{"id":2049,"count":10,"description":"\r\n\r\n\r\n\r\nOBTER O PRE\u00c7O DA V\u00c1LVULA DE GLOBO<\/strong><\/strong><\/a>\r\n\r\n\r\n\r\n\r\n

O que \u00e9 uma v\u00e1lvula de globo?<\/h2>\r\n\r\n\r\n\r\n\r\nAs v\u00e1lvulas de globo, assim chamadas devido \u00e0 sua forma exterior, s\u00e3o amplamente utilizadas em tubagens de instala\u00e7\u00f5es. S\u00e3o adequadas para o funcionamento manual e autom\u00e1tico. Ao contr\u00e1rio da v\u00e1lvula de gaveta, a v\u00e1lvula de globo pode ser utilizada para regular o caudal ou as press\u00f5es, bem como para cortar completamente o caudal. Por vezes, tamb\u00e9m pode ser utilizada como v\u00e1lvula de descompress\u00e3o ou como v\u00e1lvula de reten\u00e7\u00e3o. Em compara\u00e7\u00e3o com uma v\u00e1lvula de gaveta ou uma v\u00e1lvula de esfera, a v\u00e1lvula de globo tem uma perda de press\u00e3o consideravelmente maior na posi\u00e7\u00e3o totalmente aberta. Isto deve-se ao facto de o fluxo de fluido mudar de dire\u00e7\u00e3o ao atravessar a v\u00e1lvula. O r\u00e1cio L\/D para este tipo de v\u00e1lvula \u00e9 de aproximadamente 340. As v\u00e1lvulas de globo s\u00e3o fabricadas em tamanhos at\u00e9 NPS 16. S\u00e3o geralmente accionadas por roda manual.\r\n\r\n\r\n\r\n\r\n

Como \u00e9 que as v\u00e1lvulas de globo funcionam?<\/h2>\r\n\r\n\r\n\r\n\r\nUma v\u00e1lvula de globo \u00e9 concebida principalmente para parar, iniciar e regular o fluxo. \u00c9 composta por um disco m\u00f3vel e um assento de anel estacion\u00e1rio num corpo geralmente esf\u00e9rico. A sede de uma v\u00e1lvula de globo encontra-se no meio e paralela \u00e0 tubagem, e a abertura na sede \u00e9 fechada com o disco. Quando o man\u00edpulo \u00e9 rodado, manualmente ou atrav\u00e9s de um atuador, um disco \u00e9 baixado ou levantado atrav\u00e9s da haste da v\u00e1lvula. Quando o disco est\u00e1 totalmente baixado, o fluxo de fluido \u00e9 interrompido. Quando o disco est\u00e1 totalmente levantado, o caudal de fluido est\u00e1 no seu m\u00e1ximo. Quando o disco \u00e9 elevado a um n\u00edvel inferior ao m\u00e1ximo, o caudal de fluido \u00e9 regulado proporcionalmente ao curso vertical do disco.\r\n\r\n\r\n\r\n\r\n
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Tipos de v\u00e1lvulas globo<\/h2>\r\n\r\n\r\n\r\n\r\nExistem tr\u00eas modelos principais de corpos para as v\u00e1lvulas de globo, nomeadamente... Padr\u00e3o Tee ou corpo em Z, Padr\u00e3o Angular e Padr\u00e3o Wye ou corpo em Y.\r\n\r\n\r\n\r\n\r\n

Padr\u00e3o em T V\u00e1lvula globo<\/h3>\r\n\r\n\r\n\r\n\r\nO modelo de v\u00e1lvula de globo em T \u00e9 o tipo de corpo mais comum, com um diafragma em forma de Z. A configura\u00e7\u00e3o horizontal da sede permite que a haste e o disco se desloquem perpendicularmente \u00e0 linha horizontal. Este modelo tem o menor coeficiente de caudal e uma maior perda de carga. S\u00e3o utilizadas em servi\u00e7os de estrangulamento severo, como em linhas de deriva\u00e7\u00e3o \u00e0 volta de uma v\u00e1lvula de controlo. As v\u00e1lvulas de globo em forma de T tamb\u00e9m podem ser utilizadas em aplica\u00e7\u00f5es em que a queda de press\u00e3o n\u00e3o \u00e9 uma preocupa\u00e7\u00e3o e \u00e9 necess\u00e1rio estrangulamento.\r\n\r\n\r\n\r\n\r\n

