1 Mfundo zazikulu pakusankha ma valavu

1.1 Fotokozani cholinga cha valavu mu chipangizo kapena chipangizocho

Dziwani momwe valavu imagwirira ntchito: mtundu wa sing'anga yoyenera, kuthamanga kwa ntchito, kutentha kwa ntchito ndi njira yowongolera magwiridwe antchito, ndi zina zotero;

1.2 Sankhani mtundu wa valavu molondola

Kusankha koyenera kwa mtundu wa valavu kumadalira kumvetsetsa kwathunthu kwa wopanga njira yonse yopangira ndi momwe amagwirira ntchito. Posankha mtundu wa valavu, wopanga ayenera choyamba kudziwa bwino kapangidwe kake ndi momwe valavu iliyonse imagwirira ntchito;

1.3 Dziwani kulumikizidwa kwa valavu kumapeto

Pakati pa maulumikizidwe olumikizidwa ndi ulusi, kulumikizana kwa flange ndi kulumikizana kwa malekezero a welding, awiri oyamba ndi omwe amagwiritsidwa ntchito kwambiri. Ma valve okhala ndi ulusi makamaka ndi ma valve okhala ndi mainchesi osakwana 50mm. Ngati kukula kwa mainchesi ndi kwakukulu kwambiri, kukhazikitsa ndi kutseka kulumikizana kumakhala kovuta kwambiri. Ma valve olumikizidwa ndi flange ndi osavuta kuyika ndikuchotsa, koma ndi olemera komanso okwera mtengo kuposa ma valve olumikizidwa ndi ulusi, kotero ndi oyenera kulumikizana ndi mapaipi a mainchesi ndi kupsinjika kosiyanasiyana. Maulumikizidwe a welding ndi oyenera mikhalidwe yolemera ndipo ndi odalirika kuposa maulumikizidwe a flange. Komabe, n'kovuta kumasula ndikuyikanso ma valve olumikizidwa ndi welding, kotero kugwiritsidwa ntchito kwake kumangokhala pazochitika zomwe nthawi zambiri zimatha kugwira ntchito modalirika kwa nthawi yayitali, kapena mikhalidwe yogwiritsira ntchito ndi yovuta komanso kutentha kumakhala kwakukulu;

1.4 Kusankha zipangizo za valavu

Kuwonjezera pa kuganizira za makhalidwe enieni (kutentha, kupanikizika) ndi makhalidwe a mankhwala (kuwonongeka) kwa chinthu chogwirira ntchito, ukhondo wa chinthucho (kaya pali tinthu tolimba) uyenera kuganiziridwa bwino posankha zinthu za chipolopolo cha valavu, ziwalo zamkati ndi pamwamba pake potseka. Kuphatikiza apo, malamulo oyenera a boma ndi dipatimenti yogwiritsa ntchito ayenera kufotokozedwa. Kusankha koyenera komanso koyenera kwa zinthu za valavu kungapangitse moyo wosavuta kwambiri wautumiki komanso magwiridwe antchito abwino kwambiri a valavu. Dongosolo losankha la zinthu za thupi la valavu ndi: chitsulo chopangidwa ndi chitsulo-kaboni-chitsulo chosapanga dzimbiri, ndipo dongosolo losankha la zinthu zotsekera mphete ndi: chitsulo cha rabara-mkuwa-alloy-F4;

1.5 Zina

Kuphatikiza apo, kuchuluka kwa madzi omwe akuyenda mu valavu kuyenera kudziwika, ndipo valavu yoyenera iyenera kusankhidwa pogwiritsa ntchito zomwe zilipo (monga makatalogu azinthu za valavu, zitsanzo zazinthu za valavu, ndi zina zotero).

2 Chiyambi cha Ma Vavu Ofanana

Pali mitundu yambiri ya ma valve, ndipo mitundu yake ndi yovuta. Mitundu yayikulu ndimavavu a chipata, ma valve oletsa, ma valve oletsa kutsekeka,mavavu a gulugufe, ma valve olumikizira, ma valve a mpira, ma valve amagetsi, ma valve a diaphragm, ma valve owunikira, ma valve achitetezo, ma valve ochepetsa kupanikizika,mipanda ya nthunzi ndi ma valve otseka mwadzidzidzi,Pakati pawo omwe amagwiritsidwa ntchito kwambiri ndi ma valve a chipata, ma valve oimitsa, ma valve opondereza, ma valve olumikizira, ma valve a gulugufe, ma valve a mpira, ma valve owunikira, ndi ma valve a diaphragm.

