![\"\"](\"https:\/\/zecovalve.com\/wp-content\/uploads\/2022\/01\/20220105083122-61d5575ae65f4.jpg\")
<\/figure>\n<\/div>\n\n\nWie funktioniert ein Membranventil?<\/h2>\n\n\n\n
Die Antriebskraft f\u00fcr ein Membranventil kann aus verschiedenen Quellen stammen. Ein pneumatisches Membranventil wird zum \u00d6ffnen oder Schlie\u00dfen mit Luftdruck betrieben. Manchmal wird ein Magnet \u2013 ein drahtumwickeltes Metallbauteil, das bei Vorhandensein von Elektrizit\u00e4t ein Magnetfeld erzeugen kann \u2013 zum Bet\u00e4tigen des Ventils verwendet. In anderen F\u00e4llen kann es manuell bedient werden. Dar\u00fcber hinaus wird h\u00e4ufig auch Hydraulikdruck verwendet.<\/p>\n\n\n\n
Arten von Membranventilen<\/h2>\n\n\n\n- Wehrmembranventile<\/strong>
- Das Membranventil vom Wehrtyp ist eine der g\u00e4ngigsten Konstruktionen und wird in Abbildung 2 oben gezeigt. Die Konstruktion mit erh\u00f6hter Lippe\/Sattel eignet sich am besten f\u00fcr die Regelung kleiner Durchflussmengen und ist dank der Haube \u00fcber der Membran und dem Antrieb dicht. Diese Konstruktion ist optimal f\u00fcr gef\u00e4hrliche oder \u00e4tzende Fl\u00fcssigkeiten und Gase, da jeder Membranfehler durch diese Haube einged\u00e4mmt wird. Au\u00dferdem ist dieses Ventil durch den geneigten K\u00f6rper von Natur aus selbstentleerend, aber diese Entleerung kann in beide Ventilrichtungen erfolgen, was f\u00fcr manche Anwendungen nicht optimal sein kann. Das Wehrventil wird meist f\u00fcr saubere, homogene Fl\u00fcssigkeiten spezifiziert, da sich auf beiden Seiten des Sattels viskose Schl\u00e4mme und Sedimente ansammeln k\u00f6nnen. Man findet sie am h\u00e4ufigsten in Prozessen wie Lebensmittel-\/Chemie-, Gasproduktions-, Korrosions- und Wasseranwendungen.<\/li><\/ul><\/li>
- Membranventile mit geradem Durchgang<\/strong>
- Das Durchgangsmembranventil ist strukturell \u00e4hnlich wie Wehrventile, besitzt jedoch nicht den charakteristischen Sattel, sondern einen vollst\u00e4ndig geraden Weg. Ihre Membranen sind in der Regel flexibler und erm\u00f6glichen gr\u00f6\u00dfere Bewegungsdistanzen, da sie den Boden des Ventils ber\u00fchren m\u00fcssen. Diese Ventile m\u00fcssen h\u00e4ufig gewartet\/ausgetauscht werden, da ihre Lebensdauer aufgrund ihrer flexibleren Membranen in der Regel k\u00fcrzer ist als bei Wehrventilen. Durchgangsmembranventile werden f\u00fcr Schl\u00e4mme, viskose Fl\u00fcssigkeiten und andere Anwendungen verwendet, bei denen Verstopfungen reduziert werden m\u00fcssen. Sie sind auch f\u00fcr bidirektionale Str\u00f6mungsregime n\u00fctzlich, da kein Sattel vorhanden ist, der einen schnellen Wechsel von Einlass zu Auslass behindert.<\/li><\/ul><\/li><\/ul>\n\n\n\n
Vorteile von Membranventilen?<\/h2>\n\n\n\n- Membranventile k\u00f6nnen auch f\u00fcr Drosselzwecke verwendet werden.<\/li>
- Aufgrund der gro\u00dfen Absperrfl\u00e4che entlang des Sitzes weist es im Wesentlichen die Drosseleigenschaften eines schnell \u00f6ffnenden Ventils auf.<\/li>
- Zur Regelung kleiner Durchfl\u00fcsse steht ein Wehrmembranventil zur Verf\u00fcgung.<\/li>
- Membranventile eignen sich besonders f\u00fcr den Umgang mit korrosiven Fl\u00fcssigkeiten, faserigen Schl\u00e4mmen, radioaktiven Fl\u00fcssigkeiten oder anderen Fl\u00fcssigkeiten, die frei von Verunreinigungen bleiben m\u00fcssen.<\/li>
