China Vacuum LOX Pipe Series
Kufotokozera Mwachidule:
- Mitundu yapamwamba kwambiri ya vacuum LOX yapaipi yopangidwira ntchito za cryogenic
- Imawonetsetsa kusamutsa bwino komanso kotetezeka kwa oxygen yamadzimadzi
- Wopangidwa ndi fakitale yotsogolera ku China
- Zosankha makonda zomwe zilipo kuti zikwaniritse zofunikira za polojekiti
- Kuchita kwapamwamba, kudalirika, ndi kulimba
Tsatanetsatane wa Zamalonda:
Mapangidwe Apamwamba ndi Zomangamanga:
China Vacuum LOX Pipe Series yathu idapangidwa mwaluso kuti ikwaniritse zofunikira za cryogenic application. Zotsatizanazi zimakhala ndi zida zapamwamba komanso njira zomangira zapamwamba, zomwe zimatsimikizira kulimba kwapadera komanso magwiridwe antchito pamikhalidwe yovuta kwambiri.
Kusamutsa Oxygen Wamadzimadzi Moyenera komanso Wotetezeka:
Gulu la vacuum LOX lapaipi lapangidwa kuti lithandizire kusamutsa koyenera komanso kotetezeka kwa okosijeni wamadzimadzi mkati mwa machitidwe a cryogenic. Kukonzekera kwake kwatsopano kumachepetsa chiopsezo cha kutayikira ndikuwonetsetsa kukhulupirika kwa njira yotumizira mpweya, zomwe zimathandiza kuti chitetezo chonse chikhale chotetezeka komanso chogwira ntchito.
Zokonda Zokonda:
Pozindikira zosowa zosiyanasiyana zama projekiti osiyanasiyana, China Vacuum LOX Pipe Series yathu imapereka zosankha zomwe mungasinthire kuti zigwirizane ndi zofunikira zenizeni. Kaya ndi kukula kwake, zakuthupi, kapena masinthidwe, titha kukonza mndandanda wa zitoliro kuti zigwirizane ndi zosowa za polojekiti, kupereka yankho losunthika pamapulogalamu osiyanasiyana.
Kudalirika ndi Kuchita:
Poyang'ana pazabwino komanso kudalirika, mndandanda wathu wapaipi wa vacuum LOX umapereka magwiridwe antchito, zomwe zimathandizira kuti magwiridwe antchito a cryogenic agwire ntchito bwino. Kupanga kwake kolimba komanso uinjiniya wolondola kumapangitsa kuti ikhale yankho lodalirika pamapulogalamu ovuta, kuwonetsetsa kuti ntchito yodalirika komanso yokhazikika kwanthawi yayitali.
Wopangidwa ndi Factory Yotsogola Yopanga Ku China:
Monga fakitale yodziwika bwino yopanga zinthu ku China, tadzipereka kutsata miyezo yapamwamba kwambiri yopangira zinthu zabwino kwambiri. China Vacuum LOX Pipe Series yathu ndi umboni wakudzipereka kwathu ku khalidwe, luso, komanso kukhutira kwamakasitomala, ndikupangitsa kukhala chisankho choyenera chofuna kugwiritsa ntchito cryogenic.
Pomaliza, gulu lathu la China Vacuum LOX Pipe Series limapereka yankho lapamwamba la machitidwe a cryogenic, opereka magwiridwe antchito apamwamba, odalirika, komanso chitetezo. Ndi zosankha zomwe mungasinthire komanso kuthandizidwa ndi fakitale yotsogola ku China, ndiye chisankho chabwino kwambiri chamitundu yambiri ya cryogenic.
Kanema
Vacuum Insulated Piping
Vacuum Insulated Pipe (VI Piping), yomwe ndi Vacuum Jacketed Pipe (VJ Piping), monga choloweza m'malo mwabwino chotsekereza mapaipi wamba. Poyerekeza ndi kutchinjiriza kwa mapaipi wamba, kutsika kwa kutentha kwa VIP kumangokhala nthawi 0.05 ~ 0.035 za kutsekereza mapaipi wamba. Sungani kwambiri mphamvu ndi mtengo kwa makasitomala.
