The calculation formulas for drain valve and vent valve in long drainpipe are approached, and the valve diameters are calculated being compared with the result in some literature.

• 探讨了热水管网放水阀、放气阀直径的计算公式,计算了长放水管放水阀直径,并与文献中短放水管放水阀直径进行了比较。