在某石化裝置,浙江至德鋼業有限公司工人人員發現某氧氣管道閥門側面還設計了防爆操作防護墻,有些防護過度。歸根結底是配管設計人員沒有真正理解標準規范的設計要求,由心中過度害怕引起。如圖1.1.3所示,某氧氣管道主管是18”的A312 TP304/TP304L(SMLS),后增加了旁路,配管設計人員仍選用A312 TP304/TP304L(SMLS)不銹(xiu)鋼管道是錯誤的,因按照此工藝圖,旁路1.5"的流速加大了,需要選用鎳基合金材料(UNS N06600)才可以滿足工程設計質量。氧氣管道材料應根據管道壓力、溫度和流速不同選用碳鋼、不銹(xiu)鋼和鎳基合金;宜采用無縫鋼管、無縫管件、全通徑閥,其操作狀態全開或全關,不得使其處于半開半關狀態;切斷閥操作過程兩端壓差不能過大,閥門宜用法蘭連接;墊片宜選用帶內環聚四氟乙烯纏繞墊片;填料不應采用易脫落碎屑、纖維的材料或可燃的材料制成,宜選用聚四氟乙烯材料;三通宜選用等徑三通,氧氣管子、管件、閥門等應進行脫脂處理。見歐洲工業氣體協會標準(EIGA)《Oxygen Piping Systems》(氧氣管道系統)IGC DOC 13/12/E等規范。


3.jpg

  如圖1.1.3所示,緊(jin)急(ji)切(qie)斷閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)常(chang)是(shi)(shi)自動(dong)(dong)的(de)(de),在全(quan)開位置(zhi)運行(xing),通(tong)(tong)(tong)(tong)常(chang)僅在緊(jin)急(ji)情況下關閉(bi)。緊(jin)急(ji)切(qie)斷閥(fa)(fa)(fa)(fa)是(shi)(shi)高流(liu)(liu)量(liang)閥(fa)(fa)(fa)(fa),通(tong)(tong)(tong)(tong)常(chang)為閘(zha)閥(fa)(fa)(fa)(fa)、刀形(xing)閘(zha)閥(fa)(fa)(fa)(fa)、蝶閥(fa)(fa)(fa)(fa)或球閥(fa)(fa)(fa)(fa)。旁(pang)通(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)常(chang)是(shi)(shi)從手動(dong)(dong)閥(fa)(fa)(fa)(fa)的(de)(de)上(shang)游到(dao)下游的(de)(de)隔(ge)離(li)閥(fa)(fa)(fa)(fa),安(an)裝(zhuang)目的(de)(de)是(shi)(shi)通(tong)(tong)(tong)(tong)過隔(ge)離(li)閥(fa)(fa)(fa)(fa)對(dui)壓(ya)(ya)力進行(xing)均(jun)衡,一旦建立了壓(ya)(ya)力均(jun)衡,隔(ge)離(li)閥(fa)(fa)(fa)(fa)可(ke)以安(an)全(quan)打開。旁(pang)通(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)也用(yong)于對(dui)下游系統緩慢加(jia)壓(ya)(ya),以緩解(jie)超速和快速增(zeng)壓(ya)(ya)風險。受控(kong)(kong)、緩慢加(jia)壓(ya)(ya)需(xu)要使用(yong)節流(liu)(liu)流(liu)(liu)量(liang)控(kong)(kong)制(zhi)型閥(fa)(fa)(fa)(fa)門(men),由于其具(ju)有流(liu)(liu)量(liang)控(kong)(kong)制(zhi)功(gong)能(neng),旁(pang)通(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)分為節流(liu)(liu)閥(fa)(fa)(fa)(fa)、過程控(kong)(kong)制(zhi)閥(fa)(fa)(fa)(fa)。雖(sui)然(ran)被歸類為過程控(kong)(kong)制(zhi)閥(fa)(fa)(fa)(fa),旁(pang)通(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)常(chang)為手動(dong)(dong)操作閥(fa)(fa)(fa)(fa),通(tong)(tong)(tong)(tong)常(chang)是(shi)(shi)截止閥(fa)(fa)(fa)(fa)或球閥(fa)(fa)(fa)(fa)等。為盡量(liang)減少旁(pang)通(tong)(tong)(tong)(tong)管線(xian)中(zhong)可(ke)能(neng)聚集的(de)(de)顆粒數量(liang),旁(pang)通(tong)(tong)(tong)(tong)管連接應(ying)安(an)裝(zhuang)到(dao)主管中(zhong)心(xin)線(xian)或中(zhong)心(xin)線(xian)以上(shang)。


  按GB 50030《氧氣站設計規范》,設計壓(ya)力(li)(li)大于(yu)0.1MPa的(de)(de)氧氣管(guan)道(dao)上(shang),不得用(yong)閘閥。設計壓(ya)力(li)(li)大于(yu)或等(deng)(deng)于(yu)1.0MPa且公(gong)稱(cheng)直徑大于(yu)或等(deng)(deng)于(yu)150mm的(de)(de)氧氣管(guan)道(dao)上(shang)的(de)(de)手動閥門,宜設旁通閥。設計壓(ya)力(li)(li)大于(yu)1.0MPa,公(gong)稱(cheng)直徑大于(yu)或等(deng)(deng)于(yu)150mm的(de)(de)氧氣管(guan)道(dao)上(shang)經常(chang)操作的(de)(de)閥門,宜用(yong)氣動閥門。