V\u00e1lvulas de globo de padr\u00e3o angular<\/h3>\r\n\r\n\r\n\r\n\r\nO desenho das v\u00e1lvulas de globo de padr\u00e3o angular \u00e9 uma modifica\u00e7\u00e3o da v\u00e1lvula de globo de padr\u00e3o T b\u00e1sico. As extremidades desta v\u00e1lvula de globo est\u00e3o num \u00e2ngulo de 90 graus e o fluxo de fluido ocorre com uma \u00fanica volta de 90 graus. T\u00eam um coeficiente de caudal ligeiramente inferior ao das v\u00e1lvulas de globo em forma de estrela. S\u00e3o utilizadas em aplica\u00e7\u00f5es que t\u00eam per\u00edodos de caudal pulsante devido \u00e0 sua capacidade de lidar com o efeito de deslizamento deste tipo de caudal.\r\n\r\n\r\n\r\n\r\n

V\u00e1lvulas de globo com padr\u00e3o Wye<\/h3>\r\n\r\n\r\n\r\n\r\nA conce\u00e7\u00e3o das v\u00e1lvulas de globo de padr\u00e3o Wye \u00e9 uma alternativa \u00e0 elevada queda de press\u00e3o inerente \u00e0s v\u00e1lvulas de globo. A sede e a haste est\u00e3o inclinadas a cerca de 45 graus, o que proporciona um percurso de fluxo mais reto na abertura total e oferece a menor resist\u00eancia ao fluxo. Podem ser abertas durante longos per\u00edodos sem eros\u00e3o grave. S\u00e3o muito utilizadas para estrangulamento durante opera\u00e7\u00f5es sazonais ou de arranque. Podem ser atravessados com uma vareta para remover detritos quando utilizados em linhas de drenagem que est\u00e3o normalmente fechadas.\r\n\r\n\r\n\r\n\r\n

Constru\u00e7\u00e3o de v\u00e1lvulas de globo<\/h2>\r\n\r\n\r\n\r\n\r\nAs v\u00e1lvulas de globo t\u00eam normalmente hastes ascendentes e os tamanhos maiores t\u00eam uma constru\u00e7\u00e3o exterior de rosca e forquilha. Os componentes da v\u00e1lvula de globo s\u00e3o semelhantes aos da v\u00e1lvula de gaveta. Este tipo de v\u00e1lvula tem sedes num plano paralelo ou inclinado em rela\u00e7\u00e3o \u00e0 linha de fluxo.\r\n\r\n\r\n\r\n\r\n\r\nA manuten\u00e7\u00e3o das v\u00e1lvulas de globo \u00e9 relativamente f\u00e1cil, uma vez que os discos e as sedes s\u00e3o facilmente renovados ou substitu\u00eddos. Este facto torna as v\u00e1lvulas de globo particularmente adequadas para servi\u00e7os que requerem uma manuten\u00e7\u00e3o frequente das v\u00e1lvulas. Quando as v\u00e1lvulas s\u00e3o operadas manualmente, o curso mais curto do disco oferece vantagens na poupan\u00e7a de tempo do operador, especialmente se as v\u00e1lvulas forem ajustadas frequentemente.\r\n\r\n\r\n\r\n\r\n\r\nA principal varia\u00e7\u00e3o na conce\u00e7\u00e3o das v\u00e1lvulas de globo reside nos tipos de discos utilizados. Os discos do tipo obturador t\u00eam uma configura\u00e7\u00e3o longa e c\u00f3nica com uma superf\u00edcie de apoio larga. Este tipo de sede oferece a m\u00e1xima resist\u00eancia \u00e0 a\u00e7\u00e3o erosiva do fluxo de fluido. No disco de composi\u00e7\u00e3o, o disco tem uma face plana que \u00e9 pressionada contra a abertura da sede como uma tampa. Este tipo de disposi\u00e7\u00e3o da sede n\u00e3o \u00e9 t\u00e3o adequado para estrangulamento de press\u00e3o diferencial elevada.\r\n\r\n\r\n\r\n\r\n\r\nNas v\u00e1lvulas de globo de ferro fundido, os discos e os an\u00e9is da sede s\u00e3o normalmente feitos de bronze. Nas v\u00e1lvulas de globo em a\u00e7o para temperaturas at\u00e9 750\u00b0F (399\u00b0C), o revestimento \u00e9 geralmente feito de a\u00e7o inoxid\u00e1vel, o que proporciona resist\u00eancia \u00e0 gripagem e \u00e0 escoria\u00e7\u00e3o. As faces de contacto s\u00e3o normalmente tratadas termicamente para obter valores de dureza diferenciados. S\u00e3o tamb\u00e9m utilizados outros materiais de revestimento, incluindo ligas \u00e0 base de cobalto.\r\n\r\n\r\n\r\n\r\n\r\nA superf\u00edcie de assentamento \u00e9 rectificada para assegurar o contacto total da superf\u00edcie de apoio quando a v\u00e1lvula est\u00e1 fechada. Para classes de press\u00e3o mais baixas, o alinhamento \u00e9 mantido por uma longa porca de bloqueio do disco. Para press\u00f5es mais elevadas, as guias do disco s\u00e3o fundidas no corpo da v\u00e1lvula. O disco roda livremente na haste para evitar o engripamento da face do disco e do anel da sede. A haste suporta uma placa de impulso endurecida, eliminando o desgaste da haste e do disco no ponto de contacto.\r\n\r\n\r\n\r\n\r\n