2.1 Valavu ya Chipata

Valavu ya chipata ndi valavu yomwe thupi lake lotsegula ndi kutseka (mbale ya valavu) imayendetsedwa ndi tsinde la valavu ndipo imayenda mmwamba ndi pansi pamwamba pa mpando wa valavu, womwe ungalumikize kapena kudula njira ya madzi. Poyerekeza ndi valavu yoyimitsa, valavu ya chipata imakhala ndi magwiridwe antchito abwino otsekera, kukana madzi pang'ono, khama lochepa potsegula ndi kutseka, ndipo ili ndi magwiridwe antchito ena osintha. Ndi imodzi mwa mavavu otseka omwe amagwiritsidwa ntchito kwambiri. Zoyipa zake ndi kukula kwakukulu, kapangidwe kovuta kuposa valavu yoyimitsa, kusweka kosavuta kwa pamwamba potseka, komanso kukonza kovuta. Nthawi zambiri sikoyenera kugwedezeka. Malinga ndi malo a ulusi pa tsinde la valavu ya chipata, imatha kugawidwa m'mitundu iwiri: mtundu wa tsinde lokwera ndi mtundu wa tsinde lobisika. Malinga ndi mawonekedwe a thabwa la chipata, imatha kugawidwa m'mitundu iwiri: mtundu wa wedge ndi mtundu wofanana.

2.2 Valavu yoyimitsa

Vavu yoyimitsa ndi valavu yotsekera pansi, momwe magawo otsegulira ndi otsekera (disiki ya valavu) amayendetsedwa ndi tsinde la valavu kuti ayende mmwamba ndi pansi motsatira mzere wa mpando wa valavu (pamwamba potsekera). Poyerekeza ndi valavu ya chipata, ili ndi magwiridwe antchito abwino osinthira, magwiridwe antchito osatseka bwino, kapangidwe kosavuta, kupanga ndi kukonza kosavuta, kukana madzi ambiri, komanso mtengo wotsika. Ndi valavu yodulidwa yomwe imagwiritsidwa ntchito kwambiri, yomwe imagwiritsidwa ntchito kwambiri pamapaipi apakati ndi ang'onoang'ono.

2.3 Valavu ya mpira

Zigawo zotsegulira ndi zotseka za valavu ya mpira ndi zipilala zokhala ndi mabowo ozungulira, ndipo zipilalazo zimazungulira ndi tsinde la valavu kuti zitseguke ndi kutseka kwa valavu. Vavu ya mpira ili ndi kapangidwe kosavuta, kusinthana mwachangu, kugwira ntchito mosavuta, kukula kochepa, kulemera kopepuka, zigawo zochepa, kukana madzi pang'ono, kutseka bwino, komanso kusamalira kosavuta.

2.4 Valavu yotsekera

Kupatula diski ya valavu, valavu ya throttle ili ndi kapangidwe kofanana ndi valavu yoyimitsa. Disk yake ya valavu ndi gawo lothandizira kupondaponda, ndipo mawonekedwe osiyanasiyana ali ndi mawonekedwe osiyanasiyana. M'mimba mwake mwa mpando wa valavu sayenera kukhala yayikulu kwambiri, chifukwa kutalika kwake kotseguka ndi kochepa ndipo kuthamanga kwapakati kumawonjezeka, motero kumawonjezera kuwonongeka kwa diski ya valavu. valavu ya throttle ili ndi miyeso yaying'ono, kulemera kopepuka, komanso magwiridwe antchito abwino osinthira, koma kulondola kosinthira sikokwera kwambiri.

2.5 Valavu yolumikizira

Vavu yolumikizira imagwiritsa ntchito thupi la pulagi yokhala ndi dzenje lotulukira ngati gawo lotsegulira ndi kutseka, ndipo thupi la pulagi limazungulira ndi tsinde la valavu kuti litsegule ndi kutseka. Vavu yolumikizira ili ndi kapangidwe kosavuta, kutsegula ndi kutseka mwachangu, kugwira ntchito mosavuta, kukana madzi pang'ono, zigawo zochepa, komanso kulemera kopepuka. Mavavu olumikizira amapezeka m'mitundu yolunjika, ya njira zitatu, ndi ya njira zinayi. Mavavu olumikizira olunjika amagwiritsidwa ntchito kudula sing'anga, ndipo mavavu olumikizira olunjika atatu ndi ya njira zinayi amagwiritsidwa ntchito kusintha njira ya sing'anga kapena kupotoza sing'anga.

