盲(mang)板(ban)(ban)（Blind）、8字盲(mang)板(ban)(ban)（Spectacle Blind； Figure 8 Blind）、插(cha)板(ban)(ban)（Paddle Blank）以及(ji)墊環（Paddle Spacer），制(zhi)(zhi)造方法一般分三(san)種：鍛(duan)打、鑄鍛(duan)、中(zhong)板(ban)(ban)割制(zhi)(zhi)。其中(zhong)鍛(duan)打產品價格最高(gao)，中(zhong)板(ban)(ban)次(ci)之，鑄鍛(duan)最低。而質(zhi)量是鍛(duan)打和中(zhong)板(ban)(ban)的(de)好，鑄鍛(duan)的(de)要稍(shao)差些。盲(mang)板(ban)(ban)或“8”字盲(mang)板(ban)(ban)與閥(fa)門相(xiang)比，其關(guan)斷(duan)作用(yong)更可靠(kao)而且(qie)更經(jing)濟。

  盲板、“8”字盲板、插板以及墊環都應(ying)有(you)兩個和(he)匹配(pei)法蘭(lan)同樣的密封(feng)面(mian)(mian)。常(chang)用的密封(feng)面(mian)(mian)包含平面(mian)(mian)、凹凸面(mian)(mian)、榫槽面(mian)(mian)和(he)環連面(mian)(mian)。

  盲(mang)板（見圖4-15）用(yong)于(yu)起(qi)隔(ge)(ge)離(li)(li)、切斷作用(yong)的(de)(de)，和封(feng)頭、管(guan)帽所起(qi)的(de)(de)作用(yong)是(shi)一(yi)樣的(de)(de)。由于(yu)其密封(feng)性能好，對(dui)于(yu)需要(yao)完全隔(ge)(ge)離(li)(li)的(de)(de)系統，一(yi)般都作為可(ke)靠的(de)(de)隔(ge)(ge)離(li)(li)手段。盲(mang)板就是(shi)一(yi)個(ge)帶(dai)柄的(de)(de)實(shi)心的(de)(de)圓(yuan)，用(yong)于(yu)通(tong)常狀(zhuang)況下處于(yu)隔(ge)(ge)離(li)(li)狀(zhuang)態(tai)的(de)(de)系統。盲(mang)板的(de)(de)有關標準，可(ke)參見HG/T 20592～20635《鋼制管(guan)法(fa)(fa)蘭、墊(dian)片、緊固件》和ASME B16.5《管(guan)法(fa)(fa)蘭和法(fa)(fa)蘭管(guan)件》。

  8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)（見圖4-16），形狀像“8”字(zi)，一端(duan)是(shi)盲(mang)(mang)(mang)板(ban)(ban)(ban)，另(ling)一端(duan)是(shi)節(jie)流(liu)(liu)環(huan)(huan)(huan)(huan)（墊(dian)(dian)環(huan)(huan)(huan)(huan)），但直(zhi)徑(jing)(jing)與管道(dao)的(de)(de)管徑(jing)(jing)相同，并不起節(jie)流(liu)(liu)作用(yong)(yong)(yong)。8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)，使(shi)用(yong)(yong)(yong)方便，需要(yao)(yao)隔(ge)離時，使(shi)用(yong)(yong)(yong)盲(mang)(mang)(mang)板(ban)(ban)(ban)端(duan)，需要(yao)(yao)正(zheng)常操作時，使(shi)用(yong)(yong)(yong)節(jie)流(liu)(liu)環(huan)(huan)(huan)(huan)（墊(dian)(dian)環(huan)(huan)(huan)(huan)）端(duan)，同時也(ye)可(ke)用(yong)(yong)(yong)于(yu)(yu)填(tian)補管路(lu)上盲(mang)(mang)(mang)板(ban)(ban)(ban)的(de)(de)安裝間隙。另(ling)一個特(te)點就是(shi)標(biao)識(shi)明顯，易于(yu)(yu)辨認安裝狀態。主要(yao)(yao)用(yong)(yong)(yong)于(yu)(yu)小(xiao)于(yu)(yu)等于(yu)(yu)DN600的(de)(de)管道(dao)系(xi)統。插板(ban)(ban)(ban)（見圖4-17）和(he)墊(dian)(dian)環(huan)(huan)(huan)(huan)（見圖4-18）互為盲(mang)(mang)(mang)通，和(he)8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)的(de)(de)作用(yong)(yong)(yong)類似，主要(yao)(yao)用(yong)(yong)(yong)于(yu)(yu)大于(yu)(yu)DN600的(de)(de)管道(dao)系(xi)統。8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)、插板(ban)(ban)(ban)和(he)墊(dian)(dian)環(huan)(huan)(huan)(huan)的(de)(de)有關標(biao)準，可(ke)參見HG/T 21547《管道(dao)用(yong)(yong)(yong)鋼(gang)制(zhi)插板(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)(huan)、8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)、插板(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)(huan)）、API 590Steel Line Blanks（8字(zi)盲(mang)(mang)(mang)板(ban)(ban)(ban)、插板(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)(huan)）。

  有配管(guan)設計人常(chang)咨詢筆者8字(zi)盲(mang)板(ban)與(yu)插板(ban)墊(dian)環(huan)的(de)口(kou)徑(jing)分(fen)界問題。不同的(de)設計單位分(fen)界口(kou)徑(jing)和壓力等級可能不相同，8字(zi)盲(mang)板(ban)和插板(ban)墊(dian)環(huan)在本質(zhi)上(shang)沒有什么區別，區別就是當管(guan)徑(jing)比(bi)較(jiao)大、壓力等級高的(de)情況下(xia)，8字(zi)盲(mang)板(ban)的(de)體(ti)(ti)積及重量(liang)比(bi)較(jiao)大，不方便拆卸，因此這(zhe)時(shi)候通(tong)常(chang)使用(yong)(yong)插板(ban)墊(dian)環(huan)來代替。例如對于Class 150的(de)管(guan)道，DN300以(yi)下(xia)常(chang)用(yong)(yong)8字(zi)盲(mang)板(ban)，DN350以(yi)上(shang)常(chang)用(yong)(yong)插板(ban)墊(dian)環(huan)。具(ju)體(ti)(ti)見《工(gong)業管(guan)道配管(guan)設計與(yu)工(gong)程應用(yong)(yong)》、《管(guan)道器材(cai)選(xuan)用(yong)(yong)與(yu)工(gong)程應用(yong)(yong)》的(de)詳細講(jiang)述(shu)。

  某DN600插板墊環：材(cai)料選用(yong)A516-70，厚(hou)度和等級(ji)選用(yong)Class150。端部選用(yong)RF（突面(mian)），標(biao)準選用(yong)ASME B16.48。