Discos de v\u00e1lvula globo<\/h3>\r\n\r\n\r\n\r\n\r\nOs discos das v\u00e1lvulas de globo utilizam tr\u00eas modelos b\u00e1sicos de discos:\r\n\r\n\r\n\r\n\r\n

Disco de esferas (disco convencional)<\/h4>\r\n\r\n\r\n\r\n\r\nO disco de esferas \u00e9 adequado para baixas temperaturas e baixas press\u00f5es. Ideal para opera\u00e7\u00f5es de arranque e paragem. N\u00e3o \u00e9 adequado para a regula\u00e7\u00e3o do caudal.\r\n\r\n\r\n\r\n\r\n
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Disco de composi\u00e7\u00e3o \uff08Plugue girat\u00f3rio\uff09<\/h4>\r\n\r\n\r\n\r\n\r\nOs comp\u00f3sitos de discos de composi\u00e7\u00e3o s\u00e3o, por defini\u00e7\u00e3o, constitu\u00eddos por v\u00e1rios componentes. O disco \u00e9 quase sempre fabricado em metal, enquanto um anel n\u00e3o met\u00e1lico \u00e9 montado no disco para formar a \u00e1rea de assentamento. O material do anel n\u00e3o met\u00e1lico \u00e9 escolhido para ter boas caracter\u00edsticas de corros\u00e3o e eros\u00e3o e pode ser feito \u00e0 medida para garantir que \u00e9 adequado ao objetivo. Se o anel n\u00e3o met\u00e1lico for escolhido corretamente, dever\u00e1 permitir uma melhor veda\u00e7\u00e3o. Os discos compostos s\u00e3o frequentemente utilizados para aplica\u00e7\u00f5es em sistemas de vapor.\r\n\r\n\r\n\r\n\r\n
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Disco de encaixe<\/h4>\r\n\r\n\r\n\r\n\r\nOs discos de encaixe t\u00eam uma forma longa e c\u00f3nica. A forma do disco de encaixe torna-o muito mais adequado para estrangulamento do que os modelos de tipo composto e de disco esf\u00e9rico.\r\n\r\n\r\n\r\n\r\n
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Liga\u00e7\u00e3o do castelo da v\u00e1lvula de globo<\/h3>\r\n\r\n\r\n\r\n\r\nAs tampas s\u00e3o outros componentes importantes para as v\u00e1lvulas do tipo gaveta e globo. Ao desmontar o castelo, o pessoal de manuten\u00e7\u00e3o tem acesso aos mecanismos internos e pode substituir componentes como a sede, a haste, etc. (trim). A liga\u00e7\u00e3o castelo - corpo da v\u00e1lvula nas v\u00e1lvulas de globo apresenta-se numa variedade de modelos. Os casquilhos podem ser unidos ao corpo da v\u00e1lvula por meio de parafusos, flanges, soldadura ou por meio de um mecanismo de veda\u00e7\u00e3o por press\u00e3o; o casquilho pode ser parte integrante do corpo da v\u00e1lvula. Algumas das liga\u00e7\u00f5es entre o castelo e o corpo da v\u00e1lvula s\u00e3o descritas mais adiante.\r\n\r\n\r\n\r\n\r\n