2.6 Valavu ya gulugufe

Vavu ya gulugufe ndi mbale ya gulugufe yomwe imazungulira 90° mozungulira mzere wokhazikika m'thupi la valavu kuti imalize ntchito yotsegulira ndi kutseka. Vavu ya gulugufe ndi yaying'ono kukula kwake, yopepuka kulemera kwake, yosavuta kapangidwe kake, ndipo ili ndi zigawo zochepa chabe.

Ndipo imatha kutsegulidwa ndi kutsekedwa mwachangu pozungulira 90°, ndipo imakhala yosavuta kugwira ntchito. Valavu ya gulugufe ikatsegulidwa bwino, makulidwe a mbale ya gulugufe ndiye okhawo omwe amalimbana ndi cholumikiziracho pamene chikuyenda m'thupi la valavu. Chifukwa chake, kutsika kwa kuthamanga komwe kumapangidwa ndi valavu kumakhala kochepa kwambiri, kotero imakhala ndi mawonekedwe abwino owongolera kuyenda. Mavavu a gulugufe amagawidwa m'mitundu iwiri yotseka: chisindikizo chofewa chosalala ndi chisindikizo cholimba chachitsulo. Pa mavavu otseka, mphete yotseka imatha kuyikidwa m'thupi la valavu kapena kulumikizidwa kumphepete kwa mbale ya gulugufe. Ili ndi magwiridwe antchito abwino otseka ndipo ingagwiritsidwe ntchito potseka, komanso mapaipi opumira apakati ndi zombo zowononga. Mavavu okhala ndi zisindikizo zachitsulo nthawi zambiri amakhala ndi moyo wautali kuposa mavavu okhala ndi zisindikizo zosalala, koma zimakhala zovuta kutseka kwathunthu. Nthawi zambiri amagwiritsidwa ntchito nthawi zina pomwe kutsika kwa kuyenda ndi kupanikizika kumasiyana kwambiri ndipo magwiridwe antchito abwino otseka amafunika. Zisindikizo zachitsulo zimatha kusintha kutentha kwambiri, pomwe zisindikizo zosalala zimakhala ndi vuto lochepa chifukwa cha kutentha.

2.7 Valavu yowunikira

Valavu yowunikira ndi valavu yomwe imatha kuletsa madzi kubwerera m'mbuyo. Valavu yowunikira ya valavu yowunikira imatsegulidwa chifukwa cha kuthamanga kwa madzi, ndipo madziwo amatuluka kuchokera kumbali yolowera kupita kumbali yotulutsira. Pamene kuthamanga kwa mbali yolowera kuli kotsika kuposa komwe kuli kumbali yotulutsira, valavu yowunikira imatseka yokha chifukwa cha zinthu monga kusiyana kwa kuthamanga kwa madzi ndi mphamvu yake yokoka kuti madzi asabwerere m'mbuyo. Malinga ndi kapangidwe kake, imagawidwa mu valavu yowunikira yokweza ndi valavu yowunikira yozungulira. Valavu yowunikira yokweza imakhala ndi kutseka bwino kuposa valavu yowunikira yozungulira komanso kukana kwakukulu kwa madzi. Pa doko loyamwa la payipi yoyamwa ya pompo, valavu ya phazi iyenera kusankhidwa. Ntchito yake ndi iyi: kudzaza payipi yolowera ya pompo ndi madzi musanayambe pompo; kusunga payipi yolowera ndi thupi la pompo litadzaza ndi madzi mutayimitsa pompo pokonzekera kuyatsanso. Valavu ya phazi nthawi zambiri imayikidwa pa payipi yoyima pamalo olowera pompo, ndipo yapakati imayenda kuchokera pansi kupita pamwamba.

2.8 Valavu ya diaphragm

Gawo lotsegulira ndi kutseka la valavu ya diaphragm ndi valavu ya rabara, yomwe imayikidwa pakati pa thupi la valavu ndi chivundikiro cha valavu.

Gawo lotulukira la diaphragm limakhazikika pa tsinde la valavu, ndipo thupi la valavu limakutidwa ndi rabala. Popeza cholumikiziracho sichilowa mkati mwa chivundikiro cha valavu, tsinde la valavu silifunikira bokosi lodzaza. Vavu ya diaphragm ili ndi kapangidwe kosavuta, magwiridwe antchito abwino otsekera, kusamalitsa kosavuta, komanso kukana madzi pang'ono. Mavavu a diaphragm amagawidwa m'mitundu yosiyanasiyana, mitundu yolunjika, mitundu yolondola ndi mtundu wa current yolunjika.

