Kumene Ma Vavu Amagwiritsidwa Ntchito: Kulikonse!

08 Nov 2017 Wolemba Greg Johnson

Mavavu amapezeka pafupifupi kulikonse masiku ano: m'nyumba zathu, pansi pa msewu, m'nyumba zamalonda komanso m'malo masauzande ambiri mkati mwa magetsi ndi madzi, mphero zamapepala, zoyenga, zopangira mankhwala ndi zida zina zamafakitale ndi zomangamanga.
Makampani opanga ma valve ali ndi mapewa otakata, okhala ndi magawo osiyanasiyana kuchokera kugawa madzi kupita ku mphamvu ya nyukiliya kupita kumtunda ndi kumunsi kwa mafuta ndi gasi. Iliyonse mwa mafakitale ogwiritsira ntchito mapetowa imagwiritsa ntchito mitundu ina ya ma valve; komabe, tsatanetsatane wa zomangamanga ndi zipangizo nthawi zambiri zimakhala zosiyana kwambiri. Nazi zitsanzo:

MADZI NTCHITO
M’dziko la kagawidwe ka madzi, zitsenderezo zimakhala zotsika pafupifupi nthaŵi zonse ndipo kutentha kumakhala kozungulira. Mfundo ziwirizo zogwiritsira ntchito zimalola zinthu zingapo zopangira ma valve zomwe sizikadapezeka pazida zomwe zimakhala zovuta kwambiri monga ma valve otenthetsera kutentha. Kutentha kozungulira kwa ntchito yamadzi kumalola kugwiritsa ntchito ma elastomer ndi zosindikizira za rabara zomwe siziyenera kwina. Zida zofewa izi zimalola kuti ma valve amadzi azikhala okonzeka kuti atseke zotsekera.

Kuganiziranso kwina mu ma valve operekera madzi ndikusankha muzinthu zomangira. Zitsulo zotayira ndi ductile zimagwiritsidwa ntchito kwambiri m'madzi, makamaka mizere yayikulu yakunja. Mizere yaying'ono kwambiri imatha kuyendetsedwa bwino ndi zida zamkuwa.

Kupanikizika komwe ma valve ambiri amadzi amawona nthawi zambiri amakhala pansi pa 200 psi. Izi zikutanthawuza kuti mapangidwe olimba okhala ndi mipanda yolimba sikufunika. Izi zanenedwa, nthawi zina ma valve amadzi amapangidwira kuti azitha kupanikizika kwambiri, mpaka 300 psi. Ntchitozi nthawi zambiri zimakhala pa ngalande zazitali zomwe zimakhala pafupi ndi gwero la kuthamanga. Nthawi zina ma valve amadzi othamanga kwambiri amapezekanso pamalo othamanga kwambiri mu damu lalitali.

Bungwe la American Water Works Association (AWWA) lapereka mafotokozedwe okhudza mitundu yosiyanasiyana ya ma valve ndi ma actuators omwe amagwiritsidwa ntchito popanga madzi.

MADZI ONSE
Mbali yakutsogolo ya madzi amchere omwe amalowa m'malo kapena kapangidwe kake ndi madzi otayira kapena otayira. Mizere iyi imasonkhanitsa madzi onse otaya zinyalala ndi zolimba ndikuzilozera kumalo osungira zimbudzi. Malo opangira chithandizowa amakhala ndi mapaipi otsika kwambiri komanso ma valve kuti achite "ntchito zawo zonyansa." Zofunikira za mavavu amadzi otayira nthawi zambiri ndizochepa kwambiri kuposa zomwe zimafunikira pakugwiritsa ntchito madzi oyera. Chipata chachitsulo ndi ma valve cheke ndi zosankha zodziwika kwambiri pamtundu uwu wautumiki. Ma valve okhazikika muutumikiwu amamangidwa molingana ndi mafotokozedwe a AWWA.

POWER INDUSTRY
Mphamvu zambiri zamagetsi zomwe zimapangidwa ku United States zimapangidwira m'mafakitale a nthunzi pogwiritsa ntchito mafuta opangira mafuta komanso ma turbines othamanga kwambiri. Kutsegula chivundikiro cha chopangira magetsi chamakono kungapereke mawonekedwe a makina opopera amphamvu kwambiri, otentha kwambiri. Mizere yayikuluyi ndiyofunikira kwambiri pakupanga mphamvu zamagetsi.

