627282930313233320.110.080.060.040.020.01400.470.380.300.240.190.150.120.090.07501.511.241.030.850.710.590.500.420.35707.035.915.004.253.633.112.672.311.9980

5、12.5310.588.997.606.585.674.904.253.7010032.1627.3023.2919.9817.2314.9112.9711.319.9112581.0468.9959.0750.7443.8938.1433.2829.1025.59150170.85145.60124.80107.5493.1381.0370.8062.1154.70D(mm)343536373839404142400.050.040.030.020.01500.290.240.200.170.140.010.090.080.06701.731.511.311.151.000.880.770.

6、680.59803.232.832.482.181.921.701.511.331.181008.717.686.796.015.344.764.253.803.4112522.5920.0017.7215.7914.1012.6011.3110.189.1615048.3442.8738.1334.0230.4327.3024.5422.1219.90Dd(mm)(mm)434445464748495051500.050.040.030.020.010.01700.520.460.400.360.310.280.240.210.19801.050.940.840.750.670.580.53

7、0.470.421003.062.752.482.242.021.831.661.511.371258.287.496.786.155.595.104.664.253.9015018.0916.4114.9113.5812.3811.3110359.498.71Dd(mm)(mm)525354555657585960700.160.140.120.110.090.080.070.060.05800.380.340.300.270.240.220.190.170.151001.241.131.030.940.860.780.710.650.591253.563.273.002.762.532.3

8、42.151.981.831508.007.366.796.265.785.344.954.584.25D(mm)d(mm)616263646566676869700.040.030.030.020.020.010.01800.140.120.110.090.080.070.060.050.051000.540.500.450.420.380.350.320.290.271251.691.561.451.341.241.151.070.990.921503.953.673.413.172.952.752.572.402.24Dd(mm)(mm)7767778800.040.030.030.02

9、0.020.010.010.011000.240.220.200.180.170.150.140.130.111250.850.790.740.690.640.590.550.510.481502.091.961.831.711.611.511.411.321.24Dd(mm)(mm)79808871000.100.090.080.080.070.060.050.050.041250.450.410.390.360.330.310.290.270.251501.171.101.030.970.910.860.800.760.71Dd(mm)(mm)88899961000.040.030.030

10、.020.020.010.010.010.011250.230.220.200.190.170.160.150.140.131500.670.630.590.560.530.500.470.440.42Dd(mm)(mm)97989911041051250.120.110.100.090.090.080.070.070.061500.390.370.350.330.310.290.270.260.24Dd(mm)(mm)111141250.050.050.040.040.040.030.030.020.021500.230.210.200.190.180.170.160.150.14Dd(mm)(mm)11191201211221231250.020.010.010.010.010.011500.130.120.110.110.100.090.090.08注：表中给水管计算管径均采用公称直径表 1 中数据是假眾水流通过孔板后的流速为 lm/s 时讣算得岀的，如实际流速与此不符，则 应按式 3 进行修正，并安修正后的剩余水头查表。H4= * 1 （lOTa）”3 式llOl4Pcl式中1 一一修正后的剩余水头（：U一水流通过孔板后的实际流速（m/s）：llOlPallH一设计剩余水头（【例】已知给水干管管径