Liga\u00e7\u00e3o de castelo aparafusada<\/h4>\r\n\r\n\r\n\r\n\r\nO castelo aparafusado (tamb\u00e9m designado por aparafusado) \u00e9 um dos modelos mais simples e menos dispendiosos. No entanto, a junta do castelo tem de se adaptar \u00e0s faces rotativas e o desaparafusamento frequente do castelo pode danificar as faces da junta. Al\u00e9m disso, o bin\u00e1rio necess\u00e1rio para apertar a junta do castelo torna-se muito elevado para as v\u00e1lvulas de maior dimens\u00e3o. Por este motivo, a utiliza\u00e7\u00e3o de capots aparafusados \u00e9 normalmente limitada a v\u00e1lvulas de dimens\u00e3o n\u00e3o superior a NPS 3.\r\n\r\n\r\n\r\n\r\n

Liga\u00e7\u00e3o de castelo soldado<\/h4>\r\n\r\n\r\n\r\n\r\nSe a tampa do compartimento do motor for feita de um material sold\u00e1vel, a liga\u00e7\u00e3o da tampa do compartimento do motor pode ser feita inteiramente por soldadura. Os castelo soldados n\u00e3o s\u00e3o apenas econ\u00f3micos, mas tamb\u00e9m mais fi\u00e1veis, independentemente do tamanho, da press\u00e3o de funcionamento e da temperatura. No entanto, uma grande desvantagem \u00e9 que o acesso aos componentes internos da v\u00e1lvula s\u00f3 pode ser obtido atrav\u00e9s da remo\u00e7\u00e3o da soldadura, o que pode provocar a deforma\u00e7\u00e3o do castelo. Por esta raz\u00e3o, os castelo soldados s\u00e3o normalmente utilizados apenas quando se espera que a v\u00e1lvula permane\u00e7a sem manuten\u00e7\u00e3o durante longos per\u00edodos, quando a v\u00e1lvula \u00e9 uma v\u00e1lvula descart\u00e1vel, ou quando a fiabilidade da veda\u00e7\u00e3o da junta do castelo ultrapassa a dificuldade de acesso aos componentes internos da v\u00e1lvula.\r\n\r\n\r\n\r\n\r\n

Anel de uni\u00e3o Liga\u00e7\u00e3o de castelo<\/h4>\r\n\r\n\r\n\r\n\r\nO castelo tamb\u00e9m pode ser fixado ao corpo da v\u00e1lvula por um anel de uni\u00e3o roscado separado. Esta constru\u00e7\u00e3o tem a vantagem de impedir qualquer movimento entre as faces da junta quando esta est\u00e1 a ser apertada. Assim, o desaparafusamento repetido do castelo n\u00e3o pode danificar facilmente as faces da junta. Tal como acontece com o castelo aparafusado, a utiliza\u00e7\u00e3o de casquilhos com um anel de uni\u00e3o aparafusado est\u00e1 limitada a tamanhos de v\u00e1lvula normalmente n\u00e3o superiores a DN 80 (NPS 3).\r\n\r\n\r\n\r\n\r\n

