儲罐的容量與其幾何尺寸有關。按鋼材耗量最小的原則，對大型的立式儲罐(guan)，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(you)于(yu)罐內(nei)介質的(de)溫度、壓力變(bian)化等原因，儲(chu)(chu)(chu)(chu)(chu)罐不(bu)(bu)能完全裝滿，應留有(you)(you)一定的(de)空間(jian)，而且液體(ti)儲(chu)(chu)(chu)(chu)(chu)罐工(gong)作(zuo)時液面允(yun)許有(you)(you)一個上下波(bo)動的(de)范(fan)圍(wei)。這一上下波(bo)動范(fan)圍(wei)內(nei)的(de)容(rong)(rong)量(liang)(liang)(liang)稱為工(gong)作(zuo)容(rong)(rong)量(liang)(liang)(liang)，儲(chu)(chu)(chu)(chu)(chu)罐實(shi)際允(yun)許儲(chu)(chu)(chu)(chu)(chu)存(cun)的(de)最(zui)大容(rong)(rong)量(liang)(liang)(liang)稱為儲(chu)(chu)(chu)(chu)(chu)存(cun)容(rong)(rong)量(liang)(liang)(liang)，所以，儲(chu)(chu)(chu)(chu)(chu)罐公稱容(rong)(rong)量(liang)(liang)(liang)最(zui)大，工(gong)作(zuo)容(rong)(rong)量(liang)(liang)(liang)最(zui)小，儲(chu)(chu)(chu)(chu)(chu)存(cun)容(rong)(rong)量(liang)(liang)(liang)居中。立式儲(chu)(chu)(chu)(chu)(chu)罐容(rong)(rong)量(liang)(liang)(liang)示意見圖12.3。液體(ti)儲(chu)(chu)(chu)(chu)(chu)罐工(gong)作(zuo)時，其實(shi)際存(cun)量(liang)(liang)(liang)不(bu)(bu)得(de)大于(yu)儲(chu)(chu)(chu)(chu)(chu)存(cun)容(rong)(rong)量(liang)(liang)(liang)，也不(bu)(bu)得(de)小于(yu)儲(chu)(chu)(chu)(chu)(chu)存(cun)容(rong)(rong)量(liang)(liang)(liang)減去工(gong)作(zuo)容(rong)(rong)量(liang)(liang)(liang)之差。