Mndandanda wazinthu za Vacuum Jacketed Pipe, Vacuum Jacketed Hose, Vacuum Jacketed Valve, ndi Phase Separator mu HL Cryogenic Equipment Company, yomwe idadutsa njira zingapo zamankhwala okhwima kwambiri, imagwiritsidwa ntchito posamutsa mpweya wamadzimadzi, nayitrogeni yamadzimadzi, argon yamadzimadzi, madzi wa hydrogen, helium yamadzi, LEG ndi LNG, ndipo zinthu izi zimagwiritsidwa ntchito pazida za cryogenic (mwachitsanzo, akasinja a cryogenic, dewars ndi coldboxes etc.) m'mafakitale olekanitsa mpweya, mpweya, ndege, zamagetsi, superconductor, tchipisi, msonkhano wodzichitira, chakudya & chakumwa, mankhwala, chipatala, biobank, mphira, zinthu zatsopano kupanga mankhwala uinjiniya, chitsulo & zitsulo, ndi kafukufuku sayansi etc.
Mitundu itatu yolumikizira ya VI Piping
Mitundu itatu yolumikizira pano imagwira ntchito pazolumikizana pakati pa mapaipi a VI. Pamene VI Pipe ikugwirizanitsa ndi zipangizo, thanki yosungirako ndi zina zotero, cholumikizira cholumikizira chikhoza kusinthidwa malinga ndi zofuna za makasitomala.
Pofuna kukulitsa zosowa zosiyanasiyana za makasitomala, Vacuum Insulated Pipe yapanga mitundu itatu yolumikizira, yomwe ndi Vuta la Bayonet Connection Type with Clamp, Vacuum Bayonet Connection Type yokhala ndi Flanges ndi Bolts ndi Welded Connection Type. Iwo ali ndi ubwino wosiyana ndipo ndi oyenera ntchito zosiyanasiyana.
Kuchuluka kwa Ntchito
Vacuum Bayonet Connection Type yokhala ndi Clamps | Mtundu Wolumikizira wa Bayonet wokhala ndi Flanges ndi Bolts | Mtundu Wolumikizira Welded | |
Mtundu Wolumikizira | Ma clamps | Flanges ndi Bolts | Weld |
Mtundu wa Insulation pamagulu | Vuta | Vuta | Perlite kapena Vacuum |
Chithandizo cha Insulated Pamalo | No | No | Inde, perlite yodzaza kapena kutulutsa pampu kuchokera ku Manja Otsekeredwa pamalumikizidwe. |
Mwadzina Diameter of Inner Pipe | DN10(3/8")~DN25(1") | DN10(3/8")~DN80(3") | DN10(3/8")~DN500(20") |
Design Pressure | ≤8 bar | ≤16 bar | ≤64 bar |
Kuyika | Zosavuta | Zosavuta | Weld |
Kutentha kwa Design | -196 ℃~ 90 ℃ (LH2 & LHe: -270 ℃ ~ 90 ℃) | ||
Utali | 1 ~ 8.2 mita / ma PC | ||
Zakuthupi | 300 Series Stainless Steel | ||
Wapakati | LN2, LOX, LAr, LHe, LH2, LEG, LNG |
Kuchuluka kwa Zinthu Zogulitsa
Zogulitsa | Kufotokozera | Kulumikizana kwa Bayonet ndi Vacuum ndi Clamp | Kulumikizana kwa Bayonet ndi Vacuum ndi Flanges ndi Bolts | Weld Insulated Connection |
Vacuum Insulated Pipe | DN8 | INDE | INDE | INDE |
Chithunzi cha DN15 | INDE | INDE | INDE | |
DN20 | INDE | INDE | INDE | |
DN25 | INDE | INDE | INDE | |
DN32 | / | INDE | INDE | |
Chithunzi cha DN40 | / | INDE | INDE | |
Chithunzi cha DN50 | / | INDE | INDE | |
DN65 | / | INDE | INDE | |
DN80 | / | INDE | INDE | |
Chithunzi cha DN100 | / | / | INDE | |
Chithunzi cha DN125 | / | / | INDE | |
Chithunzi cha DN150 | / | / | INDE | |
Chithunzi cha DN200 | / | / | INDE | |
Chithunzi cha DN250 | / | / | INDE | |
DN300 | / | / | INDE | |
DN400 | / | / | INDE | |
DN500 | / | / | INDE |
Makhalidwe Aukadaulo
Compensator Design Pressure | ≥4.0MPa |
Kutentha kwa Design | -196C ~ 90 ℃ (LH2& LHe: -270~90℃) |
Ambient Kutentha | -50 ~ 90 ℃ |
Mlingo wa Vacuum Leakage Rate | ≤1*10-10Pa*m3/S |
Mulingo wa Vacuum Pambuyo pa Guarantee | ≤0.1 Pa |
Insulated Njira | High Vacuum Multi-Layer Insulation. |
Adsorbent ndi Getter | Inde |
NDI | 100% Mayeso a Radiographic |
Kupanikizika Kwambiri | 1.15 Times Design Pressure |
Wapakati | LO2, LN2, LAr, LH2, LHe, LEG, LNG |
Dynamic ndi Static Vacuum Insulated Piping System
Vacuum Insulated (VI) Piping System ikhoza kugawidwa mu Dynamic ndi Static VI Piping System.
