这里应该是额外的附加阻力系数,默认是不填的
根据输入值计算系统阻力系数,这个可附加。
下面是help说明
Supply the necessary k-factor value if you desire to include a fitting in the pipe unit. The k-factor is defined as the total resistance coefficient for the fitting, including allowances for multiple fittings, valves, and exit losses. This field is not available when line sizing calculation is selected.