盲(mang)板(ban)(ban)(ban)（Blind）、8字盲(mang)板(ban)(ban)(ban)（Spectacle Blind； Figure 8 Blind）、插板(ban)(ban)(ban)（Paddle Blank）以及墊(dian)環（Paddle Spacer），制造方法(fa)一(yi)般(ban)分三種：鍛(duan)打(da)、鑄(zhu)鍛(duan)、中(zhong)板(ban)(ban)(ban)割制。其中(zhong)鍛(duan)打(da)產品價格最高(gao)，中(zhong)板(ban)(ban)(ban)次之，鑄(zhu)鍛(duan)最低。而(er)質量是鍛(duan)打(da)和(he)中(zhong)板(ban)(ban)(ban)的好，鑄(zhu)鍛(duan)的要稍差(cha)些。盲(mang)板(ban)(ban)(ban)或“8”字盲(mang)板(ban)(ban)(ban)與閥門相比，其關(guan)斷作用更(geng)可靠而(er)且更(geng)經濟。

  盲板、“8”字盲板、插板以及墊環都應有兩個和匹配法蘭同(tong)樣的密封(feng)面(mian)。常用的密封(feng)面(mian)包含平面(mian)、凹凸面(mian)、榫(sun)槽面(mian)和環連面(mian)。

  盲(mang)板（見圖4-15）用于(yu)(yu)(yu)起隔離(li)、切(qie)斷作(zuo)用的(de)，和封頭、管帽所(suo)起的(de)作(zuo)用是一(yi)樣的(de)。由(you)于(yu)(yu)(yu)其密封性能好，對于(yu)(yu)(yu)需要完全隔離(li)的(de)系統(tong)，一(yi)般都作(zuo)為可靠的(de)隔離(li)手段。盲(mang)板就是一(yi)個帶柄的(de)實心的(de)圓，用于(yu)(yu)(yu)通常狀況下(xia)處(chu)于(yu)(yu)(yu)隔離(li)狀態(tai)的(de)系統(tong)。盲(mang)板的(de)有關標(biao)準，可參見HG/T 20592～20635《鋼制管法(fa)蘭(lan)、墊片、緊固件》和ASME B16.5《管法(fa)蘭(lan)和法(fa)蘭(lan)管件》。

  8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)（見圖4-16），形狀像(xiang)“8”字(zi)，一(yi)端是盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)，另一(yi)端是節(jie)(jie)流(liu)環(huan)(huan)(huan)（墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)），但直徑與管(guan)(guan)道的(de)管(guan)(guan)徑相同(tong)，并不起節(jie)(jie)流(liu)作用(yong)(yong)(yong)。8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)，使(shi)用(yong)(yong)(yong)方便，需要隔離時(shi)，使(shi)用(yong)(yong)(yong)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)端，需要正常操作時(shi)，使(shi)用(yong)(yong)(yong)節(jie)(jie)流(liu)環(huan)(huan)(huan)（墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)）端，同(tong)時(shi)也(ye)可(ke)用(yong)(yong)(yong)于(yu)填補管(guan)(guan)路(lu)上(shang)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)的(de)安裝(zhuang)間(jian)隙。另一(yi)個特點就是標(biao)識明顯，易于(yu)辨(bian)認安裝(zhuang)狀態(tai)。主要用(yong)(yong)(yong)于(yu)小于(yu)等(deng)于(yu)DN600的(de)管(guan)(guan)道系統(tong)。插(cha)(cha)板(ban)(ban)(ban)（見圖4-17）和(he)(he)墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)（見圖4-18）互為盲(mang)(mang)(mang)(mang)通，和(he)(he)8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)的(de)作用(yong)(yong)(yong)類似，主要用(yong)(yong)(yong)于(yu)大于(yu)DN600的(de)管(guan)(guan)道系統(tong)。8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)和(he)(he)墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)的(de)有關標(biao)準(zhun)，可(ke)參見HG/T 21547《管(guan)(guan)道用(yong)(yong)(yong)鋼制插(cha)(cha)板(ban)(ban)(ban)、墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)、8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)、墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)）、API 590Steel Line Blanks（8字(zi)盲(mang)(mang)(mang)(mang)板(ban)(ban)(ban)、插(cha)(cha)板(ban)(ban)(ban)、墊(dian)(dian)(dian)(dian)環(huan)(huan)(huan)）。

  有(you)(you)配(pei)管設(she)計(ji)(ji)人常咨詢筆者8字(zi)盲(mang)板(ban)(ban)(ban)與(yu)插(cha)板(ban)(ban)(ban)墊(dian)環的(de)(de)口徑(jing)分界問題(ti)。不同的(de)(de)設(she)計(ji)(ji)單(dan)位(wei)分界口徑(jing)和壓(ya)力(li)等級可能(neng)不相同，8字(zi)盲(mang)板(ban)(ban)(ban)和插(cha)板(ban)(ban)(ban)墊(dian)環在(zai)本質上沒有(you)(you)什么(me)區別(bie)，區別(bie)就是(shi)當(dang)管徑(jing)比(bi)較(jiao)大(da)、壓(ya)力(li)等級高的(de)(de)情況下(xia)，8字(zi)盲(mang)板(ban)(ban)(ban)的(de)(de)體積及重量比(bi)較(jiao)大(da)，不方便拆(chai)卸，因此這時候通常使用(yong)(yong)插(cha)板(ban)(ban)(ban)墊(dian)環來(lai)代替(ti)。例如對于Class 150的(de)(de)管道，DN300以下(xia)常用(yong)(yong)8字(zi)盲(mang)板(ban)(ban)(ban)，DN350以上常用(yong)(yong)插(cha)板(ban)(ban)(ban)墊(dian)環。具體見《工(gong)業管道配(pei)管設(she)計(ji)(ji)與(yu)工(gong)程應用(yong)(yong)》、《管道器材選用(yong)(yong)與(yu)工(gong)程應用(yong)(yong)》的(de)(de)詳細講述。

  某DN600插(cha)板(ban)墊(dian)環(huan)：材料(liao)選用(yong)A516-70，厚(hou)度和等(deng)級選用(yong)Class150。端(duan)部選用(yong)RF（突面），標準選用(yong)ASME B16.48。