中英文化工元件對照表

1、流體設(shè)備相關(guān)英漢對照表2008-11-14 13:551 管道組成件piping component1.1 管子 pipe管子 （ 按照配管標準規(guī)格制造的 ） pipe管子 （ 不按配管標準規(guī)格制造的其他用管） tube鋼管 steel pipe鑄鐵管cast iron pipe襯里管lined pipe復(fù)合管clad pipe碳鋼管carbon steel pipe合金鋼管 alloy steel pipe不銹鋼stainless steel pipe奧氏體不銹鋼管austenitic stainless steel pipe鐵合金鋼管ferritic alloy steel pipe軋制鋼

2、管wrought-steel pipe鍛鐵管 wrought-iron pipe無縫鋼管seamless （smls） steelpipe焊接鋼管welded steel pipe電阻焊鋼管electric-resistance welded steel pipe電熔（弧）焊鋼板卷管electric-fusion （arc）-welded steel-plate pipe螺旋焊接鋼管spiral welded steel pipe鍍鋅鋼管galvanized steel pipe熱軋無縫鋼管hot-rolling seamless pipe冷拔無縫鋼管cold-drawing seamless

3、 pipe水煤氣鋼管water-gas steel pipe塑料管plastic pipe玻璃管glass tube橡膠管rubber tube直管 run pipe; straight pipe1.2 管件 fitting彎頭 elbow異徑彎頭 reducing elbow帶支座彎頭base elbowk 半徑彎頭long radius elbow短半徑彎頭short radius elbow長半徑180 彎頭long radius return短半徑180 彎頭short radius return帶側(cè)向口的彎頭（右向或左向） side outlet elbow （right hand

4、or left hand） 雙支管彎頭（ 形） double branch elbow三通 tee異徑三通reducing tee等徑三通straight tee帶側(cè)向口的三通（右向或左向） side outlet tee （right hand or 1eft hand）異徑三通（分支口為異徑） reducing tee （reducing on outlet）異徑三通（一個直通口為異徑） reducing tee （reducing on one run）帶支座三通base tee異徑三通（一個直通口及分支口為異徑）reducing tee （reducing on one runoutl

5、et）異徑三通（兩個直通口為異徑，雙頭式）reducing tee （reducing on both runs, bull head）45 斜三通 45 lateral45 斜三通（支管為異徑） 45 lateral （reducing on branch）45 斜三通 （ 一個直通口為異徑） 45 lateral （reducing on one run）45 斜三通 （ 一個直通口及支管為異徑） 45 lateral （reducing on one runbranch）y 型三通（俗稱褲衩） true “ y”四通 cross等徑四通straight cross異徑四通reducing

6、 cross異徑四通（一個分支口為異徑） reducing cross （reducing on one outlet）異徑四通（一個直通口及分支口為異徑） reducing cross （reducing on one runoutlet）異徑四通（兩個分支口為異徑） reducing cross （reducing on both outlet）異徑四通（一個直通口及兩個分支口為異徑） reducing cross （reducing on one runboth outlet）異徑管 reducer同心異徑管concentric reducer偏心異徑管eccentric reducer

7、鍛制異徑管reducing swage螺紋支管臺threadolet焊接支管臺weldolet承插支管臺sockolet彎頭支管臺elbolet斜接支管臺latrolet鑲?cè)胧街Ч茏靤weepolet短管支管臺nipolet支管臺，插入式支管臺 boss管接頭coupling, full coupling半管接頭 half coupling異徑管接頭reducing coupling活接頭 union內(nèi)外螺紋縮接（俗稱補芯） bushing管帽 cap （c）堵頭 plug短節(jié) nipple異徑短節(jié) reducing nipple; swage nipple1.3 彎管 bend預(yù)制彎管 fa

8、bricated pipe bend跨越彎管(a 形) cross-over bend偏置彎管( 形) offset bend90 彎管 quarter bend環(huán)形彎管 cirele bend單側(cè)偏置90彎管(?形) single offset quarter bends 形彎管“s”bend單側(cè)偏置 u 形膨脹彎管( | ? 形) single offset“ u” bendu 形彎管“u”bend雙偏置 u 膨脹彎管 double offset expansion“ u” be nd斜接彎管mitre bend三節(jié)斜接彎管3-piece mitre bend折皺彎管corrugated

