盲(mang)板(ban)（Blind）、8字(zi)盲(mang)板(ban)（Spectacle Blind； Figure 8 Blind）、插板(ban)（Paddle Blank）以及(ji)墊環（Paddle Spacer），制(zhi)造方法一般分(fen)三(san)種：鍛(duan)打(da)、鑄鍛(duan)、中板(ban)割(ge)制(zhi)。其(qi)中鍛(duan)打(da)產品價格最高，中板(ban)次之，鑄鍛(duan)最低。而質量是鍛(duan)打(da)和中板(ban)的(de)好(hao)，鑄鍛(duan)的(de)要稍差些。盲(mang)板(ban)或(huo)“8”字(zi)盲(mang)板(ban)與(yu)閥(fa)門相比，其(qi)關斷作用更可靠而且更經濟。

  盲板、“8”字盲板、插板以(yi)及墊環都應有(you)兩個和匹配法(fa)蘭(lan)同樣(yang)的密封面。常用(yong)的密封面包含平面、凹(ao)凸面、榫槽(cao)面和環連面。

  盲板(ban)（見圖4-15）用(yong)于(yu)(yu)(yu)起隔離(li)(li)、切斷作用(yong)的(de)(de)，和封(feng)頭、管帽所(suo)起的(de)(de)作用(yong)是一(yi)(yi)樣(yang)的(de)(de)。由于(yu)(yu)(yu)其(qi)密(mi)封(feng)性能好，對于(yu)(yu)(yu)需(xu)要完全隔離(li)(li)的(de)(de)系統，一(yi)(yi)般都(dou)作為(wei)可(ke)(ke)靠的(de)(de)隔離(li)(li)手段。盲板(ban)就是一(yi)(yi)個帶柄的(de)(de)實(shi)心的(de)(de)圓，用(yong)于(yu)(yu)(yu)通常狀(zhuang)況下處于(yu)(yu)(yu)隔離(li)(li)狀(zhuang)態的(de)(de)系統。盲板(ban)的(de)(de)有關標準，可(ke)(ke)參(can)見HG/T 20592～20635《鋼制管法蘭、墊(dian)片、緊固(gu)件(jian)(jian)》和ASME B16.5《管法蘭和法蘭管件(jian)(jian)》。

  8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)（見(jian)圖(tu)4-16），形狀像“8”字(zi)，一(yi)端(duan)(duan)是(shi)盲(mang)(mang)板(ban)(ban)(ban)(ban)，另(ling)一(yi)端(duan)(duan)是(shi)節流環(huan)(huan)(huan)（墊(dian)(dian)環(huan)(huan)(huan)），但直徑與管(guan)道的(de)(de)(de)管(guan)徑相同，并不起節流作(zuo)用(yong)(yong)(yong)。8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)，使用(yong)(yong)(yong)方便，需(xu)要(yao)(yao)隔離時，使用(yong)(yong)(yong)盲(mang)(mang)板(ban)(ban)(ban)(ban)端(duan)(duan)，需(xu)要(yao)(yao)正常操作(zuo)時，使用(yong)(yong)(yong)節流環(huan)(huan)(huan)（墊(dian)(dian)環(huan)(huan)(huan)）端(duan)(duan)，同時也可(ke)用(yong)(yong)(yong)于(yu)(yu)填補(bu)管(guan)路(lu)上盲(mang)(mang)板(ban)(ban)(ban)(ban)的(de)(de)(de)安(an)裝(zhuang)間(jian)隙(xi)。另(ling)一(yi)個特點就是(shi)標識明顯，易于(yu)(yu)辨認安(an)裝(zhuang)狀態(tai)。主(zhu)要(yao)(yao)用(yong)(yong)(yong)于(yu)(yu)小于(yu)(yu)等于(yu)(yu)DN600的(de)(de)(de)管(guan)道系(xi)統(tong)(tong)。插(cha)(cha)板(ban)(ban)(ban)(ban)（見(jian)圖(tu)4-17）和(he)墊(dian)(dian)環(huan)(huan)(huan)（見(jian)圖(tu)4-18）互為盲(mang)(mang)通，和(he)8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)的(de)(de)(de)作(zuo)用(yong)(yong)(yong)類似，主(zhu)要(yao)(yao)用(yong)(yong)(yong)于(yu)(yu)大(da)于(yu)(yu)DN600的(de)(de)(de)管(guan)道系(xi)統(tong)(tong)。8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)和(he)墊(dian)(dian)環(huan)(huan)(huan)的(de)(de)(de)有(you)關標準，可(ke)參見(jian)HG/T 21547《管(guan)道用(yong)(yong)(yong)鋼制插(cha)(cha)板(ban)(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)、8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)）、API 590Steel Line Blanks（8字(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)(ban)、墊(dian)(dian)環(huan)(huan)(huan)）。

  有(you)(you)配管設計人常(chang)(chang)咨詢筆者8字盲(mang)(mang)板(ban)(ban)與插板(ban)(ban)墊(dian)環(huan)的(de)口徑分界問題。不(bu)同的(de)設計單(dan)位(wei)分界口徑和壓力等級(ji)(ji)可能不(bu)相同，8字盲(mang)(mang)板(ban)(ban)和插板(ban)(ban)墊(dian)環(huan)在(zai)本質(zhi)上(shang)沒有(you)(you)什(shen)么區(qu)別，區(qu)別就是當管徑比較大、壓力等級(ji)(ji)高的(de)情(qing)況(kuang)下(xia)，8字盲(mang)(mang)板(ban)(ban)的(de)體(ti)積及重量比較大，不(bu)方便拆卸，因此這(zhe)時候通(tong)常(chang)(chang)使用插板(ban)(ban)墊(dian)環(huan)來代(dai)替。例如對(dui)于Class 150的(de)管道，DN300以(yi)下(xia)常(chang)(chang)用8字盲(mang)(mang)板(ban)(ban)，DN350以(yi)上(shang)常(chang)(chang)用插板(ban)(ban)墊(dian)環(huan)。具體(ti)見《工(gong)業管道配管設計與工(gong)程(cheng)應(ying)用》、《管道器材選(xuan)用與工(gong)程(cheng)應(ying)用》的(de)詳細(xi)講述。

  某DN600插板(ban)墊(dian)環：材料選(xuan)用(yong)(yong)A516-70，厚度和等(deng)級選(xuan)用(yong)(yong)Class150。端(duan)部選(xuan)用(yong)(yong)RF（突(tu)面），標準選(xuan)用(yong)(yong)ASME B16.48。