有(you)的設計人(ren)員認(ren)為,只有(you)可燃(ran)介質(zhi)管(guan)道才需要靜(jing)電接地(di),非可燃(ran)介質(zhi)(如儀(yi)表風、工廠風、氮(dan)氣(qi)等(deng))管(guan)道不需要靜(jing)電接地(di),這是不正(zheng)確(que)的。
起火(huo)、爆(bao)(bao)炸(zha)(zha)(zha)發生需(xu)要三(san)個(ge)條件:存(cun)(cun)(cun)在(zai)(zai)可燃(ran)介(jie)質,可燃(ran)介(jie)質和(he)氧氣(qi)(qi)接(jie)觸,存(cun)(cun)(cun)在(zai)(zai)足夠引(yin)(yin)燃(ran)可燃(ran)介(jie)質和(he)氧氣(qi)(qi)混合物的火(huo)花(hua)。由靜(jing)(jing)電(dian)引(yin)(yin)發的火(huo)災(zai)或(huo)(huo)爆(bao)(bao)炸(zha)(zha)(zha)事故,一(yi)定是(shi)(shi)由于靜(jing)(jing)電(dian)放電(dian)產(chan)(chan)生電(dian)火(huo)花(hua)引(yin)(yin)燃(ran)或(huo)(huo)引(yin)(yin)爆(bao)(bao)泄漏到管道(dao)或(huo)(huo)設備外部的可燃(ran)氣(qi)(qi)體或(huo)(huo)可燃(ran)粉塵(chen)與氧氣(qi)(qi)的混合物而(er)(er)產(chan)(chan)生的。只要存(cun)(cun)(cun)在(zai)(zai)可燃(ran)氣(qi)(qi)體或(huo)(huo)可燃(ran)粉塵(chen)集聚(ju)的區域,都存(cun)(cun)(cun)在(zai)(zai)因靜(jing)(jing)電(dian)放電(dian)或(huo)(huo)引(yin)(yin)發火(huo)災(zai)或(huo)(huo)爆(bao)(bao)炸(zha)(zha)(zha)的風險(xian)。判(pan)斷管道(dao)是(shi)(shi)否(fou)(fou)需(xu)要靜(jing)(jing)電(dian)接(jie)地(di)的依據(ju),不是(shi)(shi)其內的介(jie)質是(shi)(shi)否(fou)(fou)可燃(ran),而(er)(er)是(shi)(shi)其是(shi)(shi)否(fou)(fou)位于火(huo)災(zai)和(he)爆(bao)(bao)炸(zha)(zha)(zha)危(wei)(wei)(wei)險(xian)區域內。SH 3097和(he)HG 20675中(zhong)有(you)明確的規定,對爆(bao)(bao)炸(zha)(zha)(zha)和(he)火(huo)災(zai)危(wei)(wei)(wei)險(xian)環境內可能產(chan)(chan)坐靜(jing)(jing)電(dian)危(wei)(wei)(wei)害的物體,應采取工(gong)業靜(jing)(jing)電(dian)接(jie)地(di)措施。
有人認(ren)為(wei),水(shui)是(shi)導(dao)電(dian)(dian)(dian)的(de)(de),所(suo)以水(shui)管道(dao)、蒸(zheng)汽(qi)(qi)管道(dao)不需(xu)要接(jie)地。事實(shi)上,蒸(zheng)汽(qi)(qi)不是(shi)電(dian)(dian)(dian)的(de)(de)良(liang)導(dao)體(ti),水(shui)本(ben)身(shen)也不導(dao)電(dian)(dian)(dian),導(dao)電(dian)(dian)(dian)的(de)(de)是(shi)存(cun)在導(dao)電(dian)(dian)(dian)離子(zi)的(de)(de)水(shui)。而(er)很(hen)多(duo)水(shui),如鍋(guo)爐(lu)水(shui)、除氧水(shui)、蒸(zheng)汽(qi)(qi)冷(leng)凝液等(deng)都除去了大部分導(dao)電(dian)(dian)(dian)離子(zi),其導(dao)電(dian)(dian)(dian)性能并不好(hao)。即使是(shi)循環(huan)水(shui),為(wei)了減少(shao)換熱(re)設備(bei)結垢,也是(shi)經(jing)過軟化處理,脫除了大部分的(de)(de)鈣(gai)鎂離子(zi)。除非經(jing)過實(shi)驗證明工藝裝置所(suo)用的(de)(de)水(shui)在管道(dao)內有良(liang)好(hao)的(de)(de)導(dao)電(dian)(dian)(dian)性,不能認(ren)為(wei)水(shui)是(shi)導(dao)電(dian)(dian)(dian)的(de)(de)而(er)取消爆炸和(he)火災危(wei)險區內蒸(zheng)汽(qi)(qi)和(he)水(shui)管道(dao)的(de)(de)靜(jing)電(dian)(dian)(dian)接(jie)地要求。

