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)于罐(guan)(guan)內(nei)介質的(de)(de)溫度、壓力變化等原(yuan)因，儲(chu)(chu)罐(guan)(guan)不能完全(quan)裝滿，應(ying)留有一(yi)定的(de)(de)空間(jian)，而且液(ye)體儲(chu)(chu)罐(guan)(guan)工(gong)(gong)作(zuo)時(shi)液(ye)面允(yun)許有一(yi)個上下(xia)波(bo)動(dong)的(de)(de)范(fan)圍(wei)。這一(yi)上下(xia)波(bo)動(dong)范(fan)圍(wei)內(nei)的(de)(de)容(rong)(rong)量稱為工(gong)(gong)作(zuo)容(rong)(rong)量，儲(chu)(chu)罐(guan)(guan)實際允(yun)許儲(chu)(chu)存(cun)的(de)(de)最大(da)容(rong)(rong)量稱為儲(chu)(chu)存(cun)容(rong)(rong)量，所以，儲(chu)(chu)罐(guan)(guan)公稱容(rong)(rong)量最大(da)，工(gong)(gong)作(zuo)容(rong)(rong)量最小(xiao)，儲(chu)(chu)存(cun)容(rong)(rong)量居(ju)中。立式儲(chu)(chu)罐(guan)(guan)容(rong)(rong)量示意(yi)見圖12.3。液(ye)體儲(chu)(chu)罐(guan)(guan)工(gong)(gong)作(zuo)時(shi)，其實際存(cun)量不得(de)大(da)于儲(chu)(chu)存(cun)容(rong)(rong)量，也(ye)不得(de)小(xiao)于儲(chu)(chu)存(cun)容(rong)(rong)量減(jian)去工(gong)(gong)作(zuo)容(rong)(rong)量之差。