lThe Static VI Piping imatsirizidwa kwathunthu mufakitale yopanga.
lThe Dynamic VI Piping imaperekedwa kuti ikhale yosasunthika kwambiri ndi kupopera kosalekeza kwa pampu ya vacuum pamalopo, ndipo zina zonse zochitira msonkhano ndi kukonza zidakali mufakitale yopangira.
Dynamic Vacuum Insulated Piping System | Static Vacuum Insulated Piping System | |
Mawu Oyamba | Digiri ya vacuum ya vacuum interlayer imayang'aniridwa mosalekeza, ndipo pampu ya vacuum imayendetsedwa yokha kuti itseguke ndi kutseka, kuti zitsimikizire kukhazikika komanso kuchita bwino kwa digiri ya vacuum. | Ma VJP amamaliza ntchito yotchinjiriza vacuum pamalo opangira. |
Ubwino wake | Kusungidwa kwa vacuum kumakhala kokhazikika, makamaka kuthetsa kukonza vacuum m'tsogolomu. | Ndalama zambiri zandalama komanso kuyika kosavuta patsamba |
Mtundu Wolumikizira wa Bayonet wokhala ndi Ma Clamp | Zothandiza | Zothandiza |
Mtundu Wolumikizira wa Bayonet wokhala ndi Flanges ndi Bolts | Zothandiza | Zothandiza |
Mtundu Wolumikizira Welded | Zothandiza | Zothandiza |
Dongosolo la Mapaipi Otsekera Amphamvu: Amakhala ndi Mapaipi Osungunula, Mapaipi a Jumper ndi Pump System (kuphatikiza mapampu a vacuum, ma valve solenoid ndi geji za vacuum).
Mafotokozedwe ndi Model
HL-PX-X-000-00-X
Mtundu
HL Cryogenic Equipment
Kufotokozera
PD: Dynamic VI Pipe
PS: Static VI Pipe
Mtundu Wolumikizira
W: Mtundu Wowotchedwa
B: Vacuum Bayonet Type yokhala ndi Ma Clamp
F: Mtundu wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts
Mwadzina Diameter of Inner Pipe
010:DN10
…
080:DN80
…
500: DN500
Design Pressure
08:8pa
16:16 gawo
25:25pa
32:32 gawo
40:40 gawo
Zinthu za Chitoliro Chamkati
A: SS304
Chithunzi cha SS304L
C: SS316
Chithunzi cha SS316L
E: Zina
Static Vacuum Insulated Piping System
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Zithunzi za HLPSB01008X | Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Ma Clamp a Static Vacuum Insulated Piping System | DN10, 3/8" | 8 bwalo
| 300 Series Stainless Steel | ASME B31.3 | X: Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
Zithunzi za HLPSB01508X | DN15, 1/2" | |||||
Zithunzi za HLPSB02008X | DN20, 3/4" | |||||
Zithunzi za HLPSB02508X | DN25, 1" |
Diameter Yodziwikiratu ya Chitoliro Chamkati:Analimbikitsa ≤ DN25 kapena 1". Kapena sankhani Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts (kuchokera ku DN10, 3/8" mpaka DN80, 3"), Welded Connection Type VIP (kuchokera ku DN10, 3/8" mpaka DN500, 20" )
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Design Pressure: Akulimbikitsidwa ≤ 8 bar. Kapena sankhani Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts (≤16 bar), Mtundu Wolumikizira Welded (≤64 bar)
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Zithunzi za HLPSF01000x pa | Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts for Static Vacuum Insulated Piping System | DN10, 3/8" | 8-16 gawo | 300 Series Stainless Steel | ASME B31.3 | 00: Design Pressure. 08 ndi 8bar, 16 ndi 16bar.