Ma valve a zipata amakhalabe chisankho chachikulu chamagetsi pa / off ntchito, ngakhale cholinga chapadera, ma valve a Y-pattern globe amapezekanso. Ma valve ochita masewera olimbitsa thupi, ofunikira kwambiri ayamba kutchuka ndi opanga makina opangira magetsi ndipo akulowa m'dziko lino lokhala ndi ma valve ozungulira.

Metallurgy ndi yofunika kwambiri pama valve ogwiritsira ntchito mphamvu, makamaka omwe amagwira ntchito mopitilira muyeso kapena kupitilira kwapamwamba kwambiri kwa kuthamanga ndi kutentha. F91, F92, C12A, pamodzi ndi ma Inconel angapo ndi zitsulo zosapanga dzimbiri zimagwiritsidwa ntchito kwambiri m'mafakitale amasiku ano. Makalasi opanikizika amaphatikizapo 1500, 2500 ndipo nthawi zina 4500. Kukonzekera kwa magetsi apamwamba (zomwe zimagwira ntchito pokhapokha ngati zikufunikira) zimayikanso zovuta kwambiri pa ma valve ndi mapaipi, zomwe zimafuna mapangidwe amphamvu kuti athe kuthana ndi kuphatikizika kwakukulu kwa njinga, kutentha ndi kutentha. kupanikizika.
Kuphatikiza pa ma valve akuluakulu a nthunzi, magetsi amadzaza ndi mapaipi owonjezera, okhala ndi miyandamiyanda ya zipata, globe, cheke, butterfly ndi ma valve a mpira.

Zopangira mphamvu za nyukiliya zimagwira ntchito mofanana ndi nthunzi / turbine yothamanga kwambiri. Kusiyana kwakukulu ndikuti mu malo opangira mphamvu za nyukiliya, nthunzi imapangidwa ndi kutentha kuchokera ku ndondomeko ya fission. Mavavu opangira mphamvu za nyukiliya ndi ofanana ndi apachibale awo opangidwa ndi zinthu zakale, kupatula mbadwa zawo komanso chofunikira chowonjezera chodalirika. Mavavu a nyukiliya amapangidwa mwapamwamba kwambiri, ndipo zolemba zoyenerera ndi zowunikira zimadzaza mazana amasamba.

KUPANGA MAFUTA NDI GESI
Zitsime zamafuta ndi gasi ndi malo opangira ndi ogwiritsa ntchito kwambiri ma valve, kuphatikiza ma valve ambiri olemetsa. Ngakhale kuti mafuta otuluka m'mwamba pamtunda wautali sangawonekere, chithunzichi chikuwonetsa mphamvu ya mafuta ndi gasi pansi pa nthaka. Ichi ndichifukwa chake mitu ya zitsime kapena mitengo ya Khrisimasi imayikidwa pamwamba pa chitoliro chachitali cha chitsime. Misonkhanoyi, yokhala ndi mavavu ophatikizika ndi zida zapadera, idapangidwa kuti izitha kuthana ndi zovuta zopitilira 10,000 psi. Ngakhale kuti sizipezeka kawirikawiri pazitsime zokumbidwa pamtunda masiku ano, kupanikizika kwakukulu kumapezeka nthawi zambiri pazitsime zakuya za m'mphepete mwa nyanja.

Mapangidwe a zida za Wellhead amaphimbidwa ndi API monga 6A, Specification for Wellhead ndi Khrisimasi Tree Equipment. Ma valve omwe amaphimbidwa mu 6A amapangidwira kupanikizika kwambiri koma kutentha pang'ono. Mitengo yambiri ya Khrisimasi imakhala ndi ma valve a zipata ndi ma valve apadera a globe otchedwa chokes. Zitsamwe zimagwiritsidwa ntchito kuwongolera kutuluka kwa chitsime.

Kuphatikiza pa zitsime zomwezo, malo ambiri othandizira amakhala ndi malo opangira mafuta kapena gasi. Zida zopangira zopangira mafuta kapena gasi zimafunikira ma valve angapo. Ma valve awa nthawi zambiri amakhala chitsulo cha kaboni chovotera magulu apansi.

Nthaŵi zina, madzi owononga kwambiri—hydrogen sulfide— amapezeka mumtsinje wa petroleum yaiwisi. Izi, zomwe zimatchedwanso mpweya wowawasa, zimatha kupha. Kuthana ndi zovuta zamagesi wowawasa, zida zapadera kapena njira zopangira zinthu molingana ndi NACE International specifications MR0175 ziyenera kutsatiridwa.

