给水管材的选择：1.首先判断介质特性热水//////冷水热水1根据管材的使用环境（条件）分级2再根据设计压力PD选择管材S系列冷水直接根据管材公称压力PN选择管材S系列注意：不管冷热水因条件变化管材工作压力PS；设计压力PD；公称压力PN之间有个调整系数mPD=0.7PNPS=0.6~0.8PD?????给水管网的水利计算——————管径、水力损失、管网所需压力给水管网的水利计算的前提是：已知设计秒流量管径的确定：由水在管道内的经济流速确定生活给水管道的水流速度工程直径（ｍｍ）１５～２０２５～４０５０～７０≧８０水流速度（ｍ∕ｓ）≤１．０≤１．２≤１．５≤１．８工程设计中可采用下列数值：ＤＮ１５～ＤＮ２０，ｖ＝０．６～１．０ｍ∕ｓ；ＤＮ２５～ＤＮ４０，ｖ＝０．８～１．２ｍ∕ｓ；ＤＮ５０～ＤＮ７０；ｖ≤１．５ｍ∕ｓ；ＤＮ８０及以上的管径，ｖ≤１．８ｍ∕ｓ。给水管道水力计算的标准以一个给水龙头的用水流量0.2L/S，为一个当量。给水钢管水利计算表管径mm流量L/s流速m/sikpa/m0.2L/S一个当量同时使用水龙头量ＤＮ１５流速0.6~1m/s0.100.580.9850.181.052.911ＤＮ２０流速0.6~1m/s0.180.560.6010.351.092.042ＤＮ２５流速0.8~1.2m/s0.400.750.7480.651.221.854ＤＮ３２流速0.8~1.2m/s0.750.790.561.201.271.356ＤＮ４０流速0.8~1.2m/s0.950.760.431.601.271.148ＤＮ５０流速≤1.5m/s1.800.850.3783.51.651.3617.5ＤＮ７０流速≤1.5m/s3.00.850.2745.51.560.87527.5ＤＮ８０流速≤1.8m/s4.50.910.2469.01.810.94645ＤＮ１００流速≤1.8m/s9.01.040.22116.01.850.68580给水塑料管水利计算表管径mm流量L/s流速m/sikpa/m0.2L/S一个当量同时使用水龙头量Ｄｅ２０ＤＮ１５流速0.6~1m/s0.100.500.2750.200.990.9401Ｄｅ２５ＤＮ２０流速0.6~1m/s0.200.530.2360.401.050.7032Ｄｅ３２ＤＮ２５流速0.8~1.2m/s0.500.760.2790.801.210.6434Ｄｅ４０ＤＮ３２流速0.8~1.2m/s0.800.790.2291.501.470.6987.5Ｄｅ５０ＤＮ４０流速0.8~1.2m/s1.500.900.2172.001.200.36110Ｄｅ６３ＤＮ５０流速≤1.5m/s2.500.950.5174.001.510.40820Ｄｅ75ＤＮ65流速≤1.5m/s4.001.040.1666.001.560.34230Ｄｅ９０ＤＮ８０流速≤1.8m/s7.501.350.21310.001.800.35450Ｄｅ１１０ＤＮ１００流速≤1.8m/s7.500.900.0810.001.200.1350PVC-U（De）与公称直径（DN）对照表公称直径（DN）5075100150塑料管（De）5075110160200225250315355400查给排水课本第五版塑料管的管径流量表为什么用公称直径（DN）来表达？？？？？给水钢管水利计算表管径流量L/s流速immｍ∕ｓkpa/m０．１０0.580.985０．１２0.701.37ＤＮ１５０．１４0.821.82０．１６0.942.34０．１８1.052.91ＤＮ２０0.180.560.6010.200.620.720.250.781.090.300.931.530.351.092.04ＤＮ２５0.400.750.7480.450.850.9320.500.941.130.551.041.350.601.131.590.651.221.85ＤＮ３２0.750.790.560.800.840.630.850.900.700.900.950.780.951.000.861.001.050.951.101.161.141.201.271.35ＤＮ４０0.950.760.431.000.800.471.100.870.561.200.950.661.301.030.761.401.110.881.501.191.011.601.271.14ＤＮ５０1.800.850.3781.900.890.4182.00.940.4602.21.040.5492.41.130.6452.61.220.7492.81.320.8693.01.410.9983.51.651.36ＤＮ７０3.00.850.2743.50.990.3654.01.130.4684.51.280.5865.01.420.7235.51.560.875ＤＮ８０4.50.910.2465.01.010.305.51.110.3586.01.210.4216.51.310.4947.01.410.5737.51.510.65708.01.610.7488.51.710.8449.01.810.946ＤＮ１００9.01.040.2219.51.1010.01.1510.51.2111.01.2711.51.3312.01.3912.51.4413.01.5014.01.6215.01.730.60216.01.850.685给水管网水利计算表计算管段编号当量总数Ng同时出流概率Ｕ（％）设计秒流量（L/s）管径ＤＮmm流速（m/s）每米官场严惩水头损失ｉkpa/m管段长Lm管段沿程水头损失hy=iLkpa管段沿程水头损失累计kpa此为住宅生活给水水利计算其中同时出流概率Ｕ（％）的计算要注意顺序编号管段编号卫生器具卫生器具名称＼数量＼当量当量总数设计秒流量q(L/s)DNmmVm/s单阻Ikpa管长m沿程水头损失hy=iLkpa备...