X: Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
Zithunzi za HLPSF01500x pa | DN15, 1/2" | |||||
Zithunzi za HLPSF02000x pa | DN20, 3/4" | |||||
Zithunzi za HLPSF02500x pa | DN25, 1" | |||||
Zithunzi za HLPSF03200x pa | DN32, 1-1/4" | |||||
Zithunzi za HLPSF04000x pa | DN40, 1-1/2" | |||||
Zithunzi za HLPSF05000x pa | DN50, 2" | |||||
Zithunzi za HLPSF06500x pa | DN65, 2-1/2" | |||||
Zithunzi za HLPSF08000x pa | DN80, 3" |
Diameter Yodziwikiratu ya Chitoliro Chamkati:Analimbikitsa ≤ DN80 kapena 3". Kapena kusankha Welded Connection Type (kuchokera ku DN10, 3/8" mpaka DN500, 20"), Vumbulutsani Bayonet Connection Type with Clamps (kuchokera DN10, 3/8" mpaka DN25, 1").
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Design Pressure: Akulimbikitsidwa ≤ 16 bar. Kapena sankhani Mtundu Wolumikizira Welded (≤64 bar).
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Zithunzi za HLPSW01000x pa | Mtundu Wolumikizira Wowotcherera wa Static Vacuum Insulated Piping System | DN10, 3/8" | 8-64 gawo | 300 Series Stainless Steel | ASME B31.3 | 00: Design Pressure 08 ndi 8bar, 16 ndi 16bar, ndi 25, 32, 40, 64.
X: Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
Zithunzi za HLPSW01500x pa | DN15, 1/2" | |||||
Zithunzi za HLPSW02000x pa | DN20, 3/4" | |||||
Zithunzi za HLPSW02500x pa | DN25, 1" | |||||
Zithunzi za HLPSW03200x pa | DN32, 1-1/4" | |||||
Zithunzi za HLPSW04000x pa | DN40, 1-1/2" | |||||
Zithunzi za HLPSW05000x pa | DN50, 2" | |||||
Zithunzi za HLPSW06500x pa | DN65, 2-1/2" | |||||
Zithunzi za HLPSW08000x pa | DN80, 3" | |||||
HChithunzi cha LPSW10000x pa | DN100, 4" | |||||
HChithunzi cha LPSW12500x pa | DN125, 5" | |||||
HChithunzi cha LPSW15000x pa | DN150, 6" | |||||
HChithunzi cha LPSW20000x pa | DN200, 8" | |||||
HChithunzi cha LPSW25000x pa | DN250, 10" | |||||
HChithunzi cha LPSW30000x pa | DN300, 12" | |||||
HChithunzi cha LPSW35000x pa | DN350, 14" | |||||
HChithunzi cha LPSW40000x pa | DN400, 16" | |||||
HChithunzi cha LPSW45000x pa | DN450, 18" | |||||
HChithunzi cha LPSW50000x pa | DN500, 20" |
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Dynamic Vacuum Insulated Piping System
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Mtengo wa HLPDB01008X | Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Ma Clamp a Static Vacuum Insulated Piping System | DN10, 3/8" | 8 bwalo | 300 Series Stainless Steel | ASME B31.3 | X:Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
HLPDB01508X | DN15, 1/2" | |||||
HLPDB02008X | DN20, 3/4" | |||||
HLPDB02508X | DN25, 1" |
Diameter Yodziwikiratu ya Chitoliro Chamkati:Analimbikitsa ≤ DN25 kapena 1". Kapena sankhani Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts (kuchokera ku DN10, 3/8" mpaka DN80, 3"), Welded Connection Type VIP (kuchokera ku DN10, 3/8" mpaka DN500, 20" )
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Design Pressure: Akulimbikitsidwa ≤ 8 bar. Kapena sankhani Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts (≤16 bar), Mtundu Wolumikizira Welded (≤64 bar)
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Mphamvu Yamagetsi:Malowa akuyenera kupereka mphamvu ku mapampu a vacuum ndikudziwitsa a HL Cryogenic Equipment zambiri zamagetsi zakomweko (Voltage ndi Hertz)
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Mtengo wa HLPDF01000x pa | Mtundu Wolumikizira wa Vacuum Bayonet wokhala ndi Flanges ndi Bolts for Static Vacuum Insulated Piping System | DN10, 3/8" | 8-16 gawo | 300 Series Stainless Steel | ASME B31.3 | 00: Design Pressure. 08 ndi 8bar, 16 ndi 16bar.