OFFSHORE INDUSTRY
Makina opangira mapaipi opangira mafuta akunyanja ndi malo opangira zinthu amakhala ndi ma valve ambiri omangidwa mosiyanasiyana kuti athe kuthana ndi zovuta zambiri zowongolera kuyenda. Maofesiwa alinso ndi malupu osiyanasiyana owongolera ndi zida zothandizira kupanikizika.

Pamalo opangira mafuta, mtima wapamtima ndiye njira yeniyeni yopangira mafuta kapena gasi. Ngakhale kuti sizikhala pa pulatifomu nthawi zonse, machitidwe ambiri opangira zinthu amagwiritsa ntchito mitengo ya Khrisimasi ndi mapaipi omwe amagwira ntchito mozama mozama mamita 10,000 kapena kuposerapo. Zida zopangira izi zimamangidwa pamiyezo yambiri ya American Petroleum Institute (API) ndipo zimatchulidwa muzochita zingapo zovomerezeka za API (RPs).

Pamapulatifomu ambiri amafuta, njira zowonjezera zimagwiritsidwa ntchito kumadzi obiriwira omwe amachokera pachitsime. Izi zikuphatikizapo kulekanitsa madzi kuchokera ku ma hydrocarbon ndi kulekanitsa mpweya ndi mpweya wamadzimadzi kuchokera kumadzimadzi. Mipope iyi yamtengo wa Khrisimasi nthawi zambiri imamangidwa ku American Society of Mechanical Engineers B31.3 yokhala ndi ma valve opangidwa motsatira ma valve a API monga API 594, API 600, API 602, API 608 ndi API 609.

Ena mwa machitidwewa angakhalenso ndi chipata cha API 6D, mpira ndi ma valve owunika. Popeza mapaipi aliwonse omwe ali papulatifomu kapena pobowola sitimayo ali mkati mwa malowa, zofunikira zogwiritsira ntchito mavavu a API 6D pamapaipi sizigwira ntchito. Ngakhale mitundu ingapo ya ma valve imagwiritsidwa ntchito pamapaipi awa, mtundu wa valve wosankha ndi valavu ya mpira.

MIPAPI
Ngakhale kuti mapaipi ambiri sawoneka, kupezeka kwawo nthawi zambiri kumawonekera. Zizindikiro zing'onozing'ono zonena kuti "paipi ya petroleum" ndi chizindikiro chimodzi chodziwikiratu cha kukhalapo kwa mapaipi apansi panthaka. Mapaipiwa ali ndi mavavu ambiri ofunikira pautali wawo wonse. Ma valve otseka mapaipi angozi amapezeka pakapita nthawi monga momwe zafotokozedwera ndi miyezo, ma code ndi malamulo. Mavavuwa amagwira ntchito yofunika kwambiri yopatula gawo la payipi ngati latopa kapena pakufunika kukonza.

Zinanso zobalalika panjira ya mapaipi ndi zida zomwe mzerewo umachokera pansi ndipo njira yolowera ikupezeka. Masiteshoniwa ndi nyumba ya zida zoyambira "nkhumba", zomwe zimakhala ndi zida zomwe zimayikidwa m'mapaipi kuti ziwone kapena kuyeretsa chingwe. Malo otsegulira nkhumba awa nthawi zambiri amakhala ndi ma valve angapo, kaya zipata kapena mitundu ya mpira. Mavavu onse pamapaipi ayenera kukhala ndi doko lathunthu (lotseguka kwathunthu) kuti nkhumba zidutse.

Mapaipi amafunikiranso mphamvu kuti athe kuthana ndi kugwedezeka kwa mapaipi ndikusunga kuthamanga ndi kuyenda kwa mzerewo. Makina osindikizira kapena kupopera omwe amawoneka ngati mawonekedwe ang'onoang'ono opangira makina opanda nsanja zazitali zong'ambika amagwiritsidwa ntchito. Masiteshoni awa ali ndi zipata zambiri, mpira ndi ma valve owunika mapaipi.
Mapaipiwo amapangidwa motsatira miyezo ndi ma code osiyanasiyana, pomwe mavavu a mapaipi amatsata API 6D Pipeline Valves.
Palinso mapaipi ang'onoang'ono omwe amalowera m'nyumba ndi m'nyumba zamalonda. Mizere iyi imapereka madzi ndi gasi ndipo imatetezedwa ndi ma valve otseka.
Matauni akuluakulu, makamaka kumpoto kwa United States, amapereka mpweya wotenthetsera kwa makasitomala amalonda. Mizere yoperekera nthunziyi imakhala ndi ma valve osiyanasiyana kuti athe kuwongolera ndikuwongolera kutulutsa kwa nthunzi. Ngakhale madzimadzi ndi nthunzi, kupanikizika ndi kutentha kumakhala kotsika kusiyana ndi zomwe zimapezeka mumagetsi opangira nthunzi. Mitundu yosiyanasiyana ya ma valve imagwiritsidwa ntchito muutumikiwu, ngakhale valavu yolemekezeka ya plug akadali chisankho chodziwika.