Selo de press\u00e3o Liga\u00e7\u00e3o da tampa<\/h4>\r\n\r\n\r\n\r\n\r\nO castelo com vedante de press\u00e3o supera a desvantagem do peso, permitindo que a press\u00e3o do fluido aperte a junta. A veda\u00e7\u00e3o do castelo torna-se, assim, mais apertada \u00e0 medida que a press\u00e3o do fluido aumenta. Este princ\u00edpio de constru\u00e7\u00e3o \u00e9 frequentemente preferido para v\u00e1lvulas de grandes dimens\u00f5es que operam a altas press\u00f5es e temperaturas.\r\n\r\n\r\n\r\n\r\n

V\u00e1lvula de globo para venda<\/h2>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo de flange\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/em><\/a><\/figcaption><\/figure>\r\n\r\n\r\n\r\n\r\nV\u00e1lvula globo de flange A v\u00e1lvula globo de flange ZECO pode ser dividida de acordo com a localiza\u00e7\u00e3o da rosca da haste. A rosca da haste da v\u00e1lvula globo de flange est\u00e1 fora do corpo, a vantagem \u00e9 que a eros\u00e3o da haste do meio, a lubrifica\u00e7\u00e3o f\u00e1cil tal estrutura \u00e9 comum.\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/a>\r\n\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo em a\u00e7o fundido\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/em><\/a><\/figcaption><\/figure>\r\n\r\n\r\n\r\n\r\nV\u00e1lvula globo de a\u00e7o fundido A v\u00e1lvula globo de a\u00e7o fundido da ZECO \u00e9 usada principalmente para ocasi\u00f5es de alta press\u00e3o e tamanho pequeno, a fun\u00e7\u00e3o \u00e9 conectar ou truncar o meio de tubula\u00e7\u00e3o.<\/a>\r\n\r\n\r\n\r\n<\/div>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo em a\u00e7o inoxid\u00e1vel\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/em><\/a><\/figcaption><\/figure>\r\n\r\n\r\n\r\n\r\nV\u00e1lvula de globo em a\u00e7o inoxid\u00e1vel A haste da v\u00e1lvula de globo em a\u00e7o inoxid\u00e1vel ZECO foi concebida com uma superf\u00edcie de assento traseiro c\u00f3nico da haste anti-expuls\u00e3o para permitir a reembalagem da v\u00e1lvula na posi\u00e7\u00e3o totalmente aberta.\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/a>\r\n\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo criog\u00e9nica\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/em><\/a><\/figcaption><\/figure>\r\n\r\n\r\n\r\n\r\nV\u00e1lvula de globo criog\u00e9nica Para manter a caixa de empanque afastada dos meios de baixa temperatura e evitar danos de contacto a longo prazo que afectem o desempenho da veda\u00e7\u00e3o, a haste da v\u00e1lvula de globo criog\u00e9nica ZECO \u00e9 alongada para fazer com que o empanque dure mais tempo.<\/a>\r\n\r\n\r\n\r\n<\/div>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"v\u00e1lvula
V\u00e1lvula de globo manual\/ OBTER PRE\u00c7O DA V\u00c1LVULA ><\/em><\/a><\/figcaption><\/figure>\r\n\r\n\r\n\r\n\r\nV\u00e1lvula de globo manual A v\u00e1lvula de globo manual ZECO utiliza uma estrutura de tipo de via. Para garantir a veda\u00e7\u00e3o do empanque da haste, utiliza-se um empanque de grafite flex\u00edvel.<\/a>\r\n\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo operada por engrenagem<\/figcaption><\/figure>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo Y<\/figcaption><\/figure>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n
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\"V\u00e1lvula
V\u00e1lvula de globo A105<\/figcaption><\/figure>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n<\/div>\r\n\r\n\r\n\r\n

