Cov txheej txheem no muab cov lus pom zoo rau kev tsim qauv kev nyab xeeb ntawm cov kav dej rau hydrogen tis.
Hydrogen yog cov kua dej uas tsis muaj zog heev nrog lub siab nyiam heev.Nws yog ib qho txaus ntshai heev thiab ua rau tuag taus ua ke ntawm kev nyiam, cov kua dej tsis haum uas nyuaj rau tswj.Cov no yog cov qauv uas yuav tsum xav txog thaum xaiv cov khoom siv, gaskets thiab seals, nrog rau cov qauv tsim ntawm cov tshuab zoo li no.Cov ncauj lus no hais txog kev faib cov roj H2 yog qhov tseem ceeb ntawm qhov kev sib tham no, tsis yog kev tsim cov H2, kua H2, lossis kua H2 (saib sab xis).
Nov yog ob peb lub ntsiab lus tseem ceeb los pab koj nkag siab txog kev sib xyaw ntawm hydrogen thiab H2-air.Hydrogen hlawv nyob rau hauv ob txoj kev: deflagration thiab tawg.
deflagration.Deflagration yog hom combustion uas muaj nplaim taws taug kev los ntawm kev sib tov ntawm subsonic speeds.Qhov no tshwm sim, piv txwv li, thaum huab cua dawb ntawm hydrogen-cua sib tov yog ignited los ntawm qhov chaw me me.Nyob rau hauv cov ntaub ntawv no, cov nplaim yuav txav ntawm ib tug ceev ntawm kaum mus rau ob peb puas taw ib ob.Kev nthuav dav sai ntawm cov pa kub ua rau lub zog tsis muaj zog uas nws lub zog yog proportional rau qhov loj ntawm huab.Qee qhov xwm txheej, lub zog ntawm kev poob siab tuaj yeem ua rau muaj kev puas tsuaj rau lub tsev thiab lwm yam khoom hauv nws txoj kev thiab ua rau raug mob.
tawg.Thaum nws tawg, nplaim taws thiab kev poob siab tsis tau taug kev los ntawm kev sib tov ntawm supersonic ceev.Qhov sib piv siab nyob rau hauv lub nthwv dej detonation yog ntau ntau dua li hauv lub detonation.Vim muaj zog ntau, qhov tawg yog qhov txaus ntshai rau tib neeg, cov tsev thiab cov khoom nyob ze.Ib txwm deflagration ua rau tawg thaum ignited nyob rau hauv ib qho chaw kaw.Nyob rau hauv xws li ib tug nqaim cheeb tsam, ignition yuav tshwm sim los ntawm qhov tsawg kawg nkaus lub zog.Tab sis rau lub detonation ntawm hydrogen-cua sib tov nyob rau hauv ib tug unlimited qhov chaw, yuav tsum tau ib tug haib ignition qhov chaw.
Qhov sib piv siab thoob plaws lub detonation nthwv dej hauv hydrogen-cua sib tov yog hais txog 20. Ntawm atmospheric siab, qhov ratio ntawm 20 yog 300 psi.Thaum lub zog nthwv dej sib tsoo nrog cov khoom nyob ruaj ruaj, qhov sib piv siab nce mus rau 40-60.Qhov no yog vim qhov kev xav ntawm lub zog nthwv dej los ntawm qhov chaw ruaj khov.
Ntxim qab heev.Vim nws tsis tshua muaj viscosity thiab tsis tshua muaj molecular hnyav, H2 roj muaj ib tug siab nyiam mus los thiab txawm permeate los yog nkag mus rau ntau yam ntaub ntawv.
Hydrogen yog 8 lub sij hawm sib zog dua li cov nkev ntuj, 14 lub sij hawm sib zog tshaj huab cua, 22 lub sij hawm sib zog tshaj propane thiab 57 lub sij hawm sib zog tshaj roj av vapor.Qhov no txhais tau hais tias thaum ntsia sab nraum zoov, H2 roj yuav sai sai thiab ploj mus, txo cov tsos mob ntawm txawm tias xau.Tab sis nws tuaj yeem yog rab ntaj ob sab.Kev tawg tuaj yeem tshwm sim yog tias vuam yuav tsum tau ua rau ntawm qhov chaw sab nraum zoov saum toj lossis nqes qis ntawm H2 xau yam tsis muaj kev tshawb nrhiav pom ua ntej vuam.Nyob rau hauv ib qho chaw nyob ib puag ncig, H2 roj tuaj yeem nce thiab sib sau los ntawm lub qab nthab, ib qho xwm txheej uas tso cai rau nws tsim kom muaj ntau qhov loj ua ntej yuav muaj feem cuam tshuam nrog cov khoom siv hluav taws xob nyob ze hauv av.