9、bend圓度 roundness1.4 法蘭 flange (flg )整體管法蘭integral pipe flange鋼管法蘭 steel pipe flange螺紋法蘭threaded flange滑套法蘭(包括平焊法蘭) slip-on flange (so); slip-on welding flange承插焊法蘭 socket welding flange松套法蘭lap joint flange (ljf)對焊法蘭welding neckflange (wnf)法蘭蓋 blind flange, blind孔板法蘭orifice flange異徑法蘭reducing flange盤

10、座式法蘭pad type flange松套帶頸法蘭loose hubbed flange焊接板式法蘭welding plate flange對焊環(huán)welding neck collar (與 stub end 相似)平焊環(huán)welding-on collar突緣短節(jié) stub end, lap翻邊端lapped pipe end松套板式法蘭loose plate flange壓力級 pressure rating, pressure rating class壓力 溫度等級 pressure-temperature rating法蘭密封面，法蘭面flange facing突面 raised fac

11、e (rf)凸面 male face (mf)凹面female face (fmf)榫面tongue face槽面 groove face環(huán)連接面ring joint face全平面；滿平面flat face; full face (ff)光滑突面smooth raised face (srf)法蘭面加工facing finish粗糙度roughness光滑的smooth齒形 serrated均方根root mean square (rms)算術(shù)平均粗糙高度arithmetical average roughness height (aarh)配對法蘭 companion-flange螺栓圓b

12、olt circle (b.c.)1.5 墊片 gasket (gskt)墊片的型式type of gasket平墊片flat gasket環(huán)形平墊片flat ring gasket平金屬墊片flat metal gasket夾棉織物的橡膠 elastomer with cotton fabric insertion夾石棉織物的橡膠 elastomer with asbestos fabric insertion夾石棉織物及金屬絲加強的橡膠 elastomer with asbestos fabric insertionwith wire reinforcement無石墨壓縮白石棉墊片non

13、graphited compressed white asbestos gasket天然白橡膠墊片natural white rubber gasket壓縮石棉墊片compressed asbestos class gasket浸聚四氟乙烯的石棉墊片ptfe impregnated asbestos gasket夾石棉的纏繞金屬墊片 spiral-wound metal gasket with asbestos filler內(nèi)環(huán) inner ring外環(huán)，外定位環(huán)outer ring波紋金屬墊片corrugated metal gasket波紋金屬包嵌石棉墊片 corrugated metal

14、 gasket with asbestos inserted雙夾套波紋金屬包石棉墊片 corrugated metal double jacketed asbestos filled gasket雙夾套墊片double jacketed gasket金屬包石棉平墊片 flat metal jacketed asbestos filled gasket整體金屬齒形墊片solid metal serrated gasket槽形金屬墊片grooved metal gasket環(huán)形連接金屬墊片ring joint metal gasket八角環(huán)形墊片octagonal ring gasket橢圓環(huán)形墊

15、片oval ring gasket透鏡式墊片lens gasket非金屬墊片non-metallic gasket1.6 閥門 valve1.6.1 閥門結(jié)構(gòu)、零件 閥軛 yoke外螺紋閥桿及閥軛outside screwyoke (os & y)閥桿 stem內(nèi)螺紋inside screw(is)閥軛套yoke sleeve閥桿環(huán)stem ring閥座 valve seat (body seat)閥座環(huán)、密封圈 seat ring整體(閥)座integral seat堆焊(閥)座deposited seat閥芯(包括密封圈、桿等內(nèi)件) trim閥盤disc閥盤密封圈 disc seat閥體b

16、ody閥蓋bonnet閥蓋襯套bonnet bush螺紋閥帽screw cap螺紋閥蓋screw bonnet螺栓連接的閥蓋bolted bonnet (bb)活接閥蓋(帽)union bonnet (cap)螺栓連接的閥帽bolted cap (bc)焊接閥蓋welded bonnet (wb)本體閥桿密封body stem seal石棉安全密封asbestos emenen seal倒密封 back seal壓力密封的閥蓋pressure-tight bonnet動力操縱器powered operator電動操縱器electric motor operator氣動操縱器pneumatic