- Der Betriebsmechanismus eines Membranventils ist nicht dem Medium in der Rohrleitung ausgesetzt. Klebrige oder viskose Fl\u00fcssigkeiten k\u00f6nnen nicht in die Ventilhaube gelangen und den Betriebsmechanismus beeintr\u00e4chtigen.<\/li>
- Viele Fl\u00fcssigkeiten, die die Funktionsteile der meisten anderen Ventiltypen verstopfen, korrodieren oder verkleben w\u00fcrden, passieren ein Membranventil ohne Probleme. Umgekehrt d\u00fcrfen Schmiermittel f\u00fcr den Betriebsmechanismus die zu behandelnde Fl\u00fcssigkeit nicht verunreinigen.<\/li>
- Es m\u00fcssen keine Stopfbuchsen gewartet werden und es besteht keine Gefahr einer Undichtigkeit der Ventilspindel.<\/li><\/ul>\n\n\n\n\n
Verwandte Tags:<\/h2>\n\n\n\n\n\nZECO-Ventil<\/a>\n\n<\/div>\n\n\n\n\nUnterschied zwischen Absperrschieber und Absperrklappe<\/a>\n\n<\/div>\n\n\n\n\nWas sind Absperrventile?<\/a>\n\n<\/div>\n\n\n\n\nHersteller von manuell bet\u00e4tigten Absperrschiebern<\/a>\n\n<\/div>\n\n\n\n\nWas ist ein Absperrschieber?<\/a>\n\n<\/div>\n\n\n\n\nShanghai Druckminderventilfabrik<\/a>\n\n<\/div>\n\n\n\n\nWas sind automatische Regelventile?<\/a>\n\n<\/div>\n\n\n\n\nDurchgangsventil vs. Kugelhahn<\/a>\n\n<\/div>\n\n\n\n\n12-Zoll-Schieberventillieferant<\/a>\n\n<\/div>\n\n\n\n\nThermoplastische Materialien als Kugelhahnsitz und Absperrklappensitz<\/a>\n\n<\/div>","protected":false},"excerpt":{"rendered":"Membranventile sind in den meisten Situationen keine wichtige \u00dcberlegung. Aber wenn ein Ventil Ihre Leistung in nachgelagerten Prozessen verbessern kann, dann \u2026 Weiterlesen ...<\/a><\/p>","protected":false},"author":2,"featured_media":13348,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_generate-full-width-content":"","kt_blocks_editor_width":"","footnotes":""},"categories":[1],"tags":[2702,2704,2703,3205],"class_list":["post-3059","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-diaphragm-valve","tag-diaphragm-valve-diagram","tag-diaphragm-valve-function","tag-diaphragm-valve-manufacturers","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-50"],"featured_image_src_large":["https:\/\/zecovalve.com\/wp-content\/uploads\/2022\/01\/20220105083122-61d5575ae65f4.jpg",924,1004,false],"author_info":{"display_name":"Jerry","author_link":"https:\/\/zecovalve.com\/de\/author\/jerry"},"comment_info":0,"category_info":[{"term_id":1,"name":"Uncategorized","slug":"uncategorized","term_group":0,"term_taxonomy_id":1,"taxonomy":"category","description":"","parent":0,"count":452,"filter":"raw","cat_ID":1,"category_count":452,"category_description":"","cat_name":"Uncategorized","category_nicename":"uncategorized","category_parent":0}],"tag_info":[{"term_id":2702,"name":"Diaphragm Valve","slug":"diaphragm-valve","term_group":0,"term_taxonomy_id":2702,"taxonomy":"post_tag","description":"","parent":0,"count":3,"filter":"raw"},{"term_id":2704,"name":"diaphragm valve diagram","slug":"diaphragm-valve-diagram","term_group":0,"term_taxonomy_id":2704,"taxonomy":"post_tag","description":"","parent":0,"count":2,"filter":"raw"},{"term_id":2703,"name":"Diaphragm Valve Function","slug":"diaphragm-valve-function","term_group":0,"term_taxonomy_id":2703,"taxonomy":"post_tag","description":"\r\n\r\n\r\n\r\nGET DIAPHRAGM VALVE DIAGRAM INFORMATION<\/strong><\/a>\r\n\r\n\r\n\r\n\r\nWhat is a Diaphragm Valve?<\/h2>\r\n\r\n\r\n\r\n\r\nDiaphragm valves get their name from a flexible disc that comes into contact with a seat at the top of the valve body to form a seal. A diaphragm is a flexible, pressure-responsive element that transmits force to open, close, or control a valve. Diaphragm valves are related to pinch valves, but use an elastomeric diaphragm, instead of an elastomeric liner in the valve body, to separate the flow stream from the closure element.\r\n\r\n\r\n\r\n\r\n![\"\"](\"https:\/\/zecovalve.com\/wp-content\/uploads\/2022\/07\/20220708083634-62c7ec92aba44.jpg\")