Teeb meem hluav taws.Self-ignition yog ib tug tshwm sim nyob rau hauv uas ib tug sib tov ntawm gases los yog vapors ignites spontaneously yam tsis muaj lwm qhov chaw ntawm ignition.Nws tseem hu ua "spontaneous combustion" lossis "spontaneous combustion".Self-ignition nyob ntawm qhov kub thiab txias, tsis siab.
autoignition kub yog qhov tsawg kawg nkaus kub ntawm cov roj yuav spontaneously ignite ua ntej ignition nyob rau hauv tsis muaj ib tug sab nraud qhov chaw ntawm ignition thaum sib cuag nrog huab cua los yog ib tug oxidizing neeg sawv cev.Qhov kub ntawm autoignition ntawm ib cov hmoov yog qhov kub ntawm qhov uas nws spontaneously ignites thaum tsis muaj oxidizing tus neeg sawv cev.Tus kheej-ignition kub ntawm gaseous H2 nyob rau hauv huab cua yog 585 ° C.
Lub zog hluav taws xob yog lub zog xav tau los pib kev nthuav tawm ntawm cov nplaim taws los ntawm kev sib tov sib xyaw.Qhov tsawg kawg nkaus ignition zog yog qhov tsawg kawg nkaus lub zog yuav tsum tau ignite ib qho combustible sib tov ntawm ib tug tshwj xeeb kub thiab siab.Yam tsawg kawg nkaus hluav taws xob hluav taws xob rau gaseous H2 hauv 1 atm ntawm huab cua = 1.9 × 10–8 BTU (0.02 mJ).
Kev txwv tawg yog qhov siab tshaj plaws thiab qhov tsawg kawg nkaus ntawm cov vapors, pos huab lossis plua plav hauv huab cua lossis oxygen thaum muaj kev tawg.Qhov loj thiab geometry ntawm ib puag ncig, nrog rau cov concentration ntawm cov roj, tswj cov kev txwv."Explosion limit" yog qee zaum siv los ua ib lo lus rau "explosion limit".
Cov kev txwv tawg rau H2 cov khoom sib xyaw hauv huab cua yog 18.3 vol.% (qis txwv) thiab 59 vol.% (sab sauv txwv).
Thaum tsim cov kav dej (Daim duab 1), thawj kauj ruam yog los txiav txim siab cov khoom siv hauv tsev uas xav tau rau txhua hom kua dej.Thiab txhua cov kua dej yuav raug cais raws li ASME B31.3 kab lus.300(b)(1) hais tias, "Tus tswv kuj yog lub luag haujlwm rau kev txiav txim siab hauv chav kawm D, M, siab siab, thiab siab purity piping, thiab txiav txim siab seb puas yuav siv cov txheej txheem tshwj xeeb."
Fluid categorization txhais cov degree ntawm kev ntsuam xyuas thiab hom kev xeem yuav tsum tau, nrog rau ntau lwm yam yuav tsum tau raws li nyob rau hauv cov dej qeb.Lub luag hauj lwm ntawm tus tswv rau qhov no feem ntau yog poob rau engineering department ntawm tus tswv los yog ib tug outsourced engineer.
Thaum B31.3 Txheej Txheem Piping Code tsis qhia tus tswv yam khoom siv rau cov kua dej tshwj xeeb, nws muab kev taw qhia txog lub zog, tuab, thiab cov khoom siv sib txuas.Kuj tseem muaj ob nqe lus hauv kev taw qhia rau cov cai uas hais meej meej:
Thiab nthuav rau thawj kab lus saum toj no, kab lus B31.3.300(b)(1) kuj tau hais tias: “Tus tswv ntawm lub raj xa dej yog lub luag haujlwm nkaus xwb rau kev ua raws li Txoj Cai no thiab tsim kom muaj kev tsim, tsim, tshuaj xyuas, tshuaj xyuas, thiab kev soj ntsuam cov cai tswj hwm tag nrho cov dej tuav lossis cov txheej txheem ntawm cov kav dej yog ib feem.Installation."Yog li, tom qab tso qee cov kev cai hauv av rau kev lav phib xaub thiab cov cai rau kev txheeb xyuas cov kev pabcuam dej, cia peb pom qhov twg hydrogen gas haum rau hauv.
