①. 伴(ban)(ban)(ban)(ban)中管(guan)(guan)(guan)(guan)(guan)線的(de)(de)(de)口徑(jing):一般伴(ban)(ban)(ban)(ban)中管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)徑(jing)不小于DN15。有的(de)(de)(de)工(gong)程(cheng)(cheng)熱水、蒸汽(qi)伴(ban)(ban)(ban)(ban)中管(guan)(guan)(guan)(guan)(guan)線全(quan)(quan)部采用DN15的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)子。有的(de)(de)(de)工(gong)程(cheng)(cheng)蒸汽(qi)伴(ban)(ban)(ban)(ban)熱伴(ban)(ban)(ban)(ban)中管(guan)(guan)(guan)(guan)(guan)子全(quan)(quan)部采用DN15的(de)(de)(de),熱水伴(ban)(ban)(ban)(ban)熱伴(ban)(ban)(ban)(ban)中管(guan)(guan)(guan)(guan)(guan)子全(quan)(quan)部采用DN20的(de)(de)(de)。SH/T 3040《石油(you)化工(gong)管(guan)(guan)(guan)(guan)(guan)道(dao)伴(ban)(ban)(ban)(ban)管(guan)(guan)(guan)(guan)(guan)及夾套管(guan)(guan)(guan)(guan)(guan)設計(ji)規(gui)范》內規(gui)定(ding)伴(ban)(ban)(ban)(ban)管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)徑(jing)宜為10、12、DN15、DN20或DN25。有的(de)(de)(de)工(gong)程(cheng)(cheng)伴(ban)(ban)(ban)(ban)管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)徑(jing)有DN40的(de)(de)(de)。
伴(ban)(ban)管(guan)(guan)(guan)(guan)的(de)(de)管(guan)(guan)(guan)(guan)徑比較(jiao)(jiao)小時容易堵塞,伴(ban)(ban)管(guan)(guan)(guan)(guan)的(de)(de)管(guan)(guan)(guan)(guan)徑較(jiao)(jiao)大時不宜熱煨彎纏繞和施工(gong),需根(gen)(gen)據具體工(gong)程項目實際(ji)情況選用(yong)。浙江至德(de)鋼業有限(xian)公司技術人員在某施工(gong)現場,看到伴(ban)(ban)管(guan)(guan)(guan)(guan)口徑采用(yong)較(jiao)(jiao)大,根(gen)(gen)本無(wu)法靈活(huo)地伴(ban)(ban)主管(guan)(guan)(guan)(guan)彎曲(qu),造(zao)成隔熱層較(jiao)(jiao)大,后來統一更換成了較(jiao)(jiao)小口徑的(de)(de)伴(ban)(ban)管(guan)(guan)(guan)(guan)。
②. 伴(ban)中管線的有效伴(ban)熱長度(du)
a. 熱水伴(ban)管(guan)沿被伴(ban)熱管(guan)的有效伴(ban)熱長度(包括垂直管(guan)道),可(ke)按表13.1的要求確定。

