规格 端口标准 /mm 端口 /mm 底口标准 /mm 底口 /mm 中径(增加) /mm 管件端口标准 管件底口标准 20 19.25-19.35 19.26-19.29 19.55-19.65 19.57-19.64 19.36-19.39 19.0-19.5 18.8-19.3 25 24.25-24.35 24.25-24.33 24.55-24.65 24.56-24.64 24.26-24.40 23.8-24.4 23.5-24.1 32 31.15-31.25 31.10-31.24 31.50-31.60 31.54-31.66 31.24-31.31 30.7-31.3 30.4-31.0 40 39.07-39.23 39.04-39.21 39.47-39.63 39.54-39.64 39.18-39.45 38.7-39.3 38.3-38.9 50 48.97