Vim tias cov pa roj hydrogen ua cov kua dej tsis haum nrog cov xau, cov roj hydrogen tuaj yeem suav tias yog cov kua dej ib txwm muaj lossis Class M kua hauv qeb B31.3 rau kev pabcuam ua kua.Raws li tau hais los saum toj no, kev faib tawm ntawm kev tuav cov kua dej yog tus tswv yuav tsum tau ua, yog tias nws ua tau raws li cov lus qhia rau pawg xaiv tau piav qhia hauv B31.3, kab lus 3. 300.2 Cov lus txhais hauv ntu "Kev pabcuam hydraulic".Cov hauv qab no yog cov ntsiab lus rau kev pabcuam kua dej ib txwm muaj thiab Class M fluid service:
“Kev Pabcuam Ua Kua Dej: Cov kev pabcuam kua dej siv tau rau feem ntau cov kav dej raws li txoj cai no, piv txwv li tsis raug rau cov kev cai rau cov chav kawm D, M, kub siab, siab siab, lossis dej huv.
(1) Lub toxicity ntawm cov kua dej yog heev uas ib zaug raug rau ib tug heev me me ntawm cov kua uas tshwm sim los ntawm ib tug xau tuaj yeem ua rau muaj kev raug mob loj heev rau cov neeg uas nqus tau los yog nkag mus rau nws, txawm tias tam sim ntawd rov qab ntsuas.coj
(2) Tom qab xav txog kev tsim cov raj xa dej, kev paub dhau los, kev ua haujlwm, thiab qhov chaw, tus tswv txiav txim siab tias qhov yuav tsum tau ua rau kev siv cov kua dej ib txwm muaj tsis txaus los muab qhov nruj tsim nyog los tiv thaiv cov neeg ua haujlwm los ntawm kev raug.”
Hauv cov ntsiab lus saum toj no ntawm M, hydrogen gas tsis ua raws li cov txheej txheem ntawm nqe lus (1) vim tias nws tsis suav tias yog kua tshuaj lom.Txawm li cas los xij, los ntawm kev ua raws li ntu (2), Txoj Cai tso cai rau kev faib cov tshuab hydraulic hauv chav kawm M tom qab kev txiav txim siab ntawm "… piping design, kev paub, kev ua haujlwm thiab qhov chaw ..." Tus tswv tso cai rau kev txiav txim siab ntawm kev tuav dej ib txwm muaj.Cov kev xav tau tsis txaus los ua kom tau raws li qhov yuav tsum tau ua kom muaj kev ncaj ncees ntau dua hauv kev tsim, kev tsim kho, kev tshuaj xyuas, kev tshuaj xyuas thiab kev sim ntawm hydrogen gas piping systems.
Thov xa mus rau Table 1 ua ntej tham txog Kev Kub Kub Kub Hydrogen Corrosion (HTHA).Cov lej, cov qauv, thiab cov kev cai tau teev nyob rau hauv cov lus no, uas suav nrog rau 6 cov ntaub ntawv hais txog cov ntsiab lus ntawm hydrogen embrittlement (HE), ib qho kev tsis sib haum xeeb uas muaj xws li HTHA.OH tuaj yeem tshwm sim ntawm qhov kub thiab txias.Pom tau tias yog ib daim ntawv ntawm corrosion, nws tuaj yeem pib ua ntau txoj hauv kev thiab tseem cuam tshuam rau ntau yam khoom siv.
Nws muaj ntau hom, uas tuaj yeem muab faib ua hydrogen cracking (HAC), hydrogen stress cracking (HSC), stress corrosion cracking (SCC), hydrogen corrosion cracking (HACC), hydrogen bubbling (HB), hydrogen cracking (HIC).)), kev nyuaj siab oriented hydrogen cracking (SOHIC), progressive cracking (SWC), sulfide stress cracking (SSC), soft zone cracking (SZC), and high temperature hydrogen corrosion (HTHA).