<\/figure>\r\n\r\n\r\n\r\nHow do Diaphragm Valves Work?<\/h2>\r\n\r\n\r\n\r\n\r\nDiaphragm valves are simple in construction and operation. A valve actuator is in contact with the inner membrane (or \u201cdiaphragm\u201d) of the valve in its open position. When the user desires the valve to be shut, the actuator is pressed and\/or turned and the membrane is pushed into the edge of the solid damn, closing the valve. Certain diaphragm valves can also have half open\/restricted positions where the membrane is partially closed, allowing a throttled flow through the valve. In the next section, we will examine the broad categories of diaphragm valves and where they are most useful.\r\n\r\n\r\n\r\n\r\nTypes of Diaphragm Valves<\/h2>\r\n\r\n\r\n\r\nWeir-Type Diaphragm Valves<\/h3>\r\n\r\n\r\n\r\n\r\nThe weir-type diaphragm valve is one of the most common designs available and is what is shown in Figure 2, above. The raised lip\/saddle design is best suited for small flow control and is kept leak-proof thanks to the bonnet over the diaphragm and actuator. This design is optimal for dangerous or corrosive liquid and gas, as any failure with the membrane will be kept contained by this bonnet. Also, the sloped body makes this valve inherently self-draining, but this draining can happen in both valve directions which may not be optimal for some applications. The weir-type valve is mostly specified for clean, homogenous fluids, as viscous slurries and sediments may build up on either side of the saddle. They are most often found in processes such as food\/chemical, gas production, corrosive, and water applications.\r\n\r\n\r\n\r\n\r\nStraight Through Type Diaphragm Valves<\/h3>\r\n\r\n\r\n\r\n\r\nThe straight-through diaphragm valve is structurally similar to weir-types; however, it does not contain the characteristic saddle and instead has a completely straight pathway. Their membranes are typically more flexible and allow for farther travel distance, as it must touch the very bottom of the valve. These valves must often be serviced\/replaced, as their lifespan is typically less than weir-type designs due to their more flexible membranes. Straight-through diaphragm valves are used for slurries, viscous fluids, and other applications where blocking must be reduced. They are also useful for bi-directional flow regimes, as there is no saddle to impede swift changing from inlet to outlet.\r\n\r\n\r\n\r\n\r\nDiaphragm Valve Parts<\/h2>\r\n\r\n\r\n\r\n\r\nThe components of diaphragm valves are the following:\r\n\r\n\r\n\r\n\r\nDiaphragm Valve Bonnet<\/h3>\r\n\r\n\r\n\r\n\r\nThe bonnet serves as the top cover and is bolted to the valve body. It protects the compressor, stem, diaphragm, and other non-wetted components of the diaphragm valve.\r\n\r\n\r\n\r\n\r\nDiaphragm Valve Body<\/h3>\r\n\r\n\r\n\r\n\r\nThe valve body is the component directly connected to the pipeline wherein the fluid passes. The flow area inside the valve body depends on the type of diaphragm valve.