長輸管道（GA）指產地、儲存庫、使用(yong)(yong)單位間用(yong)(yong)于輸送商品介(jie)質(zhi)的壓力管道；公用(yong)(yong)管道（GB）指城市或(huo)鄉鎮(zhen)范圍內的用(yong)(yong)于公用(yong)(yong)事業(ye)或(huo)民用(yong)(yong)的燃(ran)氣管道和熱力管道。

  根(gen)據GB／T 34275《壓(ya)力管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)規范(fan) 長(chang)輸管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)》規定，GA類長(chang)輸管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)范(fan)圍：①. 設備上的(de)壓(ya)力管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)不在壓(ya)力管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)監(jian)管(guan)(guan)(guan)(guan)(guan)范(fan)圍內；②. 油(you)(you)氣(qi)(qi)田站場內油(you)(you)氣(qi)(qi)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)按(an)GC類管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)設計、施(shi)工(gong)和監(jian)管(guan)(guan)(guan)(guan)(guan)：③. 長(chang)輸管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)站場內油(you)(you)氣(qi)(qi)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)可(ke)按(an)GA或GC類管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)設計、施(shi)工(gong)，按(an)GC類管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)監(jian)管(guan)(guan)(guan)(guan)(guan)；④長(chang)輸管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)末(mo)站至工(gong)廠或城市燃(ran)氣(qi)(qi)門站的(de)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)按(an)GA類管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)設計、施(shi)工(gong)和監(jian)管(guan)(guan)(guan)(guan)(guan)；⑤廠際(ji)油(you)(you)氣(qi)(qi)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)可(ke)按(an)GA或GC類管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)設計、施(shi)工(gong)。見圖8-1所示。

  根(gen)據GB／T 38942《壓(ya)力管(guan)道(dao)規范公用管(guan)道(dao)》規定的GB類公用管(guan)道(dao)范圍(wei)如下。

一、包括

  ①. 城鎮(zhen)燃氣(qi)管(guan)道(dao)GB1：由門站(zhan)、儲(chu)配站(zhan)、各類氣(qi)源(yuan)廠站(zhan)等(deng)燃氣(qi)廠站(zhan)至用戶之間(jian)或(huo)廠站(zhan)之間(jian)公用性質的燃氣(qi)管(guan)道(dao)及(ji)附(fu)屬(shu)設(she)施(shi)，附(fu)屬(shu)設(she)施(shi)包括線路閥室、調壓站(zhan)（含調壓箱）、凝水缸等(deng)，見圖8-2所示。

  分輸站至門站之間的燃(ran)氣管道(dao)應(ying)執行GA類管道(dao)規范。當敷設在城市建成區時(shi)，可按GB1標(biao)準(zhun)執行。

  ②. 城(cheng)鎮(zhen)熱力管(guan)道(dao)(dao)：由熱源出口分界點至熱用(yong)戶（民(min)用(yong)或工(gong)業）進口分界點之間，敷設(she)在(zai)城(cheng)鎮(zhen)范圍內的蒸汽管(guan)道(dao)(dao)和熱水管(guan)道(dao)(dao)及(ji)其附屬設(she)施，見圖8-3所示。其中蒸汽介質設(she)計(ji)壓(ya)力小(xiao)于(yu)或等(deng)于(yu)2.5MPa，設(she)計(ji)溫度(du)小(xiao)于(yu)或等(deng)于(yu)350℃；熱水介質設(she)計(ji)壓(ya)力小(xiao)于(yu)或等(deng)于(yu)2.5MPa，設(she)計(ji)溫度(du)小(xiao)于(yu)或等(deng)于(yu)200℃。

二、不包括

  ①. 燃氣系統中(zhong)廠站內（調壓(ya)站除(chu)外）的燃氣管道(dao)和(he)熱(re)力系統中(zhong)廠站內（熱(re)力站和(he)熱(re)分配(pei)站除(chu)外）的熱(re)力管道(dao)。

  ②. 工業用戶內部燃氣和熱力管(guan)道（以廠界劃分）。

  ③. 商業(ye)和(he)(he)居民(min)用戶(hu)內部燃氣管道（以用戶(hu)引入管閥(fa)門為界）和(he)(he)熱(re)力管道（以熱(re)力人口為界）。

  ④. 燃氣(qi)和熱力設備內部管道。