Hauv nws daim ntawv yooj yim tshaj plaws, hydrogen embrittlement yog ib txoj hauv kev rau kev puas tsuaj ntawm cov hlau lis ciam teb, uas ua rau txo qis vim qhov nkag mus ntawm atomic hydrogen.Txoj hauv kev uas qhov no tshwm sim muaj ntau yam thiab yog ib feem txhais los ntawm lawv cov npe, xws li HTHA, qhov twg ib txhij kub siab thiab siab hydrogen yog xav tau rau embrittlement, thiab SSC, qhov twg atomic hydrogen yog tsim los kaw-gases thiab hydrogen.vim acid corrosion, lawv nkag mus rau hauv cov hlau, uas tuaj yeem ua rau brittleness.Tab sis tag nrho cov txiaj ntsig zoo ib yam li rau txhua qhov xwm txheej ntawm hydrogen embrittlement tau piav qhia saum toj no, qhov twg lub zog ntawm cov hlau raug txo los ntawm embrittlement hauv qab nws qhov kev cia siab ntau yam, uas nyob rau hauv lem teeb tsa theem rau ib qho kev puas tsuaj loj uas muab lub volatility ntawm cov kua.
Ntxiv nrog rau cov phab ntsa tuab thiab kev sib koom ua ke ntawm kev sib koom ua ke, muaj ob yam tseem ceeb uas yuav tsum tau xav txog thaum xaiv cov khoom siv rau H2 roj kev pabcuam: 1. Kev kub siab hydrogen (HTHA) thiab 2. Kev txhawj xeeb hnyav txog qhov muaj peev xwm to.Ob lub ntsiab lus tam sim no nyob rau hauv kev sib tham.
Tsis zoo li molecular hydrogen, atomic hydrogen tuaj yeem nthuav dav, nthuav tawm cov hydrogen mus rau qhov kub thiab txias, tsim lub hauv paus rau HTHA muaj peev xwm.Nyob rau hauv cov xwm txheej no, atomic hydrogen muaj peev xwm diffuse mus rau hauv cov pa roj carbon steel piping cov ntaub ntawv lossis cov khoom siv, qhov uas nws hnov ​​​​mob nrog cov pa roj carbon monoxide hauv cov xim hlau los tsim cov roj methane ntawm cov ciam teb.Tsis muaj peev xwm khiav tawm, cov pa nthuav dav, tsim cov kab nrib pleb thiab cov kab nrib pleb hauv phab ntsa ntawm cov kav dej lossis cov hlab ntsha - qhov no yog HTGA.Koj tuaj yeem pom meej HTHA cov txiaj ntsig hauv daim duab 2 qhov twg cov kab nrib pleb thiab cov kab nrib pleb tshwm sim hauv 8 "phab ntsa.Ib feem ntawm nominal size (NPS) yeeb nkab uas ua tsis tau raws li cov xwm txheej no.
Cov pa roj carbon steel tuaj yeem siv rau kev pabcuam hydrogen thaum lub sijhawm ua haujlwm kub yog khaws cia qis dua 500 ° F.Raws li tau hais los saum toj no, HTHA tshwm sim thaum cov pa roj hydrogen tuav ntawm qhov siab ib nrab thiab kub siab.Cov pa roj carbon steel tsis pom zoo thaum lub hydrogen ib feem siab yuav tsum nyob ib ncig ntawm 3000 psi thiab qhov kub siab tshaj li ntawm 450 ° F (uas yog qhov xwm txheej hauv daim duab 2).
Raws li tuaj yeem pom los ntawm qhov hloov kho Nelson zaj duab xis hauv daim duab 3, ib feem coj los ntawm API 941, qhov kub thiab txias muaj qhov cuam tshuam loj tshaj plaws ntawm hydrogen forcing.Hydrogen roj ib feem siab tuaj yeem tshaj 1000 psi thaum siv cov pa roj carbon steel ua haujlwm ntawm qhov kub txog li 500 ° F.
Daim duab 3. Daim duab Nelson hloov kho no (hloov los ntawm API 941) tuaj yeem siv los xaiv cov khoom tsim nyog rau kev pabcuam hydrogen ntawm ntau qhov kub thiab txias.
Ntawm daim duab.3 qhia txog kev xaiv cov hlau uas tau lees paub kom tsis txhob muaj kev tawm tsam hydrogen, nyob ntawm qhov ua haujlwm kub thiab ib nrab siab ntawm hydrogen.Austenitic stainless hlau yog insensitive rau HTHA thiab yog cov khoom txaus siab ntawm txhua qhov kub thiab txias.