3 Malangizo odziwika bwino osankha ma valavu

3.1 Malangizo osankha ma valavu a chipata

Kawirikawiri, ma valve a chipata ayenera kusankhidwa kaye. Kuwonjezera pa nthunzi, mafuta ndi zinthu zina zolumikizira, ma valve a chipata ndi oyeneranso zinthu zolumikizira zokhala ndi zinthu zolimba komanso kukhuthala kwakukulu, ndipo ndi oyenera ma valve otulutsira mpweya ndi makina otsika a vacuum. Pa zinthu zolumikizira zokhala ndi tinthu tating'onoting'ono tolimba, thupi la valve ya chipata liyenera kukhala ndi bowo limodzi kapena awiri oyeretsera. Pa zinthu zolumikizira kutentha kochepa, valavu yapadera ya chipata iyenera kusankhidwa.

3.2 Malangizo osankha ma valavu oyimitsa

Valavu yoyimitsa ndi yoyenera mapaipi omwe ali ndi zofunikira zochepa zotsutsana ndi madzi, ndiko kuti, kutayika kwa kuthamanga sikuganiziridwa kwambiri, komanso mapaipi kapena zida zomwe zili ndi zinthu zotentha kwambiri komanso zopanikizika kwambiri. Ndi yoyenera mapaipi a nthunzi ndi zina zolumikizira ndi DN < 200mm; mavavu ang'onoang'ono amatha kugwiritsa ntchito mavavu oyimitsa, monga mavavu a singano, mavavu a zida, mavavu oyesera zitsanzo, mavavu oyesera kuthamanga, ndi zina zotero; mavavu oyimitsa ali ndi malamulo oyendetsera kuyenda kapena malamulo oyendetsera kuthamanga, koma kulondola kwa malamulo sikokwera kwambiri, ndipo m'mimba mwake wa mapaipi ndi wochepa, kotero mavavu oyimitsa kapena mavavu othamanga ayenera kusankhidwa; pa zinthu zowononga kwambiri, mavavu oyimitsa otsekedwa ndi bellows ayenera kusankhidwa; koma mavavu oyimitsa sayenera kugwiritsidwa ntchito pa zinthu zolumikizira zomwe zili ndi kukhuthala kwakukulu komanso zinthu zolumikizira zomwe zili ndi tinthu tosavuta kugwetsa, komanso sayenera kugwiritsidwa ntchito ngati mavavu otulutsa mpweya ndi mavavu azinthu zotulutsa mpweya zochepa.

3.3 Malangizo osankha ma valavu a mpira

Ma valve a mpira ndi oyenera kugwiritsa ntchito zinthu zotentha pang'ono, zopanikizika kwambiri, komanso zokhuthala kwambiri. Ma valve ambiri a mpira angagwiritsidwe ntchito m'malo olumikizirana okhala ndi tinthu tolimba tomwe timapachikidwa, ndipo angagwiritsidwenso ntchito pazinthu zopukutira ndi zopukutira malinga ndi zofunikira za chisindikizo; ma valve a mpira a full-channel si oyenera kuyendetsa kayendedwe ka madzi, koma ndi oyenera nthawi zina zomwe zimafuna kutsegulidwa ndi kutsekedwa mwachangu, zomwe zimakhala zosavuta kuzimitsa mwadzidzidzi pakagwa ngozi; ma valve a mpira nthawi zambiri amalimbikitsidwa pa mapaipi okhala ndi magwiridwe antchito okhwima, kuwonongeka, njira zocheperako, kutseguka ndi kutseka mwachangu, kudula kwamphamvu (kusiyana kwakukulu kwa kuthamanga), phokoso lotsika, kupangika kwa mpweya, mphamvu yaying'ono yogwirira ntchito, komanso kukana madzi pang'ono; ma valve a mpira ndi oyenera nyumba zopepuka, kudula kwamphamvu, komanso zowononga; ma valve a mpira ndi omwenso ndi ma valve abwino kwambiri pa zinthu zotentha pang'ono komanso zozizira kwambiri. Pa makina a mapaipi ndi zida zolumikizira zotentha pang'ono, ma valve a mpira otentha pang'ono okhala ndi zophimba za valve ayenera kusankhidwa; mukamagwiritsa ntchito ma valve oyandama, zida za mpando wa valve ziyenera kunyamula katundu wa mpira ndi malo ogwirira ntchito. Ma valve a mpira akuluakulu amafunikira mphamvu zambiri akamagwira ntchito, ndipo ma valve a mpira a DN≥200mm ayenera kugwiritsa ntchito zida zotumizira nyongolotsi; ma valve a mpira okhazikika ndi oyenera nthawi yokhala ndi mainchesi akuluakulu komanso kupsinjika kwakukulu; kuphatikiza apo, ma valve a mpira omwe amagwiritsidwa ntchito pa mapaipi okhala ndi zinthu zoopsa kwambiri komanso zoyatsira moto ayenera kukhala ndi zomangamanga zoteteza moto komanso zotsutsana ndi static.