b. 蒸汽伴(ban)管(guan)(guan)最大(da)(da)允許有效伴(ban)熱(re)(re)(re)長度(du)(du)。伴(ban)管(guan)(guan)沿被伴(ban)熱(re)(re)(re)管(guan)(guan)的(de)(de)有效伴(ban)熱(re)(re)(re)長度(du)(du)(包括垂直管(guan)(guan)道)可(ke)按表13.2的(de)(de)要求確定(ding)。當伴(ban)熱(re)(re)(re)蒸汽的(de)(de)凝結水不回收(shou)時,表13.2中(zhong)(zhong)最大(da)(da)允許有效伴(ban)熱(re)(re)(re)長度(du)(du)可(ke)增(zeng)大(da)(da)20%,采用導熱(re)(re)(re)膠泥后伴(ban)管(guan)(guan)的(de)(de)最大(da)(da)允許有效伴(ban)熱(re)(re)(re)長度(du)(du)宜減(jian)小20%。當伴(ban)管(guan)(guan)在最大(da)(da)允許伴(ban)熱(re)(re)(re)長度(du)(du)內出現U形彎(wan)時,伴(ban)管(guan)(guan)累計上升(sheng)高度(du)(du)不宜大(da)(da)于表13.3中(zhong)(zhong)規定(ding)的(de)(de)數值。

c. 當(dang)導(dao)熱(re)油供油壓力(li)不(bu)低于0.15MPa(表(biao)壓),溫度不(bu)低于200℃時導(dao)熱(re)油伴管的最(zui)大(da)有效伴熱(re)長(chang)度不(bu)應(ying)超過60m。
③. 熱(re)水(shui)伴(ban)(ban)(ban)熱(re)伴(ban)(ban)(ban)管的(de)根數(shu)見(jian)(jian)表(biao)13.4。蒸汽(qi)伴(ban)(ban)(ban)熱(re)伴(ban)(ban)(ban)管的(de)根數(shu)見(jian)(jian)表(biao)13.5。
④. 對蒸(zheng)汽伴(ban)熱(re)和(he)熱(re)水伴(ban)熱(re)的(de)伴(ban)熱(re)供汽/水和(he)凝液/回水的(de)伴(ban)前伴(ban)后管總(zong)長度應限制在30m內。
⑤. 對熱水(shui)伴(ban)(ban)熱,所有來自同一站(zhan)的(de)伴(ban)(ban)管(guan)(guan)應有相似(si)的(de)壓降(jiang),以實現均勻流動。為了達到此(ci)目的(de),最(zui)短(duan)伴(ban)(ban)管(guan)(guan)的(de)當量(liang)長度不宜小于最(zui)長伴(ban)(ban)管(guan)(guan)當量(liang)長度的(de)70%,否則需采取(qu)在伴(ban)(ban)熱供水(shui)/供汽(qi)管(guan)(guan)切斷閥下游安(an)裝(zhuang)限流孔板或截止閥等措(cuo)施。
⑥. 對熱(re)(re)水伴熱(re)(re)時(shi),伴管的(de)袋形(xing)高度沒有限制,宜(yi)從被伴熱(re)(re)的(de)管道(dao)的(de)最低點(dian)開始至最高點(dian),然后返回至熱(re)(re)水系(xi)統。
⑦. 當水質較差或結(jie)垢嚴重時,一(yi)般宜在(zai)熱水伴管的供水和回(hui)水靠近切斷閥的地方設清洗口(kou)。
⑧. 每根蒸汽(qi)(qi)/熱水(shui)伴管應(ying)有其(qi)獨立的(de)供汽(qi)(qi)/供水(shui)閥和(he)冷凝(ning)液疏水(shui)閥,不宜與(yu)其(qi)他(ta)伴管合(he)并疏水(shui)。通過(guo)疏水(shui)閥后(hou)的(de)不回收(shou)凝(ning)結水(shui)宜集中排放(fang)。
⑨. 附(fu)屬于管道上的(de)在線儀表,如壓(ya)力(li)計(ji)等通(tong)常應與(yu)被伴(ban)熱的(de)管道和(he)設備一起伴(ban)熱。
⑩. 安全(quan)閥(fa)的伴(ban)熱應盡可能靠近(jin)閥(fa)座,以(yi)避免出故障。
?. 為防止被(bei)伴(ban)設(she)施過熱,非金(jin)屬閥(fa)座的閥(fa)、堿管、胺(an)管伴(ban)管應(ying)根據伴(ban)管管徑(jing)按間距1~1.5m安裝(zhuang)隔(ge)離墊(dian),隔(ge)離墊(dian)的大小一般為50mm×25mm×10mm,見圖13.11。

