在某石化裝置,浙江至德鋼業有限公司工人人員發現某氧(yang)氣(qi)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)不銹鋼管(guan)道(dao)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(jin)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。

如圖(tu)1.1.3所示,緊急(ji)切(qie)斷閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)(tong)常(chang)是(shi)自動(dong)的(de),在全開(kai)位置運(yun)行(xing)(xing),通(tong)(tong)(tong)(tong)(tong)常(chang)僅(jin)在緊急(ji)情況下關閉。緊急(ji)切(qie)斷閥(fa)(fa)(fa)(fa)是(shi)高流(liu)量閥(fa)(fa)(fa)(fa),通(tong)(tong)(tong)(tong)(tong)常(chang)為(wei)閘閥(fa)(fa)(fa)(fa)、刀(dao)形閘閥(fa)(fa)(fa)(fa)、蝶(die)閥(fa)(fa)(fa)(fa)或球閥(fa)(fa)(fa)(fa)。旁(pang)通(tong)(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)(tong)常(chang)是(shi)從手動(dong)閥(fa)(fa)(fa)(fa)的(de)上游到下游的(de)隔離閥(fa)(fa)(fa)(fa),安(an)裝(zhuang)目的(de)是(shi)通(tong)(tong)(tong)(tong)(tong)過隔離閥(fa)(fa)(fa)(fa)對壓(ya)(ya)(ya)力(li)進(jin)行(xing)(xing)均衡,一(yi)旦建立了壓(ya)(ya)(ya)力(li)均衡,隔離閥(fa)(fa)(fa)(fa)可(ke)以(yi)安(an)全打開(kai)。旁(pang)通(tong)(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)也用(yong)于(yu)對下游系統(tong)緩(huan)慢加壓(ya)(ya)(ya),以(yi)緩(huan)解超速(su)和快速(su)增(zeng)壓(ya)(ya)(ya)風險。受控、緩(huan)慢加壓(ya)(ya)(ya)需要(yao)使用(yong)節(jie)(jie)流(liu)流(liu)量控制(zhi)型(xing)閥(fa)(fa)(fa)(fa)門(men),由(you)于(yu)其具有(you)流(liu)量控制(zhi)功能,旁(pang)通(tong)(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)分為(wei)節(jie)(jie)流(liu)閥(fa)(fa)(fa)(fa)、過程(cheng)控制(zhi)閥(fa)(fa)(fa)(fa)。雖然被歸類為(wei)過程(cheng)控制(zhi)閥(fa)(fa)(fa)(fa),旁(pang)通(tong)(tong)(tong)(tong)(tong)閥(fa)(fa)(fa)(fa)通(tong)(tong)(tong)(tong)(tong)常(chang)為(wei)手動(dong)操作(zuo)閥(fa)(fa)(fa)(fa),通(tong)(tong)(tong)(tong)(tong)常(chang)是(shi)截(jie)止閥(fa)(fa)(fa)(fa)或球閥(fa)(fa)(fa)(fa)等。為(wei)盡量減(jian)少旁(pang)通(tong)(tong)(tong)(tong)(tong)管(guan)線(xian)中可(ke)能聚集的(de)顆粒數量,旁(pang)通(tong)(tong)(tong)(tong)(tong)管(guan)連接(jie)應(ying)安(an)裝(zhuang)到主管(guan)中心線(xian)或中心線(xian)以(yi)上。
按GB 50030《氧氣(qi)站設計(ji)規范》,設計(ji)壓力(li)大于(yu)0.1MPa的(de)氧氣(qi)管道上(shang),不得用閘閥(fa)。設計(ji)壓力(li)大于(yu)或(huo)(huo)等于(yu)1.0MPa且公稱直徑大于(yu)或(huo)(huo)等于(yu)150mm的(de)氧氣(qi)管道上(shang)的(de)手(shou)動閥(fa)門(men),宜設旁通閥(fa)。設計(ji)壓力(li)大于(yu)1.0MPa,公稱直徑大于(yu)或(huo)(huo)等于(yu)150mm的(de)氧氣(qi)管道上(shang)經常操(cao)作(zuo)的(de)閥(fa)門(men),宜用氣(qi)動閥(fa)門(men)。

