儲罐的容量與其幾何尺寸有關。按鋼材耗量最小的原則，對大型的立式儲(chu)罐，當公稱容量在1000～2000mm³時，取高度約等于直徑；對3000mm³以上的儲罐取高度等于3/8～3/4的直徑較為合理。儲罐的公稱容量是指按幾何尺寸計算所得的容量，向上或向下圓整后以整數表示的容量。

  由于罐(guan)內介質的(de)(de)(de)溫度(du)、壓力變化等原因(yin)，儲(chu)(chu)(chu)罐(guan)不能完全裝滿，應留有一定(ding)的(de)(de)(de)空間，而且液(ye)體儲(chu)(chu)(chu)罐(guan)工(gong)(gong)作(zuo)時液(ye)面允許有一個上下波動的(de)(de)(de)范圍。這(zhe)一上下波動范圍內的(de)(de)(de)容(rong)(rong)(rong)量(liang)(liang)稱(cheng)為工(gong)(gong)作(zuo)容(rong)(rong)(rong)量(liang)(liang)，儲(chu)(chu)(chu)罐(guan)實際允許儲(chu)(chu)(chu)存(cun)的(de)(de)(de)最大(da)容(rong)(rong)(rong)量(liang)(liang)稱(cheng)為儲(chu)(chu)(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)，所以，儲(chu)(chu)(chu)罐(guan)公稱(cheng)容(rong)(rong)(rong)量(liang)(liang)最大(da)，工(gong)(gong)作(zuo)容(rong)(rong)(rong)量(liang)(liang)最小，儲(chu)(chu)(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)居中。立式儲(chu)(chu)(chu)罐(guan)容(rong)(rong)(rong)量(liang)(liang)示意見(jian)圖(tu)12.3。液(ye)體儲(chu)(chu)(chu)罐(guan)工(gong)(gong)作(zuo)時，其實際存(cun)量(liang)(liang)不得(de)大(da)于儲(chu)(chu)(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)，也不得(de)小于儲(chu)(chu)(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)減(jian)去工(gong)(gong)作(zuo)容(rong)(rong)(rong)量(liang)(liang)之差。