Dire\u00e7\u00e3o do fluxo das v\u00e1lvulas de globo<\/h2>\r\n\r\n\r\n\r\n\r\nPara aplica\u00e7\u00f5es com temperaturas baixas, as v\u00e1lvulas de globo s\u00e3o normalmente instaladas de modo a que a press\u00e3o esteja sob o disco. Isto contribui para um funcionamento f\u00e1cil e ajuda a proteger o empanque.\r\n\r\n\r\n\r\n\r\n\r\nPara aplica\u00e7\u00f5es com servi\u00e7o de vapor a alta temperatura, as v\u00e1lvulas de globo s\u00e3o instaladas de modo a que a press\u00e3o esteja acima do disco. Caso contr\u00e1rio, a haste contrai-se com o arrefecimento e tende a levantar o disco da sede\r\n\r\n\r\n\r\n\r\n

Vantagens da v\u00e1lvula de globo<\/h2>\r\n\r\n\r\n\r\n
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    • Melhor fecho em compara\u00e7\u00e3o com a v\u00e1lvula de gaveta.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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        • Bom para opera\u00e7\u00f5es frequentes, pois n\u00e3o h\u00e1 receio de desgaste do assento e do disco<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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            • F\u00e1cil de reparar, uma vez que a sede e o disco podem ser acedidos a partir da parte superior da v\u00e1lvula<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                • Funcionamento r\u00e1pido em compara\u00e7\u00e3o com a v\u00e1lvula de gaveta devido ao comprimento do curso mais curto<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                    • Normalmente acionado por um atuador autom\u00e1tico<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n\r\n\r\n

