盲板(ban)（Blind）、8字(zi)盲板(ban)（Spectacle Blind； Figure 8 Blind）、插板(ban)（Paddle Blank）以及墊環（Paddle Spacer），制造方法一(yi)般分三種：鍛(duan)打、鑄鍛(duan)、中(zhong)(zhong)(zhong)板(ban)割制。其中(zhong)(zhong)(zhong)鍛(duan)打產品價格最高，中(zhong)(zhong)(zhong)板(ban)次(ci)之，鑄鍛(duan)最低(di)。而(er)質量是鍛(duan)打和中(zhong)(zhong)(zhong)板(ban)的(de)好，鑄鍛(duan)的(de)要稍(shao)差些(xie)。盲板(ban)或(huo)“8”字(zi)盲板(ban)與閥門相比，其關(guan)斷作用更可靠而(er)且更經濟。


  盲板(ban)、“8”字(zi)盲板(ban)、插板(ban)以及墊環(huan)都應(ying)有兩(liang)個(ge)和匹配(pei)法(fa)蘭同(tong)樣的(de)密封面。常(chang)用的(de)密封面包含平(ping)面、凹凸面、榫槽面和環(huan)連面。


  盲板(ban)（見圖4-15）用(yong)(yong)于(yu)(yu)起隔(ge)離(li)(li)(li)、切斷作(zuo)(zuo)(zuo)用(yong)(yong)的(de)(de)，和封頭、管帽所起的(de)(de)作(zuo)(zuo)(zuo)用(yong)(yong)是一樣的(de)(de)。由于(yu)(yu)其(qi)密(mi)封性能好(hao)，對于(yu)(yu)需要完(wan)全隔(ge)離(li)(li)(li)的(de)(de)系統，一般(ban)都作(zuo)(zuo)(zuo)為可靠的(de)(de)隔(ge)離(li)(li)(li)手段。盲板(ban)就是一個帶柄的(de)(de)實(shi)心的(de)(de)圓，用(yong)(yong)于(yu)(yu)通常狀況下處于(yu)(yu)隔(ge)離(li)(li)(li)狀態的(de)(de)系統。盲板(ban)的(de)(de)有關標準，可參見HG/T 20592～20635《鋼制管法蘭(lan)、墊片、緊固件(jian)》和ASME B16.5《管法蘭(lan)和法蘭(lan)管件(jian)》。


圖 15.jpg


  8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)（見圖4-16），形狀像“8”字(zi)(zi)，一端(duan)是(shi)(shi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)，另一端(duan)是(shi)(shi)節流(liu)(liu)環(huan)(huan)（墊環(huan)(huan)），但(dan)直徑(jing)與管(guan)道(dao)的(de)(de)管(guan)徑(jing)相同，并不起節流(liu)(liu)作用(yong)(yong)(yong)。8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)，使用(yong)(yong)(yong)方便，需要隔離時(shi)，使用(yong)(yong)(yong)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)端(duan)，需要正(zheng)常操作時(shi)，使用(yong)(yong)(yong)節流(liu)(liu)環(huan)(huan)（墊環(huan)(huan)）端(duan)，同時(shi)也可(ke)用(yong)(yong)(yong)于(yu)填補管(guan)路上盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)的(de)(de)安裝(zhuang)間隙。另一個特點就(jiu)是(shi)(shi)標(biao)識明顯，易(yi)于(yu)辨認安裝(zhuang)狀態。主(zhu)要用(yong)(yong)(yong)于(yu)小(xiao)于(yu)等于(yu)DN600的(de)(de)管(guan)道(dao)系(xi)統(tong)。插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)（見圖4-17）和墊環(huan)(huan)（見圖4-18）互為盲(mang)(mang)(mang)通，和8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)的(de)(de)作用(yong)(yong)(yong)類似，主(zhu)要用(yong)(yong)(yong)于(yu)大(da)于(yu)DN600的(de)(de)管(guan)道(dao)系(xi)統(tong)。8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)和墊環(huan)(huan)的(de)(de)有(you)關(guan)標(biao)準，可(ke)參見HG/T 21547《管(guan)道(dao)用(yong)(yong)(yong)鋼制插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)(huan)、8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)(huan)）、API 590Steel Line Blanks（8字(zi)(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)(huan)）。


圖 17.jpg


  有配(pei)管(guan)設計(ji)人(ren)常咨(zi)詢筆(bi)者(zhe)8字盲(mang)(mang)板(ban)(ban)與插(cha)板(ban)(ban)墊(dian)環(huan)的(de)(de)口徑(jing)分(fen)界問題。不(bu)同(tong)的(de)(de)設計(ji)單位分(fen)界口徑(jing)和壓(ya)力(li)等級(ji)可能不(bu)相同(tong)，8字盲(mang)(mang)板(ban)(ban)和插(cha)板(ban)(ban)墊(dian)環(huan)在本(ben)質(zhi)上(shang)沒有什么(me)區別，區別就是當管(guan)徑(jing)比較(jiao)大、壓(ya)力(li)等級(ji)高(gao)的(de)(de)情況(kuang)下(xia)，8字盲(mang)(mang)板(ban)(ban)的(de)(de)體積及重量比較(jiao)大，不(bu)方便拆卸，因(yin)此(ci)這(zhe)時候通常使用插(cha)板(ban)(ban)墊(dian)環(huan)來代替。例(li)如對于Class 150的(de)(de)管(guan)道，DN300以下(xia)常用8字盲(mang)(mang)板(ban)(ban)，DN350以上(shang)常用插(cha)板(ban)(ban)墊(dian)環(huan)。具體見《工(gong)(gong)業(ye)管(guan)道配(pei)管(guan)設計(ji)與工(gong)(gong)程應用》、《管(guan)道器材選(xuan)用與工(gong)(gong)程應用》的(de)(de)詳細講述。


  某DN600插板墊環(huan)：材料選用A516-70，厚度和(he)等級選用Class150。端部選用RF（突面），標準選用ASME B16.48。