X: Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
HLPDF01500x pa | DN15, 1/2" | |||||
HLPDF02000x pa | DN20, 3/4" | |||||
HLPDF02500x pa | DN25, 1" | |||||
HLPDF03200x pa | DN32, 1-1/4" | |||||
HLPDF04000x pa | DN40, 1-1/2" | |||||
HLPDF05000x pa | DN50, 2" | |||||
HLPDF06500x pa | DN65, 2-1/2" | |||||
HLPDF08000x pa | DN80, 3" |
Diameter Yodziwikiratu ya Chitoliro Chamkati:Analimbikitsa ≤ DN80 kapena 3". Kapena kusankha Welded Connection Type (kuchokera ku DN10, 3/8" mpaka DN500, 20"), Vumbulutsani Bayonet Connection Type with Clamps (kuchokera DN10, 3/8" mpaka DN25, 1").
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Design Pressure: Akulimbikitsidwa ≤ 16 bar. Kapena sankhani Mtundu Wolumikizira Welded (≤64 bar).
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Mphamvu Yamagetsi:Malowa akuyenera kupereka mphamvu ku mapampu a vacuum ndikudziwitsa a HL Cryogenic Equipment zambiri zamagetsi zakomweko (Voltage ndi Hertz)
Model | KulumikizanaMtundu | Mwadzina Diameter of Inner Pipe | Design Pressure | Zakuthupiwa Inner Pipe | Standard | Ndemanga |
Mtengo wa HLPDW01000x pa | Mtundu Wolumikizira Welded wa Dynamic Vacuum Insulated Piping System | DN10, 3/8" | 8-64 gawo | Chitsulo chosapanga dzimbiri 304, 304L, 316, 316L | ASME B31.3 | 00: Design Pressure 08 ndi 8bar, 16 ndi 16bar, ndi 25, 32, 40, 64. .
X: Zinthu za Chitoliro Chamkati. A ndi 304, B ndi 304L, C ndi 316, D ndi 316L, E ndi zina. |
Mtengo wa HLPDW01500x pa | DN15, 1/2" | |||||
Mtengo wa HLPDW02000x pa | DN20, 3/4" | |||||
Mtengo wa HLPDW02500x pa | DN25, 1" | |||||
HLPDW03200x pa | DN32, 1-1/4" | |||||
HLPDW04000x pa | DN40, 1-1/2" | |||||
HLPDW05000x pa | DN50, 2" | |||||
HLPDW06500x pa | DN65, 2-1/2" | |||||
HLPDW08000x pa | DN80, 3" | |||||
HLPDW10000x pa | DN100, 4" | |||||
HChithunzi cha LPDW12500x pa | DN125, 5" | |||||
HChithunzi cha LPDW15000x pa | DN150, 6" | |||||
HLPDW20000x pa | DN200, 8" | |||||
HLPDW25000x pa | DN250, 10" | |||||
HLPDW30000x pa | DN300, 12" | |||||
HLPDW35000x pa | DN350, 14" | |||||
HLPDW40000x pa | DN400, 16" | |||||
HChithunzi cha LPDW45000x pa | DN450, 18" | |||||
HLPDW50000x pa | DN500, 20" |
Dzina Lodziwikiratu la Chitoliro Chakunja:Yovomerezedwa ndi Enterprise Standard ya HL Cryogenic Equipment. Komanso akhoza kupangidwa malinga ndi lamulo la kasitomala.
Zida za Outer Pipe: Popanda chofunikira chapadera, zinthu za chitoliro chamkati ndi chitoliro chakunja zidzasankhidwa chimodzimodzi.
Mphamvu Yamagetsi:Malowa akuyenera kupereka mphamvu ku mapampu a vacuum ndikudziwitsa a HL Cryogenic Equipment zambiri zamagetsi zakomweko (Voltage ndi Hertz)