                      Vantagens da v\u00e1lvula de globo<\/h2>\r\n\r\n\r\n\r\n
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                        • Elevada perda de carga devido a duas ou mais voltas em \u00e2ngulo reto do fluido que circula no corpo da v\u00e1lvula.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                            • Obstru\u00e7\u00f5es e descontinuidades no trajeto do fluxo que conduzem a uma elevada perda de carga.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                                • Numa linha de alta press\u00e3o de grandes dimens\u00f5es, as pulsa\u00e7\u00f5es e os impactos podem danificar as pe\u00e7as internas dos acess\u00f3rios.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                                    • Uma v\u00e1lvula de grandes dimens\u00f5es necessita de uma pot\u00eancia consider\u00e1vel para se abrir e produz ru\u00eddo durante o funcionamento.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                                        • \u00c9 mais pesada do que outras v\u00e1lvulas com a mesma press\u00e3o nominal.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
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                                            • Mais caro do que a v\u00e1lvula de gaveta.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n","link":"https:\/\/zecovalve.com\/pt\/categoria-do-produto\/globe-valve","name":"V\u00e1lvula de globo","slug":"globe-valve","taxonomy":"product_cat","parent":0,"meta":[],"yoast_head":"\nGlobe Valve - Types of Globe Valve | Globe Valve Manufacturer - ZECO<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/zecovalve.com\/pt\/categoria-do-produto\/globe-valve\" \/>\n<meta property=\"og:locale\" content=\"pt_PT\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Globe Valve - Types of Globe Valve | Globe Valve Manufacturer - ZECO\" \/>\n<meta property=\"og:description\" content=\"GET GLOBE VALVE PRICE What is a Globe Valve? Globe valves, so-called because of their outside shape, are widely used in plant piping. They are suitable for manual and automatic operation. Unlike the gate valve, the globe valve can be used for regulating flow or pressures as well as complete shutoff of flow. It may also be used sometimes as a pressure relief valve or as a check valve. Compared with a gate valve or ball valve, the globe valve has considerably higher pressure loss in the fully open position. This is because the flow of fluid changes direction as it goes through the valve. The L\/D ratio for this type of valve is approximately 340. Globe valves are manufactured in sizes up to NPS 16. They are generally hand wheel\u2013operated. How do Globe Valves Work? A globe valve is primarily designed to stop, start and regulate flow. It is comprised of a movable disk and a stationary ring seat in a generally spherical body. The seat of a globe valve is in the middle of and parallel to the pipe, and the opening in the seat is closed off with the disk. When the handle is turned, manually or through an actuator, a disc is lowered or raised by means of the valve stem. When the disc is fully lowered, the fluid flow is shut off. When the disc is fully raised, the fluid flow is at its maximum rate. When the disc is raised to less than the maximum level, the fluid flow is regulated in proportion to the vertical travel of the disc. Globe Valve Types There are three primary body designs for Globe valves, namely.. Tee Pattern or Z-body, Angle Pattern, and Wye Pattern or Y-body body. Tee Pattern Globe valve Tee Pattern Globe valve design is the most common body type, with a Z-shaped diaphragm. The horizontal setting of the seat allows the stem and disk to travel perpendicular to the horizontal line. This design has the lowest coefficient of flow and higher pressure drop. They are used in severe throttling services, such as in bypass lines around a control valve. Tee-pattern Globe valves may also be used in applications where pressure drop is not a concern and throttling is required. Angle Pattern Globe valves Angle Pattern Globe valves design is a modification of the basic Tee Pattern Globe valve. The ends of this Globe valve are at an angle of 90 degrees, and fluid flow occurs with a single 90 degrees turn. They have a slightly lower coefficient of flow than wye-pattern Globe valves. They are used in applications that have periods of pulsating flow because of their capability to handle the slugging effect of this type of flow. Wye Pattern Globe valves Wye Pattern Globe valves design is an alternative for the high pressure drop, inherent in Globe valves. The seat and stem are angled at approximately 45 degrees, which gives a straighter flowpath at full opening and offers the least resistance to flow. They can be cracked open for long periods without severe erosion. They are extensively used for throttling during seasonal or startup operations. They can be rod through to remove debris when used in drain lines that are normally closed. Construction of Globe valves Globe valves usually have rising stems, and the larger sizes are of the outside screw-and-yoke construction. The components of the Globe valve are similar to those of the gate valve. This type of valve has seats in a plane parallel or inclined to the line of flow. Maintenance of Globe valves is relatively easy, as the discs and seats are readily refurbished or replaced. This makes Globe valves particularly suitable for services that require frequent valve maintenance. Where valves are operated manually, the shorter disc travel offers advantages in saving operator time, especially if the valves are adjusted frequently. The principal variation in Globe-valve design is in the types of discs employed. Plug-type discs have a long, tapered configuration with a wide bearing surface. This type of seat provides maximum resistance to the erosive action of the fluid stream. In the composition disc, the disc has a flat face that is pressed against the seat opening like a cap. This type of seat arrangement is not as suitable for high differential pressure throttling. In cast-iron Globe valves, discs and seat rings are usually made of bronze. In steel-Globe valves for temperatures up to 750\u00b0F (399\u00b0C), the trim is generally made of stainless steel and so provides resistance to seizing and galling. The mating faces are normally heat-treated to obtain differential hardness values. Other trim materials, including cobalt-based alloys, are also used. The