ʻOiainā pahupaʻi plastikManaʻo ʻia i kekahi manawa he huahana kūikawā-ʻo ka koho mua loa no ka poʻe e hana a hoʻolālā paha i nā huahana paipu plastik no nā ʻōnaehana ʻoihana a i ʻole nā ​​​​mea hoʻomaʻemaʻe ultra-he pōkole ke manaʻo nei ʻaʻole nui nā hoʻohana maʻamau i kēia mau kiwi. ʻO kaʻoiaʻiʻo, he nui ka hoʻohana ʻana o nā kiwi plastik i kēia lā, no ka mea, hoʻomau ka hoʻonui ʻana o nā ʻano mea, a ʻo nā mea hoʻolālā maikaʻi e pono ai i kēia mau mea ke manaʻo nei he nui nā ala e hoʻohana ai i kēia mau mea hana multifunctional.

NA WAIWAI O PLASTIK

ʻO nā mea maikaʻi o nā valve thermoplastic he ākea-ʻo ka corrosion, kemika a me ke kūpaʻa abrasion; pahee o loko; kaumaha māmā; maʻalahi o ka hoʻokomo; ka lōʻihi o ke ola; a haʻahaʻa ke kumu kūʻai o ke ola. Ua alakaʻi ʻia kēia mau mea maikaʻi i ka ʻae ʻia ʻana o nā valve plastic i nā ʻoihana ʻoihana a me nā noi ʻoihana e like me ka hāʻawi ʻana i ka wai, ka mālama ʻana i ka wai ʻino, ka metala a me ka hana kemika, nā meaʻai a me nā lāʻau lapaʻau, nā mea kanu mana, nā aila refineries a me nā valve moPlastic hiki ke hana ʻia mai nā ʻano mea like ʻole. i kekahi mau hoʻonohonoho. Hana ʻia nā kīwī thermoplastic maʻamau me ka polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), a me ka polyvinylidene fluoride (PVDF). Hoʻohui pinepine ʻia nā kiwi PVC a me CPVC i nā ʻōnaehana paipu e nā ʻāpana kumu hoʻoheheʻe hoʻoheheʻe ʻana, a i ʻole nā ​​ʻaoʻao wili a me nā flanged; akā, koi ʻo PP a me PVDF i ka hoʻohui ʻana i nā ʻāpana ʻōnaehana paipu, ma o nā ʻenehana wela, butt- a i ʻole electro-fusion.

ʻOi aku ka maikaʻi o nā valve Thermoplastic i nā kaiapuni corrosive, akā ua like lākou me ka pono i ka lawelawe wai maʻamau no ka mea ʻaʻole lākou ke alakaʻi 1, pale i ka dezincification a ʻaʻole e pala. Pono e ho'āʻo a hōʻoia ʻia nā ʻōnaehana paipu PVC a me CPVC i ka NSF [National Sanitation Foundation] maʻamau 61 no nā hopena olakino, me ke koi haʻahaʻa haʻahaʻa no Annex G. ʻO ke koho ʻana i nā mea kūpono no nā wai corrosive hiki ke mālama ʻia ma ke kūkākūkā ʻana i ke kūpaʻa kemika o ka mea hana. alakaʻi a hoʻomaopopo i ka hopena o ka wela ma luna o ka ikaika o nā mea plastik.

ʻOiai ʻo ka polypropylene ka hapalua o ka ikaika o PVC a me CPVC, loaʻa iā ia ke kūpaʻa kemika nui loa no ka mea ʻaʻohe mea hoʻohenehene i ʻike ʻia. Hana maikaʻi ʻo PP i nā ʻakika acetic concentrated a me nā hydroxides, a ua kūpono hoʻi ia no nā hoʻonā haʻahaʻa o ka hapa nui o nā waikawa, alkalis, paʻakai a me nā kinikona he nui.

Loaʻa ʻia ka PP ma ke ʻano he pigmented a i ʻole nā ​​​​mea kūlohelohe (maoli). Hoʻohaʻahaʻa nui ʻia ka PP kūlohelohe e ka radiation ultraviolet (UV), akā ua hoʻopaʻa pono ʻia nā pūhui i ʻoi aku ma mua o 2.5% carbon black pigmentation.

