浮頂油罐上部是敞開的，罐(guan)頂只是漂浮在罐內油面上隨油面的升降而升降的浮盤，浮盤外徑比罐壁內徑小400～600mm，用以裝設密封裝置，以防止這一環狀間隙中的油品產生蒸發損壞，同時防止風沙雨雪等污染油品。密封裝置形式很多，常用的有彈性填料密封或管式密封。

  浮頂(ding)(ding)(ding)油(you)(you)(you)(you)罐(guan)(guan)(guan)(guan)當(dang)罐(guan)(guan)(guan)(guan)頂(ding)(ding)(ding)隨油(you)(you)(you)(you)面下降至罐(guan)(guan)(guan)(guan)底時，油(you)(you)(you)(you)罐(guan)(guan)(guan)(guan)就變為上部(bu)(bu)敞開的(de)(de)立(li)式圓筒(tong)形(xing)容器，若(ruo)此(ci)(ci)時遇大風，罐(guan)(guan)(guan)(guan)內易形(xing)成(cheng)真(zhen)空(kong)(kong)，如真(zhen)空(kong)(kong)度(du)過大罐(guan)(guan)(guan)(guan)壁有(you)可能(neng)被(bei)壓癟，為此(ci)(ci)在靠近(jin)頂(ding)(ding)(ding)部(bu)(bu)的(de)(de)外側設置抗風圈。由于(yu)罐(guan)(guan)(guan)(guan)頂(ding)(ding)(ding)在罐(guan)(guan)(guan)(guan)內上下浮動，故罐(guan)(guan)(guan)(guan)壁板只能(neng)采(cai)用(yong)對接焊接并(bing)且內壁要取平。浮頂(ding)(ding)(ding)油(you)(you)(you)(you)罐(guan)(guan)(guan)(guan)罐(guan)(guan)(guan)(guan)頂(ding)(ding)(ding)與(yu)油(you)(you)(you)(you)面之(zhi)間基本上沒有(you)氣(qi)相空(kong)(kong)間，油(you)(you)(you)(you)品沒有(you)蒸發(fa)(fa)的(de)(de)條件，因(yin)(yin)而沒有(you)因(yin)(yin)環境溫度(du)變化(hua)而產生(sheng)的(de)(de)油(you)(you)(you)(you)品損耗(hao)，也基本上消除(chu)了(le)因(yin)(yin)收、發(fa)(fa)油(you)(you)(you)(you)而產生(sheng)的(de)(de)損耗(hao)，避免污染環境，減(jian)少(shao)發(fa)(fa)生(sheng)火災的(de)(de)危險性。所以盡管(guan)這種油(you)(you)(you)(you)罐(guan)(guan)(guan)(guan)鋼材(cai)耗(hao)量(liang)和安裝費用(yong)比拱頂(ding)(ding)(ding)油(you)(you)(you)(you)罐(guan)(guan)(guan)(guan)大得多，但(dan)對收發(fa)(fa)油(you)(you)(you)(you)頻繁的(de)(de)油(you)(you)(you)(you)庫、煉油(you)(you)(you)(you)廠原油(you)(you)(you)(you)區等仍(reng)應優先(xian)選用(yong)，用(yong)于(yu)儲(chu)存原油(you)(you)(you)(you)、汽油(you)(you)(you)(you)及其他揮發(fa)(fa)性油(you)(you)(you)(you)品。

  浮(fu)(fu)頂(ding)(ding)罐的(de)種(zhong)類(lei)很多，有(you)(you)(you)單(dan)盤(pan)式(shi)(shi)(shi)、雙盤(pan)式(shi)(shi)(shi)、浮(fu)(fu)子式(shi)(shi)(shi)等。常用的(de)單(dan)盤(pan)式(shi)(shi)(shi)浮(fu)(fu)頂(ding)(ding)罐在浮(fu)(fu)頂(ding)(ding)周圍(wei)建(jian)造(zao)環(huan)形(xing)浮(fu)(fu)船(chuan)，用隔(ge)(ge)板將浮(fu)(fu)船(chuan)分隔(ge)(ge)成若干個不滲漏(lou)的(de)船(chuan)室(shi)，在環(huan)形(xing)浮(fu)(fu)船(chuan)范圍(wei)內的(de)面積以單(dan)層金屬(shu)板覆蓋。而(er)雙盤(pan)式(shi)(shi)(shi)浮(fu)(fu)頂(ding)(ding)罐的(de)浮(fu)(fu)頂(ding)(ding)則(ze)是上、下兩(liang)面分別以金屬(shu)板覆蓋。不論(lun)是單(dan)盤(pan)浮(fu)(fu)頂(ding)(ding)罐還是雙盤(pan)浮(fu)(fu)頂(ding)(ding)罐，浮(fu)(fu)盤(pan)上面都安(an)裝有(you)(you)(you)梯子、平(ping)臺(tai)和(he)欄桿。建(jian)造(zao)浮(fu)(fu)頂(ding)(ding)的(de)金屬(shu)材料有(you)(you)(you)碳(tan)鋼和(he)鋁合(he)金兩(liang)種(zhong)，目前，碳(tan)鋼材料的(de)浮(fu)(fu)頂(ding)(ding)已逐(zhu)漸被鋁合(he)金浮(fu)(fu)頂(ding)(ding)所(suo)替代。浮(fu)(fu)頂(ding)(ding)一(yi)般在專門的(de)制造(zao)廠建(jian)造(zao)，作為(wei)成品部件供貨。