KUYERETSA NDI PETROCHEMICAL
Ma valve oyeretsera amagwiritsa ntchito ma valve ambiri a mafakitale kuposa gawo lina lililonse. Malo oyeretsera amakhala ndi madzi owononga komanso nthawi zina kutentha kwambiri.
Zinthu izi zimapanga momwe ma valve amapangidwira motsatira ndondomeko ya mapangidwe a valve API monga API 600 (mavavu apachipata), API 608 (ma valve a mpira) ndi API 594 (check valves). Chifukwa cha ntchito yovuta yomwe ma valve ambiri amakumana nawo, ndalama zowonjezera zowonongeka nthawi zambiri zimafunika. Chilolezochi chikuwonetsedwa kudzera mu makulidwe akulu a khoma omwe amafotokozedwa muzolemba zamapangidwe a API.

Pafupifupi mtundu uliwonse wa valavu ukhoza kupezeka mochulukira m'malo oyeretsera. Valavu yachipata yopezeka paliponse ikadali mfumu ya phiri lomwe lili ndi anthu ambiri, koma ma valve otembenuka akutenga gawo lalikulu pamsika wawo. Zogulitsa zomwe zikuyenda bwino m'makampaniwa (omwe kale anali olamulidwa ndi zinthu zopanga mizere) amaphatikiza ma valve agulugufe okhala ndi zitsulo zokhala ndi zitsulo.

Chipata chokhazikika, globe ndi ma cheke ma valve akupezekabe, ndipo chifukwa cha kukhudzika kwa mapangidwe awo ndi chuma cha kupanga, sizidzatha posachedwa.
Kupanikizika kwa mavavu oyeretsera kumayendetsa masewerawa kuchokera ku Class 150 mpaka Class 1500, ndipo Gulu la 300 ndilodziwika kwambiri.
Zitsulo zopanda kaboni, monga giredi WCB (zoponyedwa) ndi A-105 (zopanga) ndizo zida zodziwika bwino zomwe zimatchulidwa ndikugwiritsidwa ntchito m'mavavu poyeretsa. Ntchito zambiri zoyenga zimakankhira malire a kutentha kwa zitsulo za carbon plain, ndipo ma aloyi a kutentha kwapamwamba amaperekedwa kwa izi. Zodziwika kwambiri mwa izi ndizitsulo za chrome / moly monga 1-1 / 4% Cr, 2-1 / 4% Cr, 5% Cr ndi 9% Cr. Zitsulo zosapanga dzimbiri ndi ma aloyi a nickel apamwamba amagwiritsidwanso ntchito m'njira zina mwankhanza kwambiri zoyenga.

CHEMICAL
Makampani opanga mankhwala ndi ogwiritsa ntchito kwambiri ma valve amitundu yonse ndi zida. Kuchokera ku zomera zazing'ono mpaka kuzinthu zazikulu za petrochemical zomwe zimapezeka ku Gulf Coast, ma valve ndi gawo lalikulu la makina opangira makina.

Ntchito zambiri m'machitidwe amankhwala zimakhala zotsika kwambiri kuposa njira zambiri zoyenga komanso kupanga mphamvu. Magulu othamanga kwambiri a ma valve opangira mankhwala ndi mapaipi ndi Makalasi 150 ndi 300. Zomera za Chemical zakhalanso zoyendetsa kwambiri pamsika zomwe ma valve a mpira adalimbana ndi ma valve ozungulira zaka 40 zapitazi. Valavu yokhazikika yokhala ndi mpira, yokhala ndi zero-leakage shutoff, ndiyoyenera kugwiritsa ntchito mbewu zambiri zama mankhwala. Kukula kophatikizana kwa valve ya mpira ndi chinthu chodziwika bwino.
Palinso zomera zina za mankhwala ndi zomera zomwe ma valve ozungulira amawakonda. Pazifukwa izi, ma valve opangidwa ndi API 603 odziwika, okhala ndi makoma ocheperako komanso zolemera zopepuka, nthawi zambiri amakhala chipata kapena valavu ya globe yosankha. Kuwongolera mankhwala ena kumathekanso bwino ndi diaphragm kapena pinch valves.
Chifukwa cha kuwonongeka kwa mankhwala ambiri ndi njira zopangira mankhwala, kusankha zinthu ndizofunikira. Zida za defacto ndi kalasi ya 316/316L yachitsulo chosapanga dzimbiri cha austenitic. Izi zimagwira ntchito bwino polimbana ndi dzimbiri kuchokera kumadzi ambiri nthawi zina oipa.