17、operator液壓操縱器hydraulic operator快速操縱器quick-acting operator滑動閥桿 sliding stem正齒輪傳動spur gear operated傘齒輪傳動bevel gear operated扳手操作wrench operated鏈輪chain wheel手輪hand wheel手柄hand lever (handle)氣缸(或液壓缸)操縱的 cylinder operated鏈條操縱的 chain operated等徑孔道full bore; full port異徑孔道reducing bore, reduced port,venturi p

18、ort 短型 short pattern緊湊型(小型) compact type籠式環(huán) lantern ring壓蓋 gland閥桿填料stem packing閥蓋墊片bonnet gasket升桿式(明桿) rising stem (rs)非升桿式(暗桿) non-rising stem (nrs)指示器 / 限位器 indicator/stopper注油器 grease injector可更換的閥座環(huán)renewable seat ring1.6.2 常用閥(1 )閘閥 gate valve平行雙閘板double disc parallelseat開口楔形閘板split wedge撓性整體楔

19、形閘扳flexible solid wedge整體楔形閘板solid wedge塞型閘閥plug gate valve直通型閘閥through conduit gate valve(2) 截止閥globe valve球心型閥盤globe type disc塞型閥盤plug type disc可轉(zhuǎn)動的閥盤 swivel disc(3) 節(jié)流閃閥 throttle valve針閥 needle valve(4) 角閥angle valve(5) y 型閥( y 型閥體截止閥) y-valve (y-body globe valve)(6) 球閥ball valve三通球閥3-way ball va

20、lve裝有底軸的trunnion mounted耐火型 fire safe type浮動球型 floating ball type防脫出閥桿blowout proof stem(7) 蝶閥 butterfly valve對夾式(薄片型) wafer type凸耳式 lug type偏心閥板蝶閥 offset disc burerfly valve; eccentric butterfly valve斜閥盤蝶閥canted disc butterfly valve連桿式蝶閥link butterfly valve(8) 柱塞閥piston type valve(9) 旋塞閥 plug valve

21、三通旋塞閥three-way plug valve四通旋塞閥 four-way plug valve旋塞 cock襯套旋塞 sleeve cock(10) 隔膜閥 diaphragm valve橡膠襯里隔膜閥 rubber lined diaphragm valve直通式隔膜閥 straight way diaphragm valve堰式隔膜閥 weir diaphragm valve(11) 夾緊式膠管閥 pinch valve (用于泥漿、粉塵等)(12) 止回閥 check valve升降式止回閥lift check valve旋啟式止回閥swing check valve, flap

22、check valve落球式止回閥ball check valve彈簧球式止回閥 spring ball check valve雙板對夾式止回閥 dual plate wafer type check valve無撞擊聲止回閥non-slam cheek valve底閥 foot valve切斷式止回閥 stop check valve; non-return valve活塞式止回閥piston check valve斜翻盤止回閥tilting disc check valve蝶式止回閥butterfly check valve1.6.3 其它用途的閥安全泄氣閥safety valve (sv

23、)安全泄液閥relief valve (rv)安全泄壓閥safety relief valve杠桿重錘式leverweight type引導閥操縱的安全泄氣閥 pilot operated safety valve復(fù)式安全泄氣閥 twin type safety valve罐底排污閥 flush-bottom tank valve電磁閥 solenoid valve, solenoid operated valve電動閥electrically operated valve, electric-motor operated valve氣動閥pneumatic operated valve低溫用

24、閥 cryogenic service valve蒸汽疏水閥 steam trap機械式疏水閻mechanical trap浮桶式疏水閥open bucket trap, open top bucket trap浮球式疏水閥float trap倒吊桶式疏水閥inverted bucket trap自由浮球式疏水閥 loose float trap恒溫式疏水閥thermostatic trap金屬膨脹式蒸汽疏水閥metal expansion steam trap液體膨脹式蒸汽疏水閥liquid expansion steam trap雙金屬膨脹式蒸汽疏水閥 bimetallic expansi

25、on steam trap壓力平衡式恒溫疏水閥 balanced pressure thermostatic trap熱動力式疏水閥 thermodynamic trap脈沖式蒸汽疏水閥 impulse steam trap（疏水閥用）放氣閥（自動放氣閥） air vent valve （automatic air vent valve）平板式滑動閘閥 slab type sliding gate valve蓋閥 flat valve換向閥 diverting valve, reversing valve熱膨脹閥 thermo expansion valve自動關(guān)閉閥self-closing

