盲(mang)板(ban)(ban)（Blind）、8字(zi)(zi)盲(mang)板(ban)(ban)（Spectacle Blind； Figure 8 Blind）、插板(ban)(ban)（Paddle Blank）以及墊環(huan)（Paddle Spacer），制(zhi)造(zao)方(fang)法一般(ban)分三(san)種(zhong)：鍛(duan)(duan)打(da)、鑄鍛(duan)(duan)、中板(ban)(ban)割制(zhi)。其中鍛(duan)(duan)打(da)產品價(jia)格最高，中板(ban)(ban)次(ci)之(zhi)，鑄鍛(duan)(duan)最低(di)。而(er)(er)質量是鍛(duan)(duan)打(da)和中板(ban)(ban)的(de)好，鑄鍛(duan)(duan)的(de)要(yao)稍差些。盲(mang)板(ban)(ban)或“8”字(zi)(zi)盲(mang)板(ban)(ban)與(yu)閥門相(xiang)比，其關斷(duan)作用(yong)更可(ke)靠而(er)(er)且更經濟。


  盲板(ban)(ban)、“8”字盲板(ban)(ban)、插板(ban)(ban)以及墊(dian)環都應有兩個和匹配法蘭同樣的密(mi)封面(mian)。常用的密(mi)封面(mian)包含平面(mian)、凹凸面(mian)、榫(sun)槽(cao)面(mian)和環連面(mian)。


  盲板（見(jian)圖4-15）用(yong)于(yu)起隔離、切斷作(zuo)用(yong)的(de)(de)，和(he)封頭、管帽所起的(de)(de)作(zuo)用(yong)是(shi)(shi)一(yi)(yi)樣(yang)的(de)(de)。由于(yu)其密封性能(neng)好，對于(yu)需要(yao)完(wan)全(quan)隔離的(de)(de)系統，一(yi)(yi)般都(dou)作(zuo)為可靠的(de)(de)隔離手段。盲板就(jiu)是(shi)(shi)一(yi)(yi)個(ge)帶柄的(de)(de)實心的(de)(de)圓，用(yong)于(yu)通常狀況下處于(yu)隔離狀態的(de)(de)系統。盲板的(de)(de)有關標(biao)準，可參見(jian)HG/T 20592～20635《鋼制管法(fa)(fa)蘭、墊片(pian)、緊固件》和(he)ASME B16.5《管法(fa)(fa)蘭和(he)法(fa)(fa)蘭管件》。


圖 15.jpg


  8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)（見(jian)圖4-16），形狀(zhuang)像“8”字(zi)(zi)，一端(duan)是(shi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)，另一端(duan)是(shi)節流環(huan)（墊(dian)環(huan)），但直徑與管道(dao)的管徑相同，并(bing)不(bu)起節流作(zuo)用。8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)，使用方(fang)便，需要(yao)隔離時(shi)，使用盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)端(duan)，需要(yao)正常操作(zuo)時(shi)，使用節流環(huan)（墊(dian)環(huan)）端(duan)，同時(shi)也可用于(yu)填補管路上盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)的安(an)裝間隙。另一個特(te)點(dian)就是(shi)標識明顯(xian)，易于(yu)辨(bian)認安(an)裝狀(zhuang)態(tai)。主要(yao)用于(yu)小于(yu)等于(yu)DN600的管道(dao)系(xi)統。插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)(ban)（見(jian)圖4-17）和(he)墊(dian)環(huan)（見(jian)圖4-18）互為盲(mang)(mang)通，和(he)8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)的作(zuo)用類似，主要(yao)用于(yu)大(da)于(yu)DN600的管道(dao)系(xi)統。8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)(ban)和(he)墊(dian)環(huan)的有(you)關標準，可參見(jian)HG/T 21547《管道(dao)用鋼制(zhi)插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)(ban)、墊(dian)環(huan)、8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)(ban)、墊(dian)環(huan)）、API 590Steel Line Blanks（8字(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)(ban)、墊(dian)環(huan)）。


圖 17.jpg


  有(you)配管(guan)設計人常咨詢筆者8字(zi)盲板(ban)(ban)與(yu)插(cha)板(ban)(ban)墊(dian)(dian)環(huan)(huan)的(de)口徑(jing)分界問(wen)題(ti)。不(bu)同的(de)設計單(dan)位分界口徑(jing)和(he)(he)壓力等級可能不(bu)相同，8字(zi)盲板(ban)(ban)和(he)(he)插(cha)板(ban)(ban)墊(dian)(dian)環(huan)(huan)在本質(zhi)上沒有(you)什么區別，區別就(jiu)是當管(guan)徑(jing)比較大、壓力等級高的(de)情(qing)況(kuang)下，8字(zi)盲板(ban)(ban)的(de)體(ti)積及重(zhong)量比較大，不(bu)方便(bian)拆卸，因此這時候通常使用(yong)(yong)(yong)插(cha)板(ban)(ban)墊(dian)(dian)環(huan)(huan)來代替。例如對于Class 150的(de)管(guan)道，DN300以下常用(yong)(yong)(yong)8字(zi)盲板(ban)(ban)，DN350以上常用(yong)(yong)(yong)插(cha)板(ban)(ban)墊(dian)(dian)環(huan)(huan)。具體(ti)見(jian)《工業管(guan)道配管(guan)設計與(yu)工程(cheng)應用(yong)(yong)(yong)》、《管(guan)道器材選用(yong)(yong)(yong)與(yu)工程(cheng)應用(yong)(yong)(yong)》的(de)詳細(xi)講述。


  某DN600插板墊環：材料選(xuan)用A516-70，厚度和等(deng)級選(xuan)用Class150。端部選(xuan)用RF（突面），標準選(xuan)用ASME B16.48。