Austenitic 316/316L stainless hlau yog cov khoom siv zoo tshaj plaws rau kev siv hydrogen thiab muaj cov ntaub ntawv pov thawj.Thaum kev kho cua sov tom qab vuam (PWHT) tau pom zoo rau cov pa roj carbon steel kom calcinate residual hydrogen thaum lub sij hawm vuam thiab txo cov cua sov cuam tshuam cheeb tsam (HAZ) hardness tom qab vuam, nws tsis tas rau austenitic stainless hlau.
Thermothermal teebmeem tshwm sim los ntawm kev kho cua sov thiab vuam tsis tshua muaj kev cuam tshuam rau cov khoom ntawm austenitic stainless hlau.Txawm li cas los xij, kev ua haujlwm txias tuaj yeem txhim kho cov khoom siv ntawm austenitic stainless hlau, xws li lub zog thiab hardness.Thaum khoov thiab tsim cov kav dej los ntawm austenitic stainless hlau, lawv cov khoom siv kho tshuab hloov pauv, suav nrog kev txo qis hauv cov khoom siv plasticity.
Yog hais tias austenitic stainless hlau yuav tsum tau txias txias, kev daws annealing (kub rau kwv yees li 1045 ° C ua raws li los ntawm quenching los yog ceev ceev txias) yuav restore lub mechanical zog ntawm cov khoom mus rau lawv cov qub nqi.Nws kuj tseem yuav tshem tawm cov hlau sib cais, rhiab heev thiab sigma theem ua tiav tom qab ua haujlwm txias.Thaum ua cov tshuaj annealing, nco ntsoov tias qhov txias ceev tuaj yeem ua rau cov khoom seem rov qab rau hauv cov khoom yog tias tsis ua haujlwm zoo.
Xa mus rau cov rooj GR-2.1.1-1 Piping and Tubing Assembly Material Specification Index thiab GR-2.1.1-2 Piping Material Specification Index hauv ASME B31 rau kev xaiv cov khoom siv rau H2 kev pabcuam.cov kav dej yog qhov chaw zoo pib.
Nrog rau tus qauv atomic qhov hnyav ntawm 1.008 atomic mass units (amu), hydrogen yog lub teeb tshaj plaws thiab tsawg tshaj plaws nyob rau hauv lub sij hawm lub sij hawm, thiab yog li ntawd muaj ib tug siab propensity rau xau, muaj peev xwm ua rau muaj kev puas tsuaj loj heev, kuv yuav ntxiv.Yog li ntawd, cov kav dej xa hluav taws xob yuav tsum tau tsim nyob rau hauv xws li kev txwv kev sib txuas ntawm cov tshuab hluav taws xob thiab txhim kho cov kev sib txuas uas xav tau tiag tiag.
Thaum txwv cov ntsiab lus xau, lub kaw lus yuav tsum tau welded tag nrho, tshwj tsis yog cov flanged kev sib txuas ntawm cov khoom siv, cov kav dej thiab fittings.Cov xov sib txuas yuav tsum zam kom deb li deb tau, yog tias tsis ua tiav.Yog hais tias threaded kev twb kev txuas tsis tuaj yeem zam tau rau ib qho laj thawj, nws raug nquahu kom koom nrog lawv yam tsis muaj xov sealant thiab tom qab ntawd muab cov hlua khi.Thaum siv cov yeeb nkab carbon steel, cov yeeb nkab txuas yuav tsum tau welded thiab tom qab vuam kub kho (PWHT).Tom qab vuam, cov kav dej hauv thaj chaw muaj kev kub ntxhov (HAZ) raug cuam tshuam rau hydrogen nres txawm nyob rau ntawm qhov kub thiab txias.Thaum hydrogen nres tshwm sim feem ntau ntawm qhov kub thiab txias, PWHT theem yuav txo tau tag nrho, yog tias tsis tshem tawm, qhov no muaj peev xwm txawm tias nyob hauv ib puag ncig.
Lub ntsiab lus tsis muaj zog ntawm tag nrho cov-welded system yog kev sib txuas flange.Txhawm rau kom muaj kev nruj nruj ntawm kev sib txuas ntawm flange, Kammprofile gaskets (daim duab 4) los yog lwm hom gaskets yuav tsum tau siv.Ua nyob rau hauv yuav luag tib txoj kev los ntawm ob peb manufacturers, lub ncoo no yog heev zam txim.Nws muaj cov hniav tag nrho-hlau rings sandwiched ntawm mos, deformable sealing cov ntaub ntawv.Cov hniav mloog zoo rau lub nra ntawm lub ntsia liaj qhov rooj nyob rau hauv ib qho chaw me me los muab kev nruj nruj nrog kev ntxhov siab tsawg.Nws yog tsim nyob rau hauv xws li ib txoj kev uas nws muaj peev xwm them rau qhov tsis sib xws flange nto raws li zoo raws li cov kev khiav hauj lwm hloov pauv.