\r\n\r\n\r\n\r\n\r\n\r\nBoth the valve body and bonnet are constructed from strong, rigid, and corrosive resistant materials.\r\n\r\n\r\n\r\n\r\nDiaphragm Valve Diaphragm<\/h3>\r\n\r\n\r\n\r\n\r\nThe diaphragm is made from a highly elastic polymeric disc that moves down to touch the bottom of the valve body to limit or obstruct the passage of fluid. The diaphragm lifts if the fluid flow rate is to be increased or the valve is to be fully opened. The fluid flows underneath the diaphragm. However, this component limits the valve\u2019s operating temperature and pressure due to the diaphragm\u2019s material and structure. It must also be replaced periodically since its mechanical properties degrade during usage.\r\n\r\n\r\n\r\n\r\n\r\nThe diaphragm isolates the non-wetted components (compressor, stem, and actuator) from the flowing media. Therefore, solids and viscous fluids are less likely to interfere with the operating mechanism of the diaphragm valve. This also protects the non-wetted components from corrosion. Conversely, the fluid in the pipeline will not be contaminated with the lubricant used in operating the valve.\r\n\r\n\r\n\r\n\r\nMaterial of Diaphragm Valve Diaphragm<\/h4>\r\n\r\n\r\n\r\n\r\nUnlined or Rubber Lined Type<\/strong>\r\n\r\n\r\n\r\n\r\n\r\n \t- NR\/Natural Rubber<\/li>\r\n \t
- NBR\/Nitrile\/Buna-N<\/li>\r\n \t
- EPDM<\/li>\r\n \t
- FKM\/Viton<\/li>\r\n \t
- BUNA-N<\/li>\r\n \t
- SI\/Silicone rubber<\/li>\r\n \t
- Leather<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n\r\nFluorine Plastic Type<\/strong>\r\n\r\n\r\n\r\n\r\n
\r\n \t- FEP, with EPDM backing<\/li>\r\n \t
- PTFE, with EPDM backing<\/li>\r\n \t
- PFA, with EPDM backing<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Diaphragm Valve Compressor<\/h3>\r\n\r\n\r\n\r\n\r\nThe compressor is a disc that lies between the valve stem and the diaphragm. It supports the diaphragm valve and distributes the forces from the stem during linear movement. The compressor design is optimized to provide better flow throttling and control.\r\n\r\n\r\n\r\n\r\nDiaphragm Valve Stem<\/h3>\r\n\r\n\r\n\r\n\r\nThe stem is a vertical shaft connected to the compressor that exerts linear motion to move both compressor and diaphragm, thus operating the diaphragm valve. It transmits the motion exerted by the actuator. Diaphragm valves can either have piston- or threaded-type stems. As the name implies, piston-type valves are moved by a piston assembly inside the bonnet, with the valve stem likely acting as the piston rod. This type requires linear force exerted by fluid pressure. Threaded stem valves have a matching stem nut. This type requires torque to linearly move the stem, as well as lubrication for smooth motion.\r\n\r\n\r\n\r\n\r\n\r\nThe threaded stems of diaphragm valves can have a rising or non-rising mechanism:\r\n\r\n\r\n\r\n\r\n\r\n \t- Rising Stem<\/strong>: Rising stems or indicating stems extend their length up to the handwheel. As the handwheel is turned, the stem rises or descends to open or close the valve, respectively. Hence, it is easier to determine the extent to which the valve is opened by looking at the amount of stem exposed. However, rising stems take up more space than non-rising stems.<\/li>\r\n \t