?. 所有伴管(包括伴熱供汽、供水和回水的伴管)彎管不能被壓扁,防止影響伴熱效果。
?. 應用鋼(gang)帶(dai)或鋼(gang)絲在間(jian)隔1.0~1.5m處固定(ding)伴(ban)(ban)管(guan)(根據伴(ban)(ban)管(guan)管(guan)徑大小(xiao));但(dan)這(zhe)種間(jian)隔在彎頭(tou)處應適(shi)當縮小(xiao)距離(li),因為(wei)在這(zhe)些地方(fang)伴(ban)(ban)管(guan)與管(guan)子(zi)的接(jie)觸不緊(jin)。
?. 伴管(guan)的熱(re)補償方法(fa)
a、利用伴管越過被伴熱設備或管道上的法蘭、閥門等形成的彎管作為熱補償。
b.管(guan)道伴(ban)(ban)熱時(shi),可以將伴(ban)(ban)管(guan)的中點固定在(zai)被伴(ban)(ban)熱管(guan)道上。伴(ban)(ban)管(guan)不得直(zhi)接焊接在(zai)被伴(ban)(ban)管(guan)上作(zuo)固定點。
c. 補償(chang)器可(ke)采用U形、Ω形或(huo)螺旋纏繞(rao)型。也(ye)可(ke)以將(jiang)伴(ban)管作(zuo)(zuo)為統一考慮,設(she)置(zhi)一個膨(peng)脹(zhang)環或(huo)設(she)置(zhi)II形補償(chang)彎(wan)(wan)管,使其自然補償(chang),如圖13.12所示。對蒸(zheng)汽伴(ban)熱(re)間隔約(yue)24m,對熱(re)水伴(ban)熱(re)間隔約(yue)30m,應設(she)膨(peng)脹(zhang)彎(wan)(wan),閥門和(he)法蘭處的回彎(wan)(wan)應作(zuo)(zuo)為膨(peng)脹(zhang)彎(wan)(wan)對待。

d. 伴管(guan)加熱應合理(li)設置固定支架及導向(xiang)支架。
e. 伴(ban)(ban)管(guan)(guan)隨被伴(ban)(ban)管(guan)(guan)轉彎(wan)作自然補償時,伴(ban)(ban)管(guan)(guan)固定點的設置應(ying)使被伴(ban)(ban)管(guan)(guan)彎(wan)頭處(chu)的保溫(wen)結構(gou)不受損壞。
f. 伴管(guan)的高(gao)低(di)點(dian)可不(bu)設高(gao)點(dian)排氣與低(di)點(dian)排液(ye)。
?. 在被(bei)伴設施需維修處,伴管(guan)應采用(yong)法蘭(lan)或活接(jie)(jie)頭連(lian)接(jie)(jie),如控制閥、安全閥、轉子流量計等,伴熱管(guan)道的分支(zhi)采用(yong)三通連(lian)接(jie)(jie)。
?. 冷(leng)凝水應采取必要(yao)的排放措施,不宜直接排入明溝或(huo)(huo)漏斗或(huo)(huo)地面上。
?. 熱水伴管特(te)殊要求(qiu)。
a. 伴后熱水應回(hui)收。
b. 伴(ban)管(guan)繞過閥(fa)門(men)或法(fa)蘭時(shi),伴(ban)管(guan)最大(da)的有效長度要相應縮短,每一(yi)處可按3m直管(guan)考慮,伴(ban)管(guan)每拐一(yi)個90°彎(wan)按1m考慮。
?. 伴熱管的安(an)裝
a. 伴熱管的連接
應(ying)不妨礙伴熱管(guan)與輸(shu)送管(guan)的(de)緊靠。一般(ban)采用(yong)對接焊接及冷彎(wan)(熱煨彎(wan))的(de)效果較(jiao)好。對經常拆卸輸(shu)送管(guan)的(de)法蘭處,伴熱管(guan)用(yong)法蘭(或活接頭)連接。紫銅管(guan)的(de)接頭往往留在保溫層外面。
b. 伴熱管的固(gu)定帶
蒸汽伴熱管用鋼帶固定在被加熱的輸送管道上。固定帶寬約15mm,厚約1mm;或用Φ1.6mm鍍鋅鐵絲。固定帶間距如表13.6。沿輸送管的彎頭敷設伴熱管時,每個彎頭所用的固定帶不應少于3根。


