1. Isishwankathelo Esiqhelekileyo

I-NACE MR0175/ISO 15156 ngumgangatho owaziwayo kwihlabathi liphela wokukhetha izinto zesinyithi ezisetyenziswa kwiindawo zokuvelisa ioyile negesi eziqulathe i-H₂S. Ipapashwe ngokudibeneyo yi-NACE International (ngoku eyi-AMPP) kunye ne-International Organisation for Standardization (ISO), uhlaziyo olusebenzayo lwangoku yi-ANSI/NACE MR0175-2021/ISO 15156:2020.

Ukusekwa kwalo mgangatho kuvela ekutyhaleleni kweshishini kwiindawo ezinzulu kunye nezixhobo ezikude ezikude nolwandle. Njengoko uphuhliso lwamasimi eoyile emuncu kunye negesi lusanda, ukugqwala okubangelwa yi-hydrogen sulfide kuye kwaba yinto ebaluleke kakhulu—ingakumbi i-sulfide stress cracking (SSC), enokubangela ukungaphumeleli kwe-brittle kwi-carbon enamandla aphezulu kunye neentsimbi eziphantsi kwe-alloy, nto leyo ekhokelela kwiziganeko ezimbi kakhulu.

2. Ulwakhiwo oluQhelekileyo kunye noMda

Lo mgangatho wahlulwe waba ziinxalenye ezintathu, udityaniswe kwifayile enye yePDF, kwaye uquka iiSetyhula zoBugcisa ezininzi ezipapashwe ngo-2021 nango-2022:

Inxalenye	Ububanzi	Umxholo oPhambili
Inxalenye 1	Imigaqo-siseko Jikelele	Ichaza imeko-bume emuncu, imigaqo esisiseko yokukhetha izinto, iindlela zokufaneleka
Icandelo 2	Iintsimbi zeCarbon kunye ne-Low-Alloy	Imida yokuqina (≤22 HRC), iimfuno zokuwelda, ulawulo lwekhemistri
Inxalenye 3	Ii-CRA kunye nezinye ii-Alloys	Imida yokusingqongileyo kusapho ngalunye lwe-alloy (ubushushu, i-pH₂S, uxinzelelo lwe-chloride)

Lo mgangatho usebenza kwizixhobo ezisetyenziswa kwimveliso yeoyile negesi kunye nezityalo zokuthambisa igesi yendalo apho ukungasebenzi kakuhle kunokubangela umngcipheko kwimpilo yoluntu nakubasebenzi okanye kwindalo esingqongileyo. Ujongana nazo zonke iindlela zokuqhekeka ezibangelwa yi-H₂S, kubandakanya i-SSC, i-SCC, i-HIC, i-SWC, kunye nezinye.

3. Inkcazo yeNdalo engcolileyo

Ngokomgangatho, xa uxinzelelo olungaphelelanga lwe-H₂S kwisigaba segesi ludlula i-0.3 kPa (0.05 psia), imeko-bume ihlelwa njengemuncu, nto leyo efuna ukukhethwa kwezinto ngokweemfuno zomgangatho.

Izixhobo ezisebenzayo ziquka iingcango zemithombo yamanzi, imithi yeKrismesi, iinkqubo zemibhobho, izahluli, iindlela zokuhamba kwamanzi kwiindawo zokuvelisa ezisezantsi, kunye neenkqubo zemibhobho ezithutha iihydrocarbons ezimuncu.

4. Iimfuno zeZinto eziPhambili

Iintsimbi zeCarbon kunye ne-Low-Alloy (Icandelo lesi-2)

Isinyithi esisisiseko, isinyithi esitshixiweyo, kunye nobunzima be-HAZ akufuneki budlule kwi-22 HRC (248 HV10)

Unyango lobushushu emva kokuwelda (PWHT) luyimfuneko

Ulawulo olungqongqo lwekhemistri luyafuneka

Ii-Alloys Ezingamelani Nokugqwala (Icandelo lesi-3)

Izixhobo ezifanelekileyo ziquka: i-316 SS, ii-6-moly alloys, i-2507 duplex SS, i-Alloy 825, i-Alloy 625, i-Alloy C-276, kunye ne-Alloy 400. Nganye inemida ethile yokusingqongileyo yobushushu, uxinzelelo oluyinxenye ye-H₂S, kunye noxinzelelo lwe-chloride.