- Non-Rising Stem:<\/strong> Non-rising stems or non-indicating stems are rotated to open or close the valve, but it does not cause the stem to move up or down. Non-rising stem valves are used in limited spaces, such as in underground piping systems.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Advantages and Disadvantages of Diaphragm Valves<\/h2>\r\n\r\n\r\n\r\n\r\n
- Das Membranventil vom Wehrtyp ist eine der g\u00e4ngigsten Konstruktionen und wird in Abbildung 2 oben gezeigt. Die Konstruktion mit erh\u00f6hter Lippe\/Sattel eignet sich am besten f\u00fcr die Regelung kleiner Durchflussmengen und ist dank der Haube \u00fcber der Membran und dem Antrieb dicht. Diese Konstruktion ist optimal f\u00fcr gef\u00e4hrliche oder \u00e4tzende Fl\u00fcssigkeiten und Gase, da jeder Membranfehler durch diese Haube einged\u00e4mmt wird. Au\u00dferdem ist dieses Ventil durch den geneigten K\u00f6rper von Natur aus selbstentleerend, aber diese Entleerung kann in beide Ventilrichtungen erfolgen, was f\u00fcr manche Anwendungen nicht optimal sein kann. Das Wehrventil wird meist f\u00fcr saubere, homogene Fl\u00fcssigkeiten spezifiziert, da sich auf beiden Seiten des Sattels viskose Schl\u00e4mme und Sedimente ansammeln k\u00f6nnen. Man findet sie am h\u00e4ufigsten in Prozessen wie Lebensmittel-\/Chemie-, Gasproduktions-, Korrosions- und Wasseranwendungen.<\/li><\/ul><\/li>
- Membranventile mit geradem Durchgang<\/strong>
- Das Durchgangsmembranventil ist strukturell \u00e4hnlich wie Wehrventile, besitzt jedoch nicht den charakteristischen Sattel, sondern einen vollst\u00e4ndig geraden Weg. Ihre Membranen sind in der Regel flexibler und erm\u00f6glichen gr\u00f6\u00dfere Bewegungsdistanzen, da sie den Boden des Ventils ber\u00fchren m\u00fcssen. Diese Ventile m\u00fcssen h\u00e4ufig gewartet\/ausgetauscht werden, da ihre Lebensdauer aufgrund ihrer flexibleren Membranen in der Regel k\u00fcrzer ist als bei Wehrventilen. Durchgangsmembranventile werden f\u00fcr Schl\u00e4mme, viskose Fl\u00fcssigkeiten und andere Anwendungen verwendet, bei denen Verstopfungen reduziert werden m\u00fcssen. Sie sind auch f\u00fcr bidirektionale Str\u00f6mungsregime n\u00fctzlich, da kein Sattel vorhanden ist, der einen schnellen Wechsel von Einlass zu Auslass behindert.<\/li><\/ul><\/li><\/ul>\n\n\n\n
Vorteile von Membranventilen?<\/h2>\n\n\n\n
- Membranventile k\u00f6nnen auch f\u00fcr Drosselzwecke verwendet werden.<\/li>
- Aufgrund der gro\u00dfen Absperrfl\u00e4che entlang des Sitzes weist es im Wesentlichen die Drosseleigenschaften eines schnell \u00f6ffnenden Ventils auf.<\/li>
- Zur Regelung kleiner Durchfl\u00fcsse steht ein Wehrmembranventil zur Verf\u00fcgung.<\/li>
- Membranventile eignen sich besonders f\u00fcr den Umgang mit korrosiven Fl\u00fcssigkeiten, faserigen Schl\u00e4mmen, radioaktiven Fl\u00fcssigkeiten oder anderen Fl\u00fcssigkeiten, die frei von Verunreinigungen bleiben m\u00fcssen.<\/li>
- Der Betriebsmechanismus eines Membranventils ist nicht dem Medium in der Rohrleitung ausgesetzt. Klebrige oder viskose Fl\u00fcssigkeiten k\u00f6nnen nicht in die Ventilhaube gelangen und den Betriebsmechanismus beeintr\u00e4chtigen.<\/li>
- Viele Fl\u00fcssigkeiten, die die Funktionsteile der meisten anderen Ventiltypen verstopfen, korrodieren oder verkleben w\u00fcrden, passieren ein Membranventil ohne Probleme. Umgekehrt d\u00fcrfen Schmiermittel f\u00fcr den Betriebsmechanismus die zu behandelnde Fl\u00fcssigkeit nicht verunreinigen.<\/li>
