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。

  由于罐內介質的(de)溫度(du)、壓力變化等原(yuan)因(yin)，儲(chu)(chu)(chu)罐不能完全裝滿(man)，應(ying)留(liu)有一定的(de)空(kong)間，而且液體儲(chu)(chu)(chu)罐工作時液面允(yun)許(xu)有一個上下波動的(de)范圍(wei)。這一上下波動范圍(wei)內的(de)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)稱為工作容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)，儲(chu)(chu)(chu)罐實(shi)際允(yun)許(xu)儲(chu)(chu)(chu)存的(de)最(zui)大容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)稱為儲(chu)(chu)(chu)存容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)，所以，儲(chu)(chu)(chu)罐公(gong)稱容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)最(zui)大，工作容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)最(zui)小，儲(chu)(chu)(chu)存容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)居中。立式(shi)儲(chu)(chu)(chu)罐容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)示意見圖12.3。液體儲(chu)(chu)(chu)罐工作時，其實(shi)際存量(liang)(liang)(liang)不得(de)大于儲(chu)(chu)(chu)存容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)，也不得(de)小于儲(chu)(chu)(chu)存容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)減(jian)去工作容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)之差。