seating surface is ground to ensure full-bearing surface contact when the valve is closed. For lower pressure classes, alignment is maintained by a long disc locknut. For higher pressures, disc guides are cast into the valve body. The disc turns freely on the stem to prevent galling of the disc face and seat ring. The stem bears against a hardened thrust plate, eliminating the galling of the stem and disc at the point of contact. Globe Valve Discs Globe valve discs utilize three basic disc designs: Ball Disc (Conventional Disc) Ball disc is suitable for low temperatures and low pressures. Ideal for starting and stopping operations. Ill-suited for flow regulation. Composition Disc \uff08Swivel Plug\uff09 Composition disc composites by definition consist of several components. The disc is almost always manufactured from metal whilst a non-metallic ring is mounted onto the disc to form the seating area. The non-metallic ring material is chosen to have good corrosion and erosion characteristics and may be custom made to ensure it is fit for purpose. If the non-metallic ring is chosen correctly, it should allow for better sealing. Composite discs are often employed for steam system applications. Plug Disc Plug discs have a long and tapered shape. The shape of the plug disc makes it much more suitable for throttling than the composite and ball disc type designs. Globe Valve Bonnet Connection Bonnets are other important components for the gate and globe type valves. By dismantling the bonnet, the maintenance staff has access to the internal mechanisms and can replace components like the seat, the stem, etc (trim). The Bonnet \u2013 Valve Body connection on globe valves comes in a variety of designs. Bonnets may be joined to the valve body by means of bolts, flanges, welding, or by means of a pressure-seal mechanism; the bonnet may be an integral part of the valve body. A few of the bonnet\u2013valve body connections are detailed further. Bolted Bonnet Connection The bolted (also referred to as screwed-in) bonnet is one of the simplest and least expensive designs. However, the bonnet gasket must accommodate itself to rotating faces, and frequent unscrewing of the bonnet may damage the joint faces. Also, the torque required to tighten the bonnet joint becomes very large for the higher size valves. For this reason, the use of bolted bonnets is normally restricted to valve sizes not greater than NPS 3. Welded Bonnet Connection If the bonnet is made of a weldable material, the bonnet connection may be made entirely by welding. Welded bonnets are not only economical but also most reliable irrespective of size, operating pressure, and temperature. However, a major drawback is that access to the valve internals can be gained only by removing the weld which may cause the bonnet to distort. For this reason, welded bonnets are normally used only where the valve can be expected to remain maintenance-free for long periods, where the valve is a throw-away valve, or where the sealing reliability of the bonnet joint outweighs the difficulty of gaining access to the valve internals. Union Ring Bonnet Connection The bonnet may also be held to the valve body by a separate screwed union ring. This construction has the advantage of preventing any motion between the joint faces as the joint is being tightened. Repeatedly unscrewing the bonnet, therefore, cannot readily harm the joint faces. As with the screwed-in bonnet, the use of bonnets with a screwed union ring is restricted to valve sizes normally not greater than DN 80 (NPS 3). Pressure Seal Bonnet Connection The pressure-seal bonnet overcomes weight disadvantage by letting the fluid pressure tighten the joint. The bonnet seal, therefore, becomes tighter as the fluid pressure increases. This construction principle is frequently preferred for large valves operating at high pressures and temperatures. Globe Valve for Sale Flange Globe Valve\/ GET VALVE PRICE > Flange Globe Valve ZECO flange globe valve can be divided according to the location of the stem thread. Flange globe valve stem thread is outside of the body, the advantage is that stem erosion from the medium, easy lubrication such structure is common.\/ GET VALVE PRICE > Cast Steel Globe Valve\/ GET VALVE PRICE > Cast Steel Globe Valve ZECO cast steel globe valve is mainly used for occasions of high pressure and small size, function is to connect or truncate piping medium.\/ GET VALVE PRICE > Stainless Steel Globe Valve\/ GET VALVE PRICE > Stainless Steel Globe Valve The stem of ZECO stainless steel globe valve is designed with anti-blow-out stem conical backseat surface to permit repacking of the valve in the fully open position.\/ GET VALVE PRICE > Cryogenic Globe Valve\/ GET VALVE PRICE > Cryogenic Globe Valve In order to keep the stuffing box away from low-temperature media and prevent long-term contact damage affecting sealing performance, The stem of ZECO cryogenic globe valve is lengthened to make the packing last longer.\/ GET VALVE PRICE > Manual Globe Valve\/ GET VALVE PRICE > Manual Globe Valve ZECO manual globe valve uses way type structure. In order to make sure about the sealing at the stem packing, use flexible graphite packing.\/ GET VALVE PRICE > Gear Operated Globe Valve Y Globe Valve A105 Globe Valve Flow Direction of Globe\u00a0valves For applications with low temperatures, Globe valves are normally installed so that the pressure is under the disc. This contributes to an easy operation and helps protect the packing. For applications with high temperature steam service, Globe valves are installed so that the pressure is above the disk. Otherwise, the stem will contract upon cooling and tend to lift the disk off the seat Advantages of Globe Valve Better shut off as compared to gate valve. Good for frequent operation as no fear of wear of seat and disk Easy to repair, as the seat and disk can be accessed from the valve top Fast operation compares to gate valve due to shorter stroke length Usually operated by an automatic actuator Advantages of Globe Valve High head loss from two or more right-angle turns of flowing fluid within the valve body. Obstructions and discontinuities in the flow path leading to a high head loss. In a large high-pressure line, pulsations and impacts can damage internal trim parts. A large valve requires considerable power to open and create noise while in operation. It is heavier than other valves of the same pressure rating. 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