5. Uhlaziyo oluPhambili kunye neMbono yexesha elizayo

Uhlelo luka-2021/2020 luye lwahlala luhambelana nohlelo luka-2003, kunye nohlaziyo oluqhubekayo ngeTechnical Circulars. Ngo-2018, iikomiti ezilawulayo zavumelana ukuba kufuneka kubhalwe ngokutsha ukuze kujongwane nokulula kokusetyenziswa kunye nokubandakanya ukuqhubela phambili kweshishini.

Inguqulelo ebhalwe ngokutsha ngokupheleleyo okwangoku iyavotelwa kwaye ipapashwa yi-ISO, yahlulwe yangamacandelo amathathu amatsha:

Inxalenye 1: Iimfuno zezinto kunye nokucubungula

Icandelo 2: Uvavanyo lwemeko yenkonzo kunye nokukhethwa kwezinto

Icandelo 3: Iimfuneko zokuqinisekisa, iziqinisekiso, kunye nokuvota

Le nguqulelo intsha inika iinkcukacha ezithe vetshe ngeenkqubo zovavanyo lwe-H₂S, kubandakanya nesikhokelo malunga nokuthatha iisampulu, ukukhethwa kwendlela yovavanyo, kunye nobungakanani bovavanyo olufunekayo ukuze kufunyanwe isiqinisekiso semveliso.

6. Ukubaluleka Okusebenzayo

I-NACE MR0175/ISO 15156 isebenza njengesiseko esisisiseko sokukhethwa kwezinto kuphuhliso lwentsimi yeoyile emuncu kunye negesi. Lo mgangatho ugxininisa ukuba akukho ntsimbi ingenasici ekhuselekile ngokupheleleyo kwi-corrosion stress-induced chloride-ukuqonda ngokupheleleyo imida ye-alloy kubalulekile ekukhetheni izinto kwiindawo ezimuncu ezifuna kakhulu. Izixhobo ezichaphazeleka kakhulu kukubola, ezifana neevalvu, izixhobo, kunye nezixhobo, zifuna ukuthotyelwa ngokungqongqo komgangatho. Zonke izixhobo zenkonzo yemuncu kufuneka zigcine ukulandeleka ngokupheleleyo, kunye nezatifikethi zovavanyo lwe-mill eziqinisekisa uvavanyo lobunzima, ukuthotyelwa kweekhemikhali, kunye nemeko yonyango lobushushu.

Kwiindawo ze-oyile negesi ezimuncu, ukukhethwa kwezinto kulandela umgangatho we-NACE MR0175 / ISO 15156. Lo mgangatho "ngumthetho wegolide" wokuqinisekisa ukusebenza ngokukhuselekileyo kwezixhobo kwiindawo ezine-hydrogen sulfide (H₂S). Ugubungela zonke izixhobo kunye nezinto eziqulathe uxinzelelo, ukusuka kwiindawo eziphantsi kwemithombo ukuya kwiiyunithi zokucubungula ezisezantsi.

Izixhobo ze-Wellhead kunye ne-downhole: izixhobo ze-wellhead, iityhubhu kunye neentambo ze-casing (iityhubhu zokuvelisa, i-casing).

Izinto zombhobho kunye nokudibanisa: umbhobho womgca osetyenziselwa ukuhanjiswa kweoyile negesi okude, umzekelo,I-API 5L grade X65 umbhobho womgca, njl. njl.

Izixhobo zokucubungula nokudlulisa umphezulu: imithambo yoxinzelelo, izahluli – izixhobo eziqulathe uxinzelelo ezisetyenziselwa ukwahlukanisa nokucubungula ioyile/igesi.

Ukongeza kwiimveliso ezingentla, umgangatho ukwagubungela iintlobo ngeentlobo zezinto, kubandakanya intsimbi yekhabhoni, intsimbi engenanto, intsimbi engatyiwayo, kunye nee-alloys ezisekelwe kwi-nickel.