盲板(ban)(ban)（Blind）、8字盲板(ban)(ban)（Spectacle Blind； Figure 8 Blind）、插(cha)板(ban)(ban)（Paddle Blank）以(yi)及(ji)墊(dian)環（Paddle Spacer），制造(zao)方法一般分三種：鍛(duan)打(da)、鑄(zhu)鍛(duan)、中(zhong)板(ban)(ban)割(ge)制。其中(zhong)鍛(duan)打(da)產品價格最(zui)高，中(zhong)板(ban)(ban)次之，鑄(zhu)鍛(duan)最(zui)低。而質量(liang)是鍛(duan)打(da)和中(zhong)板(ban)(ban)的(de)(de)好，鑄(zhu)鍛(duan)的(de)(de)要稍差些。盲板(ban)(ban)或(huo)“8”字盲板(ban)(ban)與閥門相比，其關(guan)斷(duan)作用更可靠而且更經(jing)濟。


  盲板(ban)、“8”字盲板(ban)、插板(ban)以及墊環都(dou)應有兩個和匹配法蘭同樣(yang)的密(mi)封面。常用的密(mi)封面包含平面、凹凸面、榫槽面和環連面。


  盲板(ban)（見圖4-15）用(yong)(yong)于(yu)起(qi)(qi)隔離(li)、切(qie)斷(duan)作用(yong)(yong)的(de)，和封頭、管(guan)帽(mao)所起(qi)(qi)的(de)作用(yong)(yong)是一(yi)樣的(de)。由(you)于(yu)其(qi)密封性能好，對(dui)于(yu)需要完全隔離(li)的(de)系統(tong)，一(yi)般都作為可(ke)靠的(de)隔離(li)手段。盲板(ban)就(jiu)是一(yi)個(ge)帶柄的(de)實(shi)心(xin)的(de)圓，用(yong)(yong)于(yu)通(tong)常狀(zhuang)況(kuang)下(xia)處于(yu)隔離(li)狀(zhuang)態的(de)系統(tong)。盲板(ban)的(de)有關標準，可(ke)參見HG/T 20592～20635《鋼制管(guan)法(fa)蘭、墊片、緊固件》和ASME B16.5《管(guan)法(fa)蘭和法(fa)蘭管(guan)件》。


圖 15.jpg


  8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)（見(jian)圖4-16），形狀像“8”字(zi)(zi)(zi)，一端(duan)是盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)，另一端(duan)是節流(liu)環(huan)（墊環(huan)），但直(zhi)徑與(yu)管(guan)道的(de)(de)(de)(de)管(guan)徑相同，并(bing)不起節流(liu)作用(yong)。8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)，使(shi)用(yong)方便，需要隔離時，使(shi)用(yong)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)端(duan)，需要正常操作時，使(shi)用(yong)節流(liu)環(huan)（墊環(huan)）端(duan)，同時也可用(yong)于填補管(guan)路(lu)上盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)的(de)(de)(de)(de)安(an)裝間(jian)隙。另一個特(te)點就是標識明顯，易于辨認安(an)裝狀態。主(zhu)要用(yong)于小于等于DN600的(de)(de)(de)(de)管(guan)道系統(tong)。插(cha)板(ban)(ban)(ban)(ban)(ban)（見(jian)圖4-17）和(he)墊環(huan)（見(jian)圖4-18）互為(wei)盲(mang)(mang)通，和(he)8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)的(de)(de)(de)(de)作用(yong)類似，主(zhu)要用(yong)于大于DN600的(de)(de)(de)(de)管(guan)道系統(tong)。8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)板(ban)(ban)(ban)(ban)(ban)和(he)墊環(huan)的(de)(de)(de)(de)有關標準，可參見(jian)HG/T 21547《管(guan)道用(yong)鋼制插(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)、8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)》、ASME B16.48 Steel Line Blanks（8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)）、API 590Steel Line Blanks（8字(zi)(zi)(zi)盲(mang)(mang)板(ban)(ban)(ban)(ban)(ban)、插(cha)板(ban)(ban)(ban)(ban)(ban)、墊環(huan)）。


圖 17.jpg


  有配管(guan)(guan)設(she)計人常(chang)(chang)咨詢筆者8字(zi)盲(mang)板(ban)(ban)(ban)與(yu)插(cha)板(ban)(ban)(ban)墊環(huan)的(de)(de)口(kou)(kou)徑分界問(wen)題。不(bu)同的(de)(de)設(she)計單位分界口(kou)(kou)徑和壓(ya)力(li)等級可能不(bu)相同，8字(zi)盲(mang)板(ban)(ban)(ban)和插(cha)板(ban)(ban)(ban)墊環(huan)在本質上(shang)沒(mei)有什么區別，區別就是當管(guan)(guan)徑比(bi)較(jiao)大、壓(ya)力(li)等級高的(de)(de)情(qing)況下(xia)，8字(zi)盲(mang)板(ban)(ban)(ban)的(de)(de)體(ti)積及(ji)重量比(bi)較(jiao)大，不(bu)方便拆卸(xie)，因(yin)此這時候通常(chang)(chang)使用(yong)插(cha)板(ban)(ban)(ban)墊環(huan)來代替。例如對于Class 150的(de)(de)管(guan)(guan)道，DN300以下(xia)常(chang)(chang)用(yong)8字(zi)盲(mang)板(ban)(ban)(ban)，DN350以上(shang)常(chang)(chang)用(yong)插(cha)板(ban)(ban)(ban)墊環(huan)。具體(ti)見《工(gong)(gong)業管(guan)(guan)道配管(guan)(guan)設(she)計與(yu)工(gong)(gong)程應(ying)用(yong)》、《管(guan)(guan)道器材選用(yong)與(yu)工(gong)(gong)程應(ying)用(yong)》的(de)(de)詳(xiang)細講(jiang)述。


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