首(shou)先在(zai)钢管(guan)上用开(kai)(kai)孔(kong)机开(kai)(kai)孔(kong)，然后将(jiang)机械(xie)三通卡入孔(kong)洞，孔(kong)四周由密封圈沿(yan)管(guan)壁密封。机械(xie)三通分(fen)丝(si)接和沟槽式两种(zhong)。机械(xie)三通连接时，应检查机械(xie)三通与(yu)孔(kong)洞的间(jian)隙，各(ge)部位应均匀，然后再紧固到位；机械(xie)三通开(kai)(kai)孔(kong)间(jian)距不应小于1m。

机(ji)械(xie)(xie)三(san)(san)(san)通(tong)连接(jie)方式(shi)广(guang)泛(fan)用于建筑内(nei)的消火栓(shuan)系统(tong)与喷(pen)淋系统(tong)。支(zhi)(zhi)管(guan)(guan)(guan)(guan)接(jie)头(tou)是指在(zai)(zai)直管(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)道(dao)中(zhong)部开孔后连接(jie)支(zhi)(zhi)管(guan)(guan)(guan)(guan)的鞍形拼合式(shi)连接(jie)件，分为机(ji)械(xie)(xie)三(san)(san)(san)通(tong)和(he)机(ji)械(xie)(xie)四通(tong)两种类型(xing)。在(zai)(zai)设计图纸上一(yi)般(ban)不会标(biao)注(zhu)出沟(gou)(gou)槽三(san)(san)(san)通(tong)和(he)机(ji)械(xie)(xie)三(san)(san)(san)通(tong)的。机(ji)械(xie)(xie)三(san)(san)(san)通(tong)或机(ji)械(xie)(xie)四通(tong)与支(zhi)(zhi)管(guan)(guan)(guan)(guan)的连接(jie)方式(shi)有沟(gou)(gou)槽式(shi)连接(jie)和(he)螺(luo)纹式(shi)连接(jie)两种，当支(zhi)(zhi)管(guan)(guan)(guan)(guan)道(dao)小于DN50，且主管(guan)(guan)(guan)(guan)道(dao)直径(jing)大于分支(zhi)(zhi)直径(jing)2倍时可用机(ji)械(xie)(xie)三(san)(san)(san)通(tong)（直接(jie)在(zai)(zai)主管(guan)(guan)(guan)(guan)道(dao)上开孔，喷(pen)淋支(zhi)(zhi)管(guan)(guan)(guan)(guan)与主管(guan)(guan)(guan)(guan)连接(jie)用得多），其它情况得用沟(gou)(gou)槽三(san)(san)(san)通(tong)。这里(li)的沟(gou)(gou)槽三(san)(san)(san)通(tong)就是正三(san)(san)(san)通(tong)（主支(zhi)(zhi)管(guan)(guan)(guan)(guan)中(zhong)心(xin)线成直角），因为不像UPVC管(guan)(guan)(guan)(guan)、铸(zhu)铁管(guan)(guan)(guan)(guan)除正三(san)(san)(san)角还有Y三(san)(san)(san)通(tong)（斜(xie)三(san)(san)(san)通(tong)）、TY三(san)(san)(san)通(tong)。

正(zheng)三(san)(san)(san)通(tong)(tong)与(yu)镀锌(xin)配(pei)件的(de)(de)(de)(de)三(san)(san)(san)通(tong)(tong)叫(jiao)法一(yi)样(yang)，只是(shi)镀锌(xin)三(san)(san)(san)通(tong)(tong)是(shi)丝扣连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)，而这里(li)正(zheng)三(san)(san)(san)通(tong)(tong)是(shi)沟(gou)槽式(shi)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)，每个(ge)(ge)管(guan)(guan)道(dao)(dao)的(de)(de)(de)(de)平口端环形沟(gou)槽由(you)专(zhuan)门的(de)(de)(de)(de)滚槽机(ji)加工成(cheng)型，与(yu)管(guan)(guan)道(dao)(dao)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)需要(yao)3副相应规格卡(ka)(ka)箍(gu)(gu)才能(neng)完成(cheng)一(yi)个(ge)(ge)接(jie)(jie)(jie)(jie)(jie)头，适(shi)合(he)主(zhu)(zhu)干管(guan)(guan)的(de)(de)(de)(de)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)。至于机(ji)械(xie)(xie)三(san)(san)(san)通(tong)(tong)主(zhu)(zhu)管(guan)(guan)上(shang)只需用(yong)开孔机(ji)开孔无需开槽，而支(zhi)管(guan)(guan)或开槽（沟(gou)槽式(shi)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)）或套丝（螺纹(wen)(wen)式(shi)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)），适(shi)合(he)主(zhu)(zhu)支(zhi)管(guan)(guan)间的(de)(de)(de)(de)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)（如喷淋系统的(de)(de)(de)(de)喷淋支(zhi)管(guan)(guan)）。另外还有一(yi)种(zhong)小机(ji)械(xie)(xie)三(san)(san)(san)通(tong)(tong)，只是(shi)把卡(ka)(ka)箍(gu)(gu)换成(cheng)了(le)U型卡(ka)(ka)，以(yi)我看这种(zhong)小机(ji)械(xie)(xie)三(san)(san)(san)通(tong)(tong)与(yu)支(zhi)管(guan)(guan)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)还是(shi)以(yi)螺纹(wen)(wen)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)为(wei)主(zhu)(zhu)，可能(neng)没有沟(gou)槽连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)形式(shi)。正(zheng)三(san)(san)(san)通(tong)(tong)一(yi)般指三(san)(san)(san)个(ge)(ge)接(jie)(jie)(jie)(jie)(jie)管(guan)(guan)直(zhi)(zhi)径(jing)(jing)(jing)(jing)相同(tong)而异径(jing)(jing)(jing)(jing)三(san)(san)(san)通(tong)(tong)则三(san)(san)(san)个(ge)(ge)接(jie)(jie)(jie)(jie)(jie)管(guan)(guan)直(zhi)(zhi)径(jing)(jing)(jing)(jing)不(bu)完全相同(tong)。正(zheng)三(san)(san)(san)通(tong)(tong)用(yong)于同(tong)一(yi)直(zhi)(zhi)径(jing)(jing)(jing)(jing)管(guan)(guan)道(dao)(dao)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)之用(yong)，异径(jing)(jing)(jing)(jing)三(san)(san)(san)通(tong)(tong)则用(yong)于不(bu)同(tong)直(zhi)(zhi)径(jing)(jing)(jing)(jing)管(guan)(guan)道(dao)(dao)的(de)(de)(de)(de)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)。机(ji)械(xie)(xie)三(san)(san)(san)通(tong)(tong)连(lian)(lian)(lian)(lian)(lian)(lian)接(jie)(jie)(jie)(jie)(jie)的(de)(de)(de)(de)支(zhi)管(guan)(guan)直(zhi)(zhi)径(jing)(jing)(jing)(jing)绝(jue)不(bu)可能(neng)等于主(zhu)(zhu)管(guan)(guan)直(zhi)(zhi)径(jing)(jing)(jing)(jing)。