Daim duab 4. Kammprofile gaskets muaj ib tug hlau core bonded ntawm ob sab nrog ib tug mos muab tub lim.
Lwm qhov tseem ceeb ntawm kev ncaj ncees ntawm qhov system yog lub valve.Leaks ib ncig ntawm qia foob thiab lub cev flanges yog ib qho teeb meem tiag tiag.Txhawm rau tiv thaiv qhov no, nws raug nquahu kom xaiv lub valve nrog lub foob foob.
Siv 1 nti.Lub tsev kawm ntawv 80 carbon steel yeeb nkab, hauv peb qhov piv txwv hauv qab no, muab kev tsim kev kam rau siab, corrosion thiab mechanical tolerances raws li ASTM A106 Gr B, qhov siab tshaj plaws tso cai ua haujlwm siab (MAWP) tuaj yeem suav ua ob kauj ruam ntawm qhov kub txog li 300 ° F (Ceeb Toom: Qhov laj thawj rau "... rau qhov kub thiab txias txog 300ºF de 6 B ... Thaum qhov kub siab tshaj 300ºF.(S), yog li Equation (1) yuav tsum Kho kom sov siab tshaj 300ºF.)
Xa mus rau cov mis (1), thawj kauj ruam yog xam cov raj xa dej theoretical tawg siab.
T = yeeb nkab phab ntsa thickness minus mechanical, corrosion thiab manufacturing tolerances, nyob rau hauv nti.
Qhov thib ob ntawm cov txheej txheem yog xam qhov siab tshaj plaws tso cai ua haujlwm siab Pa ntawm cov raj xa dej los ntawm kev siv qhov kev nyab xeeb S f rau qhov tshwm sim P raws li qhov sib npaug (2):
Yog li, thaum siv 1 ″ tsev kawm ntawv 80 cov khoom, qhov tawg siab yog xam raws li hauv qab no:
Kev nyab xeeb Sf ntawm 4 yog tom qab ntawd siv raws li ASME Pressure Vessel Recommendations Section VIII-1 2019, Paragraph 8. UG-101 xam raws li hauv qab no:
Qhov txiaj ntsig MAWP tus nqi yog 810 psi.inch hais txog cov yeeb nkab nkaus xwb.Qhov kev sib txuas ntawm flange lossis cov khoom siv nrog qhov ntsuas qis tshaj plaws hauv qhov system yuav yog qhov kev txiav txim siab hauv kev txiav txim siab tso cai rau hauv qhov system.
Raws li ASME B16.5, qhov siab tshaj plaws ua haujlwm siab rau 150 carbon steel flange fittings yog 285 psi.nti ntawm -20 ° F txog 100 ° F.Chav kawm 300 muaj qhov siab tshaj plaws ua haujlwm siab ntawm 740 psi.Qhov no yuav yog lub siab txwv qhov tseem ceeb ntawm qhov system raws li cov khoom siv specification piv txwv hauv qab no.Tsis tas li ntawd, tsuas yog hauv kev sim hydrostatic, cov txiaj ntsig no tuaj yeem tshaj 1.5 npaug.
Raws li ib qho piv txwv ntawm cov ntsiab lus ntawm cov khoom siv carbon steel, H2 roj kev pabcuam kab specification ua haujlwm ntawm qhov kub thiab txias hauv qab qhov tsim siab ntawm 740 psi.ntiv tes, tej zaum yuav muaj cov khoom yuav tsum tau muaj nyob rau hauv Table 2. Cov nram qab no yog hom uas yuav tsum tau saib xyuas kom muaj nyob rau hauv specification:
Sib nrug los ntawm cov kav dej nws tus kheej, muaj ntau lub ntsiab lus uas tsim cov kav dej xws li fittings, li qub, cov khoom siv kab, thiab lwm yam. Txawm hais tias muaj ntau cov ntsiab lus no yuav muab tso ua ke rau hauv ib lub raj xa dej los tham txog lawv kom meej, qhov no yuav xav tau ntau nplooj ntawv ntau dua li tuaj yeem nyob.Zaj lus no.