26、gate valve自動排液閥self-draining valve管道盲板閥line-blind valve擠壓閥squeeze valve（用于泥漿及粉塵等）呼吸閥breather valve風門、擋板damper減壓閥pressure reducing valve, reducing valve控制閥control valve膜式控制閥diaphragm operated control valve執(zhí)行機構(gòu) actuator背壓調(diào)節(jié)閥back pressure regulating valve差壓調(diào)節(jié)閥differential pressure regulating valve壓力比例調(diào)

27、節(jié)閥 pressure ratio regulating valve1.6.4 未指明結(jié)構(gòu)（或閥型）的閥切斷閥blockvalve; shut-off valve; stop valve調(diào)節(jié)閥regulating valve快開閥quickopening valve快閉閥quickclosing valve隔斷閥isolating valve三通閥three way valve夾套闊jacketed valve非旋轉(zhuǎn)式閥 non-rotary valve排污閥blowdown valve集液排放閥 drip valve排液閥drain valve放空閥vent valve卸載閥unloadin

28、g valve排出閥discharge valve吸入閥suction valve多通路閥multiport valve取樣閥sampling valve手動閥hand-operated valve; manually operated valve鍛造閥forged valve鑄造閥cast valve（水）龍頭bibb; bib; faucet抽出液閥（小閥） bleed valve旁路閥by-pass valve軟管閥hose valve混合閥mixing valve破真空閥 vacuum breaker沖洗閥flush valve第一道閥；根部閥 primary valve根部閥root

29、 valve總管閥header valve事故切斷閥 emergency valve1.7 管道特殊件piping specialty1.7.1 管道特殊件（組件）粗濾器strainer過濾器filter臨時粗濾器（錐型） temporary strainer （cone type）y 型粗濾器y-type strainert 型粗濾器t-type strainer永久過濾器permanent filter絲網(wǎng)粗濾器gauze strainer洗眼器及淋浴器eye washershower視鏡 sight glass阻火器flame arrester噴嘴；噴頭spray nozzle取樣冷卻器

30、sample cooler消聲器silencer膨脹節(jié)expansion joint波紋膨脹節(jié)bellow expansionjoint單波 single bellow雙波 double bellow多波 multiple bellow壓力平衡式膨脹節(jié)pressure balanced expansion帶鉸鏈膨脹節(jié)hinged expansion joint軸向位移型膨脹節(jié)axial movement type expansion joint自均衡膨脹節(jié)（外加強環(huán)） self-equalizing expansion joint帶接桿膨脹節(jié)tied expansion joint萬向型膨脹節(jié)

31、universal type expansion joint球形補償器ball type expansion joint填函式補償器slip type （packed type） expansion joint單向滑動填料函補償器single actionpacked slip joint1.7.2 管道特殊元件 piping special element軟管接頭hose connection(hc)快速接頭quick coupling金屬軟管metal hose橡膠管rubber hose撓性管flexible tube鞍形補強板reinforcing saddles補強板reinforc

32、ementpad特殊法蘭special flange漏斗funnel排液環(huán) drip ring排液漏斗drain funnel插板 blank墊環(huán) spacer8 字盲板spectacle blind; figure 8 blind限流孔板restriction orifice爆破片 rupture disk法蘭蓋貼面protective disc費托立克接頭victaulic coupling9 .8 端部連接 end connection法蘭端flanged end坡口端beveled end (be)對焊端butt welded end平端 plain end (pe)承插焊端 sock

33、et welding end螺紋端threaded end (te)承口 bell end焊接端 welding end法蘭連接(接頭)flanged joint對焊連接(接頭)butt welded joint螺紋連接，管螺紋連接threaded joint, pipe threaded joint錐管螺紋密封焊連接seal-welded taper pipe threaded joint承插焊連接(接頭) socket welded joint承插連接(接頭)bellspigot joint環(huán)墊接頭ring joint (rj)萬向接頭universal joint軟釬焊連接(接頭)sol

34、dered joint搭接接頭，松套連接lapped joint外側(cè)厚度切斜角bevel for outside thickncss內(nèi)側(cè)厚度切斜角bevel for inside thickness內(nèi)外側(cè)厚度切斜角 bevel for combined thickness法蘭式的 flanged (flgd)對焊的butt welded (bw)螺紋的threaded (thd)承插焊的 socket welded (sw)小端為平的small endplain (sep)大端為平的large endplain (lep)兩端平both ends plain (bep)小端帶螺紋smallen