3.4 Malangizo Osankhira Valavu Yotsekera

Ma valve otsekereza ndi oyenera nthawi zomwe kutentha kwapakati ndi kuthamanga kwambiri, ndipo ndi oyenera zinthu zomwe zimafunika kusintha kayendedwe ka madzi ndi kuthamanga. Sizoyenera malo olumikizirana okhala ndi kukhuthala kwakukulu komanso okhala ndi tinthu tolimba, ndipo si oyenera ma valve odzipatula.

3.5 Malangizo Osankhira Valve Yolumikizira

Ma valve olumikizira ndi oyenera nthawi zomwe zimafuna kutsegulidwa ndi kutsekedwa mwachangu. Kawirikawiri si oyenera kugwiritsa ntchito nthunzi ndi kutentha kwambiri. Amagwiritsidwa ntchito pa zinthu zomwe zimakhala ndi kutentha kochepa komanso kukhuthala kwakukulu, komanso ndi oyenera kugwiritsa ntchito zinthu zomwe zili ndi tinthu tomwe timapachikidwa.

3.6 Malangizo Osankhira Valavu ya Gulugufe

Ma valve a gulugufe ndi oyenera nthawi yokhala ndi mainchesi akuluakulu (monga DN﹥600mm) komanso kutalika kwa kapangidwe kake, komanso nthawi zomwe zimafuna kulamulira kayendedwe ka madzi ndi kutsegula ndi kutseka mwachangu. Nthawi zambiri amagwiritsidwa ntchito pazinthu monga madzi, mafuta ndi mpweya wopanikizika wokhala ndi kutentha kwa ≤80℃ ndi kupsinjika kwa ≤1.0MPa; popeza ma valve a gulugufe ali ndi kutayika kwakukulu kwa kupanikizika poyerekeza ndi ma valve a chipata ndi ma valve a mpira, ma valve a gulugufe ndi oyenera makina apaipi omwe ali ndi kutayika kochepa kwa kupanikizika.

3.7 Malangizo Osankhira Valve Yoyang'anira

Ma valve oyesera nthawi zambiri amakhala oyenera kugwiritsa ntchito malo oyera, ndipo sayenera kugwiritsa ntchito malo okhala ndi tinthu tolimba komanso kukhuthala kwakukulu. Ngati DN≤40mm, ndibwino kugwiritsa ntchito valavu yoyezera zokweza (yomwe imaloledwa kuyikidwa pamapaipi opingasa okha); ngati DN＝50～400mm, ndibwino kugwiritsa ntchito valavu yoyezera zokweza (ikhoza kuyikidwa pamapaipi opingasa komanso oimirira. Ngati yayikidwa pa chitoliro choyima, njira yoyendera yapakati iyenera kuyambira pansi mpaka pamwamba); ngati DN≥450mm, ndibwino kugwiritsa ntchito valavu yoyezera zotetezera; ngati DN＝100～400mm, valavu yoyezera zophimba ingagwiritsidwenso ntchito; valavu yoyezera zozungulira ingapangidwe kukhala yogwira ntchito kwambiri, PN imatha kufika 42MPa, ndipo ikhoza kugwiritsidwa ntchito pa malo aliwonse ogwirira ntchito komanso kutentha kulikonse kogwirira ntchito malinga ndi zipangizo zosiyanasiyana za chipolopolo ndi zisindikizo. Malo oyezera ndi madzi, nthunzi, gasi, malo owononga, mafuta, mankhwala, ndi zina zotero. Kutentha kwapakati kogwirira ntchito kuli pakati pa -196～800℃.

3.8 Malangizo osankha ma valavu a diaphragm

Ma valve a diaphragm ndi oyenera mafuta, madzi, acidic media ndi media yokhala ndi zinthu zopachikidwa zomwe kutentha kwake kuli pansi pa 200℃ ndi kupanikizika kochepera 1.0MPa, koma osati ma organic solvents ndi ma oxidants amphamvu. Ma valve a diaphragm amtundu wa Weir ndi oyenera ma abrasive granular media. Tebulo lodziwika bwino la kayendedwe ka madzi liyenera kugwiritsidwa ntchito posankha ma valve a diaphragm amtundu wa weir. Ma valve a diaphragm olunjika ndi oyenera madzi okhuthala, simenti yonyowa ndi sedimentary media. Kupatula zofunikira zinazake, ma valve a diaphragm sayenera kugwiritsidwa ntchito pamapaipi a vacuum ndi zida za vacuum.