Hoʻohana ʻia nā ʻōnaehana paipu PVDF i nā ʻano ʻoihana like ʻole mai ka lāʻau lapaʻau a hiki i ka mining ma muli o ka ikaika o PVDF, ka mahana hana a me ke kūpaʻa kemika i nā paʻakai, nā waikawa ikaika, nā kumu dilute a me nā mea hoʻoheheʻe he nui. ʻAʻole like me PP, ʻaʻole hoʻohaʻahaʻa ʻia ka PVDF e ka lā; akā naʻe, akaka ka plastic i ka lā a hiki ke hōʻike i ka wai i ka pāhawewe UV. ʻOiai he mea maikaʻi loa ka hoʻokumu ʻia ʻana o ka PVDF no ka maʻemaʻe kiʻekiʻe, ka hoʻohana ʻana i loko, me ka hoʻohui ʻana i kahi puaʻa e like me ka ʻulaʻula meaʻai e ʻae i ka ʻike ʻana i ka lā me ka ʻole o ka hopena maikaʻi ʻole i ke ʻano wai.

Loaʻa i nā ʻōnaehana plastik nā pilikia hoʻolālā, e like me ka naʻau i ka wela a me ka hoʻonui ʻana a me ka hoʻohaʻahaʻa ʻana, akā hiki i nā ʻenekinia ke hana a hoʻolālā i nā ʻōnaehana paipu maikaʻi loa no nā kaiapuni maʻamau a me ka corrosive. ʻO ka manaʻo nui o ka hoʻolālā ʻana, ʻoi aku ka nui o ka coefficient o ka hoʻonui wela no nā plastics ma mua o ka metala - ʻo ka thermoplastic he ʻelima a ʻeono manawa o ke kila, no ka laʻana.

I ka hoʻolālā ʻana i nā ʻōnaehana paipu a me ka noʻonoʻo ʻana i ka hopena i ka hoʻokomo ʻana i ka valve a me nā kākoʻo valve, kahi mea nui e noʻonoʻo ai i ka thermoplastics ka elongation thermal. Hiki ke hōʻemi a hoʻopau ʻia nā koʻikoʻi a me nā ikaika i loaʻa mai ka hoʻonui ʻana i ka wela a me ka hoʻopau ʻana ma o ka hāʻawi ʻana i ka maʻalahi i nā ʻōnaehana paipu ma o ka hoʻololi pinepine ʻana i ke kuhikuhi a i ʻole ka hoʻokomo ʻana i nā puka lou. Ma ka hāʻawi ʻana i kēia maʻalahi ma ka ʻōnaehana paipu, ʻaʻole koi ʻia ka valve plastic e komo i ka nui o ke kaumaha (Figure 1).

Ma muli o ka maʻalahi o ka thermoplastics i ka mahana, e emi ana ka helu kaomi o ka valve i ka piʻi ʻana o ka mahana. Loaʻa i nā mea plastik like ʻole ka deration me ka piʻi ʻana o ka mahana. ʻAʻole paha ʻo ka wela o ka wai wale nō ke kumu wela e hiki ke hoʻopilikia i ka helu kaomi ʻana o nā kiwi palaki—ʻo ka wela o waho ke kiʻekiʻe e pono e lilo i ʻāpana o ka noʻonoʻo ʻana. I kekahi mau hihia, ʻaʻole i hoʻolālā ʻia ka wela o waho e hiki ke hoʻonui i ka sagging ma muli o ka nele o nā kākoʻo paipu. He 140°F ka mahana lawelawe o PVC; Loaʻa i ka CPVC ka lōʻihi o 220°F; Loaʻa iā PP ka kiʻekiʻe o 180 ° F; a hiki i nā kiwi PVDF ke mālama i ke kaomi a hiki i 280°F (Figure 2).

Ma ka ʻaoʻao ʻē aʻe o ka pālākiō wela, ʻoi aku ka maikaʻi o ka hapa nui o nā ʻōnaehana paipu plastik i nā mahana ma lalo o ka hau. ʻOiaʻiʻo, piʻi ka ikaika tensile i ka paipu thermoplastic i ka emi ʻana o ka mahana. Eia nō naʻe, e emi ana ka pale ʻana o ka hapa nui o nā plastik i ka hāʻule ʻana o ka mahana, a ʻike ʻia ka palupalu i nā mea paipu i hoʻopilikia ʻia. ʻOiai ʻaʻole i hoʻopilikia ʻia nā kiwi a me nā ʻōnaehana paipu e pili ana, ʻaʻole pilikia i ka paʻi ʻana a i ʻole ke kuʻi ʻana o nā mea, a ʻaʻole i hāʻule ka paipu i ka wā e lawelawe ai, e hōʻemi ʻia nā hopena ʻino i ka paipu plastik.