35、dthread (set)大端帶螺紋largeendthread (let)兩端帶螺紋bothend thread (bet)一端帶螺紋oneend thread (oet)支管連接branchconnection焊接支管branchpipe welded directly to the run pipe2 管道用緊固件及螺紋2.1 緊固件螺栓 bolt六角頭螺栓 hexagonal head bolt方頭螺栓square head bolt螺柱，雙頭螺栓 stud bolt環(huán)頭螺檢eye bolt沉頭螺栓countersunk (head)screw地腳螺栓anchor bolt; foun

36、dation bolt松緊螺旋扣(花籃螺絲) turnbuckleu 形螺栓u-boltt 形螺栓t-bolt圓頭螺釘 round head bolt機螺栓，機螺釘 maehine bolt頂開螺栓，頂起螺栓 jack screw自攻螺釘self tapping screw膨脹螺栓expansion bolt粗制的coarse精制的finished, fine螺母 nut六角螺母 hexagonal nut方螺母square nut蝶形螺母wing nut扁螺母 flat nut鎖緊螺母lock nut墊圈washer平墊圈 plain washer球面墊圈spherical washer彈簧

37、墊圈spring washer方墊圈square washer斜墊圈slant washer銷軸 pinned shan銷 pin開口銷cotter pin定位銷dowel pin帶孔銷pin with hole圓錐銷taper pin鉚釘rivet鍵 key2.2 螺紋左螺紋lefthand thread右螺紋right hand thread管螺紋pipe thread錐管螺紋 taper pipe thread直管螺紋straight pipe thread梯形螺紋trapezoid thread螺距 pitch of thread粗牙螺紋coarse thread細牙螺紋fine th

38、read特細牙螺紋extra fine thread通長螺紋full thread惠氏螺紋whitworth thread公制螺紋metric ibread美國標準錐管螺紋american standard taper pipe thread (npt)螺孔 tap3 材料、型鋼及填料3.1 金屬材料3.1.1 黑色金屬 ferrous metal碳素鋼carbon steel (cs)低碳鋼low-carbon steel中碳鋼medium-carbon steel高碳鋼high-carbon steel普通碳素鋼general carbon steel優(yōu)質(zhì)碳素鋼high-quality c

39、arbon steel普通低合金結(jié)構(gòu)鋼 general structure low-alloy steel合金結(jié)構(gòu)鋼structural alloy steel合金鋼alloy steel低合金鋼low alloy steel中合金鋼medium alloy steel高合金鋼high alloy steel耐熱鋼heat resisting steel高強度鋼high strength steel復(fù)合鋼clad steel工具鋼tool steel彈簧鋼spring steel鉬鋼 molybdenum steel鎳鋼 nickel steel鉻鋼 chromium steel鉻鉬鋼chro

40、me-molybdenum steel鉻鎳鋼chromium-nickel steel,chrome-nickelsteel不銹鋼stainless steel (s.s.)奧氏體不銹鋼austenitic stainless steel馬氏體不銹鋼martensitic stainless steel司特來合金(鎢鉻鈷臺金) stellite耐蝕耐熱鎳基合金 hastelloy鉻鎳鐵合金 inconel耐熱鉻鎳鐵合金 incoloy20 合金 20 alloy平爐鋼(馬丁鋼) martin steel鎮(zhèn)靜鋼 killed steel半鎮(zhèn)靜鋼 semi-killed steel沸騰鋼rimme

41、d steel; rimming steel; open-steel鍛鋼 forged steel鑄鋼caststeel鑄鐵castiron (c.i.)灰鑄鐵grey cast iron可鍛鑄鐵malleableiron(mi)球墨鑄鐵nodular castiron;nodular graphite iron生鐵 pig iron熟鐵，鍛鐵wrought iron鑄件 casting高硅鑄鐵 high silicon cast iron3.1.2 鍍層及制造方法滲鉻鋼，鍍鉻鋼 chromized steel鍍鉻的chromium-plated, chrome-plated鍍層 platin