- Es m\u00fcssen keine Stopfbuchsen gewartet werden und es besteht keine Gefahr einer Undichtigkeit der Ventilspindel.<\/li><\/ul>\n\n\n\n\n
Verwandte Tags:<\/h2>\n\n\n\n\n
\nZECO-Ventil<\/a>\n\n<\/div>\n\n\n\n\nUnterschied zwischen Absperrschieber und Absperrklappe<\/a>\n\n<\/div>\n\n\n\n\nWas sind Absperrventile?<\/a>\n\n<\/div>\n\n\n\n\nHersteller von manuell bet\u00e4tigten Absperrschiebern<\/a>\n\n<\/div>\n\n\n\n\nWas ist ein Absperrschieber?<\/a>\n\n<\/div>\n\n\n\n\nShanghai Druckminderventilfabrik<\/a>\n\n<\/div>\n\n\n\n\nWas sind automatische Regelventile?<\/a>\n\n<\/div>\n\n\n\n\nDurchgangsventil vs. Kugelhahn<\/a>\n\n<\/div>\n\n\n\n\n12-Zoll-Schieberventillieferant<\/a>\n\n<\/div>\n\n\n\n\nThermoplastische Materialien als Kugelhahnsitz und Absperrklappensitz<\/a>\n\n<\/div>","protected":false},"excerpt":{"rendered":"Membranventile sind in den meisten Situationen keine wichtige \u00dcberlegung. Aber wenn ein Ventil Ihre Leistung in nachgelagerten Prozessen verbessern kann, dann \u2026 Weiterlesen ...<\/a><\/p>","protected":false},"author":2,"featured_media":13348,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_generate-full-width-content":"","kt_blocks_editor_width":"","footnotes":""},"categories":[1],"tags":[2702,2704,2703,3205],"class_list":["post-3059","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-diaphragm-valve","tag-diaphragm-valve-diagram","tag-diaphragm-valve-function","tag-diaphragm-valve-manufacturers","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-50"],"featured_image_src_large":["https:\/\/zecovalve.com\/wp-content\/uploads\/2022\/01\/20220105083122-61d5575ae65f4.jpg",924,1004,false],"author_info":{"display_name":"Jerry","author_link":"https:\/\/zecovalve.com\/de\/author\/jerry"},"comment_info":0,"category_info":[{"term_id":1,"name":"Uncategorized","slug":"uncategorized","term_group":0,"term_taxonomy_id":1,"taxonomy":"category","description":"","parent":0,"count":452,"filter":"raw","cat_ID":1,"category_count":452,"category_description":"","cat_name":"Uncategorized","category_nicename":"uncategorized","category_parent":0}],"tag_info":[{"term_id":2702,"name":"Diaphragm Valve","slug":"diaphragm-valve","term_group":0,"term_taxonomy_id":2702,"taxonomy":"post_tag","description":"","parent":0,"count":3,"filter":"raw"},{"term_id":2704,"name":"diaphragm valve diagram","slug":"diaphragm-valve-diagram","term_group":0,"term_taxonomy_id":2704,"taxonomy":"post_tag","description":"","parent":0,"count":2,"filter":"raw"},{"term_id":2703,"name":"Diaphragm Valve Function","slug":"diaphragm-valve-function","term_group":0,"term_taxonomy_id":2703,"taxonomy":"post_tag","description":"\r\n\r\n\r\n\r\nGET DIAPHRAGM VALVE DIAGRAM INFORMATION<\/strong><\/a>\r\n\r\n\r\n\r\n\r\n
What is a Diaphragm Valve?<\/h2>\r\n\r\n\r\n\r\n\r\nDiaphragm valves get their name from a flexible disc that comes into contact with a seat at the top of the valve body to form a seal. A diaphragm is a flexible, pressure-responsive element that transmits force to open, close, or control a valve. Diaphragm valves are related to pinch valves, but use an elastomeric diaphragm, instead of an elastomeric liner in the valve body, to separate the flow stream from the closure element.\r\n\r\n\r\n\r\n\r\n