NA ANO O NA WAIWAI THERMOPLASTIC

ʻO nā kinipōpō,nā pahu hopu,kiwi lelea loaʻa nā pahu diaphragm i kēlā me kēia o nā mea thermoplastic ʻokoʻa no ka papa kuhikuhi 80 puʻupuʻu puʻupuʻu paipu i loaʻa pū kekahi mau koho ʻoki a me nā lako. ʻO ka valve pōleʻa maʻamau ka mea maʻamau i ʻike ʻia he hoʻolālā uniona maoli e hoʻomaʻamaʻa i ka wehe ʻana i ke kino valve no ka mālama ʻana me ka ʻole o ka hoʻopili ʻana i ka paipu. Loaʻa nā kiwi hoʻopaʻa Thermoplastic e like me ka nānā ʻana i ka pōleʻa, nā loiloi koʻi, nā y-checks a me nā māka cone. Hoʻopaʻa maʻalahi nā kiwi kīpē me nā ʻāpana metala no ka mea ua kūlike lākou i nā puka pōʻai, nā pōʻai pōʻai a me nā ana holoʻokoʻa o ANSI Class 150. ʻO ke anawaena maʻemaʻe o loko o nā ʻāpana thermoplastic e hoʻohui wale i ka mana pololei o nā kiwi diaphragm.

Hana ʻia nā ʻāpana kinipōpō ma PVC a me CPVC e kekahi mau hui US a me nā ʻāina ʻē i ka nui o 1/2 iniha a hiki i 6 iniha me ke kumu, nā kaula a i ʻole nā ​​loulou flanged. ʻO ka hoʻolālā uniona maoli o nā kīpē pōleʻa o kēia wā e loaʻa ana ʻelua mau nati e wili ana i ke kino, e hoʻopaʻa ana i nā sila elastomeric ma waena o ke kino a me nā mea hoʻopili hope. Ua mālama kekahi po'e mea hana i ka lō'ihi o ka ho'opa'a 'ana i ka valve pōle'ele a me nā kaula nut no nā makahiki he 'umi e hiki ai ke ho'ololi ma'alahi i nā valve kahiko me ka ho'ololi 'ole i ka paipu pili.

Pono e hōʻoia i ka NSF-61G nā pahu pahu me ka ethylene propylene diene monomer (EPDM) e hoʻohana i ka wai inu. Hiki ke hoʻohana ʻia nā sila elastomeric Fluorocarbon (FKM) ma ke ʻano he mea ʻē aʻe no nā ʻōnaehana kahi e hopohopo ai ka hoʻohālikelike kemika. Hiki ke hoʻohana ʻia ka FKM i ka hapa nui o nā noi e pili ana i nā ʻakika mineral, koe wale ka hydrogen chloride, nā paʻakai paʻakai, chlorinated hydrocarbons a me nā aila ʻaila.

Kiʻi 3. ʻO ka pahu pōpō flanged i hoʻopili ʻia i kahi pahu. hiki i ka lawelawe ke like me 250 psi ma 73°F. 'Oi aku ka nui o na kiwi poepoe, 2-1/2 'īniha a hiki i 6 'īniha, e loa'a i ka helu kaomi ha'aha'a o 150 psi ma 73°F. Hoʻohana maʻamau ʻia i ka lawe ʻana i nā kemika, nā kiwi pōpō PP a me PVDF (Nā Kiʻi 3 a me 4), loaʻa i nā nui 1/2-iniha a hiki i 4 iniha me ke kumu, kaula a i ʻole nā ​​hopena flanged-hopena e helu pinepine ʻia i kahi lawelawe wai hoʻohālua ʻole. 150 psi i ka wela ambient.