Pazinthu zina zowononga zowonongeka, chitetezo chowonjezereka chimafunika. Makalasi ena apamwamba kwambiri achitsulo chosapanga dzimbiri cha austenitic, monga 317, 347 ndi 321 nthawi zambiri amasankhidwa muzochitika izi. Ma alloys ena omwe amagwiritsidwa ntchito nthawi ndi nthawi kuwongolera madzi amadzimadzi amaphatikiza Monel, Alloy 20, Inconel ndi 17-4 PH.

LNG NDI KULEKANA GESI
Magesi achilengedwe amadzimadzi (LNG) komanso njira zomwe zimafunikira pakulekanitsa gasi zimadalira mapaipi ambiri. Mapulogalamuwa amafuna ma valve omwe amatha kugwira ntchito pa kutentha kochepa kwambiri kwa cryogenic. Makampani a LNG, omwe akukula kwambiri ku United States, akuyang'ana mosalekeza kukweza ndi kukonza njira yopangira mafuta a gasi. Kuti izi zitheke, mapaipi ndi ma valve akhala akukulirakulira ndipo zofunikira zamphamvu zakwezedwa.

Izi zafuna opanga ma valve kupanga mapangidwe kuti akwaniritse magawo olimba. Mpira wa quarter-turn ndi ma valve a butterfly ndi otchuka pa ntchito ya LNG, ndi 316ss [zitsulo zosapanga dzimbiri] zomwe zimakonda kwambiri. ANSI Class 600 ndiye denga lanthawi zonse lamphamvu pamagwiritsidwe ambiri a LNG. Ngakhale zinthu za kotala ndi mitundu yodziwika bwino ya ma valve, chipata, globe ndi ma valve owunika amapezekanso muzomera.

Ntchito yolekanitsa gasi imaphatikizapo kugawa gasi kukhala zinthu zake zofunika. Mwachitsanzo, njira zolekanitsa mpweya zimatulutsa nitrogen, oxygen, helium ndi mpweya wina wotsatira. Kutentha kwambiri kwa ndondomekoyi kumatanthauza kuti ma valve ambiri a cryogenic amafunika.

Zomera zonse za LNG komanso zolekanitsa gasi zimakhala ndi ma valve otsika kwambiri omwe ayenera kukhala ogwiritsidwa ntchito muzochitika za cryogenic. Izi zikutanthauza kuti makina opangira ma valve ayenera kukwezedwa kutali ndi madzi otentha otentha pogwiritsa ntchito mpweya kapena mpweya wotsekemera. Mpweya wa mpweya umenewu umalepheretsa madziwo kuti asapange mpira woundana kuzungulira malo onyamula, zomwe zingalepheretse tsinde la valve kutembenuka kapena kukwera.

NYUMBA ZA NTCHITO
Nyumba zamalonda zimatizinga koma pokhapokha ngati titatchera khutu pamene akumangidwa, sitidziwa zambiri za mitsempha yamadzimadzi yobisika mkati mwa makoma awo a miyala, magalasi ndi zitsulo.

Chofanana m'nyumba iliyonse ndi madzi. Mapangidwe onsewa ali ndi machitidwe osiyanasiyana a mapaipi omwe amanyamula mitundu yambiri ya hydrogen / oxygen compound monga madzi otsekemera, madzi oipa, madzi otentha, madzi a imvi ndi chitetezo cha moto.

