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。

  由于(yu)罐內介質(zhi)的(de)溫(wen)度(du)、壓力變(bian)化等原因(yin)，儲(chu)罐不(bu)(bu)能完(wan)全(quan)裝滿，應(ying)留有(you)一(yi)(yi)定的(de)空(kong)間，而且液(ye)體(ti)儲(chu)罐工(gong)(gong)作(zuo)時液(ye)面允(yun)許(xu)有(you)一(yi)(yi)個(ge)上下波動(dong)的(de)范(fan)圍(wei)。這一(yi)(yi)上下波動(dong)范(fan)圍(wei)內的(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)罐實(shi)際(ji)允(yun)許(xu)儲(chu)存(cun)的(de)最大(da)容(rong)(rong)(rong)量(liang)(liang)稱(cheng)為儲(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)，所(suo)以，儲(chu)罐公稱(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)存(cun)容(rong)(rong)(rong)量(liang)(liang)居中。立式儲(chu)罐容(rong)(rong)(rong)量(liang)(liang)示(shi)意見圖(tu)12.3。液(ye)體(ti)儲(chu)罐工(gong)(gong)作(zuo)時，其實(shi)際(ji)存(cun)量(liang)(liang)不(bu)(bu)得(de)(de)大(da)于(yu)儲(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)，也(ye)不(bu)(bu)得(de)(de)小于(yu)儲(chu)存(cun)容(rong)(rong)(rong)量(liang)(liang)減去工(gong)(gong)作(zuo)容(rong)(rong)(rong)量(liang)(liang)之差。