Ke hilinaʻi nei nā kiwi pōleʻa Thermoplastic i ka pōpō me ka ʻumekaumaha kikoʻī ʻoi aku ka liʻiliʻi o ka wai, no laila inā e nalowale ke kaomi ma ka ʻaoʻao i uka, e hoʻi hou ka pōleʻa i ka ʻili o ka sila. Hiki ke hoʻohana ʻia kēia mau valves i ka lawelawe like me nā valve ball plastic like no ka mea ʻaʻole lākou e hoʻolauna i nā mea hou i ka ʻōnaehana. Hiki i nā ʻano ʻano ʻokoʻa ʻē aʻe ke hoʻokomo i nā pūnāwai metala ʻaʻole hiki ke hoʻopaʻa ʻia ma nā wahi ʻino.

Kiʻi 5. ʻO ka valve butterfly me ka laina elastomeric. ʻO nā mea hana o nā kiwi lele plastik e lawe i nā ala like ʻole i ke kūkulu ʻana a me ka hoʻopaʻa ʻana i nā papa. Hoʻohana kekahi i kahi liner elastomeric (Figure 5) a i ʻole O-ring, aʻo kekahi e hoʻohana i kahi diski i uhi ʻia e ka elastomeric. Hana kekahi i ke kino mai loko mai o ka mea hoʻokahi, akā ʻo nā ʻāpana i hoʻomaloʻo ʻia e lilo i mea ʻōnaehana, ʻo ia hoʻi he polypropylene butterfly valve body hiki ke loaʻa kahi liner EPDM a me PVC disc a i ʻole kekahi mau hoʻonohonoho ʻē aʻe me nā thermoplastics maʻamau a me nā sila elastomeric.

He mea maʻalahi ka hoʻokomo ʻana i ka valve butterfly no ka mea ua hana ʻia kēia mau kiwi i ke ʻano wafer me nā sila elastomeric i hoʻolālā ʻia i loko o ke kino. ʻAʻole pono lākou e hoʻohui i kahi gasket. E hoʻonoho ʻia ma waena o ʻelua mau lehelehe male, pono e mālama ʻia me ka mālama ʻana i ka bolting down of a plastic butterfly valve ma ka piʻi ʻana i ka torque bolt i ʻōlelo ʻia i ʻekolu mau pae. Hana ʻia kēia i mea e hoʻopaʻa pono ai i ka sila ma luna o ka ʻili a ʻaʻole i kau ʻia ke koʻikoʻi mechanical uneven ma ka valve.

Kiʻi 6. E ʻike nā poʻe loea valve metal i nā hana kiʻekiʻe o nā kiwi diaphragm plastic me ka huila a me nā hōʻailona kūlana i maʻa (Figure 6); akā naʻe, hiki i ka pahu diaphragm plastic ke hoʻokomo i kekahi mau pōmaikaʻi ʻokoʻa e like me nā paia o loko o ke kino thermoplastic. E like me ka pahu pōpō plastik, hiki i nā mea hoʻohana o kēia mau valve ke koho e hoʻokomo i ka hoʻolālā uniona maoli, hiki ke hoʻohana pono no ka hana mālama ʻana i ka valve. A i ʻole, hiki i kahi mea hoʻohana ke koho i nā pili flanged. Ma muli o nā koho āpau o ke kino a me nā mea diaphragm, hiki ke hoʻohana ʻia kēia valve i nā ʻano hana kemika.

E like me kēlā me kēia valve, ʻo ke kī i ka hoʻokō ʻana i nā valve plastic ke hoʻoholo nei i nā koi hana e like me ka pneumatic versus electric a me DC versus AC mana. Akā me ka plastic, pono e hoʻomaopopo ka mea hoʻolālā a me ka mea hoʻohana i ke ʻano o ke kaiapuni e hoʻopuni ai i ka mea hana. E like me ka mea i haʻi mua ʻia, he koho maikaʻi loa nā valve plastic no nā kūlana corrosive, e komo pū ana me nā wahi corrosive waho. Ma muli o kēia, he mea koʻikoʻi ka noʻonoʻo ʻana i ka mea hale o nā actuators no nā valve plastic. Loaʻa i nā mea hana valve plastik nā koho e hoʻokō i nā pono o kēia mau wahi corrosive ma ke ʻano o nā mea hana i uhi ʻia i ka plastik a i ʻole nā ​​​​hihia metala epoxy-coated.

E like me ka hōʻike ʻana o kēia ʻatikala, hāʻawi nā pahu plastik i kēia lā i nā ʻano koho āpau no nā noi a me nā kūlana hou.