42、g鍛造，型鋼 swage鍛造的，鍛造forging軋制 rolling熱軋 hot rolling冷軋 cold rolling擠壓extruding冷加工cold working熱加工hot working拔制drawing3.1.3 有色金屬 non-ferrous metal鋁 aluminum銅，紫銅 copper黃銅 brass青銅 bronze鋁青銅aluminum bronze磷青銅phosphor bronze鋁鎂合金 aluminum magnesium錳青銅manganese bronze蒙乃爾（注：鎳及銅合金） monel鎳銅臺金nickel copper alloy非鐵

43、合金nonferrous alloy鈦 titanium鉛 lead硬鉛 hard lead3.1.4 材料性能極限強度ultimate strength抗拉強度tensile strength屈服極限yield limit屈服點yield point延伸率percentage elongation抗壓強度compressive strength抗彎強度bending strength彈性極限elastic limit沖擊值impact value疲勞極限fatigue limit蠕變極限creep limit持久極限endurance limit布氏硬度brinell hardness洛氏硬

44、度rockwell hardness維氏硬度vickers diamond hardness, diamond penetrator hardness蠕變斷裂強度creep rupture strength斷面收縮率reduction of area韌性 toughess脆性 brittleness延性ductility冷脆cold shortness冷流cold flow3.2 非金屬材料non-metallic material塑料plastic丙烯腈 丁二烯 苯乙烯 acrylonitrile-butadiene-styrene (abs)聚乙烯polyethylene (pe)聚氯乙烯

45、 polyvinyl chloride (pvc)苯乙烯橡膠 styrene-rubber (sr)聚丁烯polybutylene (pb)聚丙烯polypropylene (pp)聚苯乙烯 polystyrene (ps)氯化聚醚chlorinated polyether (cpe)聚酰胺polyamide (pa)聚碳酸酯polycarbonate (pc)聚甲基丙烯酸甲酯polymethyl methacrylate (pmma)醋酸丁酸纖維素cellulose acetate butyrate (cab)氯化聚氯乙烯chlorinated polyvinyl chloride (cpv

46、c)聚偏二氟乙烯polyvinylidene fluoride (pvdf)縮醛塑料 acetal plastic尼龍塑料 nylon plastic聚烯烴polyolefin (po)石墨酚醛塑料graphite phenolic plastics聚四氟乙烯polytetrafluoroethylene (ptfe)纖維增強熱塑性塑料fiber reinforced thermoplastics熱塑性塑料thermoplastic熱固性塑料thermosetting plastics膠粘劑 adhesive溶劑膠接劑solvent cement樹脂 resin環(huán)氧樹脂epoxy, epoxy

47、 resin聚酯樹脂polyester resin聚酯纖維polyester fibers氟塑料 fluoroplastics聚氨基甲酸酯polyurethane丙烯酸樹脂 acrylic resin脲醛樹脂urea resin呋哺樹脂furan resin乙烯丙烯二烴單體 ethylene propylene diene monomer (epdm)合成橡膠synthetic rubber橡膠rubber丁腈橡膠nitrile butadiene rubber氯丁橡膠neoprene天然橡膠natural rubber乙丙橡膠ethylene propylene rubber （epr）玻璃

48、glass硼硅玻璃borosilicate glass耐火磚 fire brick陶瓷 ceramic搪瓷porcelain enamel木材 wood3.3 型材型鋼 shaped steel, section steel, swage角鋼 angle steel槽鋼 channel工字鋼i-beam寬緣工字鋼或h 鋼 wide flanged beamt 型鋼t-bar方鋼 square bar扁鋼 flat bar角鋼hexagonal steel bar圓鋼round steel; rod鋼帶 strap steel鋼板 plate網(wǎng)紋鋼板 checkered plate腹板（指型鋼的

49、立板） web翼緣（指型鋼的緣） wing3.4 填料及填料函填料 packing石棉繩 asbestos rope, asbestos cord o 形環(huán)o-ring自密封self-sealing四氟帶teflon tap帶鉻鎳合金絲的石棉繩asbestos rope with inconel wire, inconel wire asbestos浸聚四氟乙烯的石棉填料teflon impregnated asbestos packing金屬填料 metallic stuffing填料箱，填料函 packing box, stuffing box填料函壓蓋stuffing box gland4 管道等級及材料統(tǒng)計4.1 管道材料規(guī)定 piping material specification管道等級 piping class; piping classification管道等級號class designation公稱直徑nominal diameter (dn);nominal (pipe) size公稱壓力nominal pressure (pn)壓力級，等級，類別 class (cl)低壓low pressure (l.p