Pankhani yopulumuka yanyumba, zozimitsa moto ndizofunikira kwambiri. Chitetezo chamoto m'nyumba chimadyetsedwa pafupifupi padziko lonse lapansi ndikudzazidwa ndi madzi oyera. Kuti machitidwe amadzi amoto akhale ogwira mtima, ayenera kukhala odalirika, kukhala ndi mphamvu zokwanira komanso kukhala momasuka ponseponse. Makinawa adapangidwa kuti azingopatsa mphamvu ngati moto wayaka.
Nyumba zazitali zimafuna kuti madzi azithamanga m’mwamba monga momwe zilili pansi kotero kuti mapampu amphamvu kwambiri ndi mapaipi ayenera kugwiritsidwa ntchito kuti madziwo akwere. Mipope nthawi zambiri imakhala Class 300 kapena 600, kutengera kutalika kwa nyumba. Mitundu yonse ya ma valve imagwiritsidwa ntchito pazifukwa izi; Komabe, mapangidwe a valve ayenera kuvomerezedwa ndi Underwriters Laboratories kapena Factory Mutual pa ntchito yaikulu yamoto.

Makalasi omwewo ndi mitundu ya ma valve omwe amagwiritsidwa ntchito pazitsulo zamoto amagwiritsidwa ntchito pogawa madzi akumwa, ngakhale kuti kuvomereza sikuli kovuta.
Makina owongolera mpweya wamalonda omwe amapezeka m'mabizinesi akuluakulu monga nyumba zamaofesi, mahotela ndi zipatala nthawi zambiri amakhala pakati. Ali ndi chiller chachikulu kapena boiler kuti aziziziritsa kapena kutentha madzimadzi omwe amagwiritsidwa ntchito kusamutsa kuzizira kapena kutentha kwambiri. Makinawa nthawi zambiri amayenera kunyamula mafiriji monga R-134a, hydro-fluorocarbon, kapena ngati pali zida zazikulu zotenthetsera, nthunzi. Chifukwa chakukula kwa agulugufe ndi mavavu a mpira, mitundu iyi yadziwika kwambiri pamakina oziziritsa a HVAC.

Kumbali ya nthunzi, ma valve ena otembenukira ku kotala ayamba kugwiritsidwa ntchito, komabe mainjiniya ambiri opangira mapaipi amadalirabe ma valve olowera pachipata ndi ma globe, makamaka ngati mapaipi amafunikira nsonga zowotcherera. Pogwiritsa ntchito nthunzi pang'onopang'ono, chitsulo chatenga malo chifukwa cha chitsulo chowotcherera.

Makina ena otenthetsera amagwiritsa ntchito madzi otentha m'malo mwa nthunzi ngati madzi otumizira. Machitidwewa amathandizidwa bwino ndi ma valve amkuwa kapena chitsulo. Mavavu okhala ndi agulugufe okhala ndi ma quarter-turn-turn resilient ndi otchuka kwambiri, ngakhale kuti mapangidwe ena amzere amagwiritsidwabe ntchito.

MAPETO
Ngakhale umboni wa ma valve omwe atchulidwa m'nkhaniyi sangawonekere paulendo wopita ku Starbucks kapena kunyumba ya agogo, ma valve ena ofunika kwambiri amakhala pafupi nthawi zonse. Palinso ma valve mu injini ya galimoto yomwe amagwiritsidwa ntchito popita kumalo amenewo monga aja omwe ali mu kabureta omwe amawongolera kutuluka kwa mafuta mu injini ndi aja omwe amawongolera kutuluka kwa mafuta m'mapistoni ndi kutulukanso. Ndipo ngati mavavu amenewo sali pafupi mokwanira ndi moyo wathu watsiku ndi tsiku, lingalirani zenizeni kuti mitima yathu imagunda pafupipafupi kudzera pazida zinayi zofunika kwambiri zowongolera kuyenda.

Ichi ndi chitsanzo china cha zenizeni kuti: ma valve alidi paliponse. VM
Gawo II la nkhaniyi likukhudzana ndi mafakitale owonjezera omwe ma valve amagwiritsidwa ntchito. Pitani pa www.valvemagazine.com kuti muwerenge za zamkati ndi mapepala, ntchito zam'madzi, madamu ndi mphamvu zamagetsi zamagetsi, dzuwa, chitsulo ndi chitsulo, mlengalenga, geothermal, ndi craft brewing and distilling.

GREG JOHNSON ndi purezidenti wa United Valve (www.unitedvalve.com) ku Houston. Iye ndi mkonzi wothandizira ku VALVE Magazine, wapampando wakale wa Valve Repair Council komanso membala wa board ya VRC pano. Amagwiranso ntchito pa VMA's Education & Training Committee, ndi wachiwiri kwa wapampando wa VMA's Communications Committee ndipo ndi purezidenti wakale wa Manufacturers Standardization Society.