<\/figure>\r\n\r\n\r\n\r\nHow do Diaphragm Valves Work?<\/h2>\r\n\r\n\r\n\r\n\r\nDiaphragm valves are simple in construction and operation. A valve actuator is in contact with the inner membrane (or \u201cdiaphragm\u201d) of the valve in its open position. When the user desires the valve to be shut, the actuator is pressed and\/or turned and the membrane is pushed into the edge of the solid damn, closing the valve. Certain diaphragm valves can also have half open\/restricted positions where the membrane is partially closed, allowing a throttled flow through the valve. In the next section, we will examine the broad categories of diaphragm valves and where they are most useful.\r\n\r\n\r\n\r\n\r\n
Types of Diaphragm Valves<\/h2>\r\n\r\n\r\n\r\n
Weir-Type Diaphragm Valves<\/h3>\r\n\r\n\r\n\r\n\r\nThe weir-type diaphragm valve is one of the most common designs available and is what is shown in Figure 2, above. The raised lip\/saddle design is best suited for small flow control and is kept leak-proof thanks to the bonnet over the diaphragm and actuator. This design is optimal for dangerous or corrosive liquid and gas, as any failure with the membrane will be kept contained by this bonnet. Also, the sloped body makes this valve inherently self-draining, but this draining can happen in both valve directions which may not be optimal for some applications. The weir-type valve is mostly specified for clean, homogenous fluids, as viscous slurries and sediments may build up on either side of the saddle. They are most often found in processes such as food\/chemical, gas production, corrosive, and water applications.\r\n\r\n\r\n\r\n\r\n
Straight Through Type Diaphragm Valves<\/h3>\r\n\r\n\r\n\r\n\r\nThe straight-through diaphragm valve is structurally similar to weir-types; however, it does not contain the characteristic saddle and instead has a completely straight pathway. Their membranes are typically more flexible and allow for farther travel distance, as it must touch the very bottom of the valve. These valves must often be serviced\/replaced, as their lifespan is typically less than weir-type designs due to their more flexible membranes. Straight-through diaphragm valves are used for slurries, viscous fluids, and other applications where blocking must be reduced. They are also useful for bi-directional flow regimes, as there is no saddle to impede swift changing from inlet to outlet.\r\n\r\n\r\n\r\n\r\n
Diaphragm Valve Parts<\/h2>\r\n\r\n\r\n\r\n\r\nThe components of diaphragm valves are the following:\r\n\r\n\r\n\r\n\r\n
Diaphragm Valve Bonnet<\/h3>\r\n\r\n\r\n\r\n\r\nThe bonnet serves as the top cover and is bolted to the valve body. It protects the compressor, stem, diaphragm, and other non-wetted components of the diaphragm valve.\r\n\r\n\r\n\r\n\r\n
Diaphragm Valve Body<\/h3>\r\n\r\n\r\n\r\n\r\nThe valve body is the component directly connected to the pipeline wherein the fluid passes. The flow area inside the valve body depends on the type of diaphragm valve.\r\n\r\n\r\n\r\n\r\n\r\nBoth the valve body and bonnet are constructed from strong, rigid, and corrosive resistant materials.\r\n\r\n\r\n\r\n\r\n
Diaphragm Valve Diaphragm<\/h3>\r\n\r\n\r\n\r\n\r\nThe diaphragm is made from a highly elastic polymeric disc that moves down to touch the bottom of the valve body to limit or obstruct the passage of fluid. The diaphragm lifts if the fluid flow rate is to be increased or the valve is to be fully opened. The fluid flows underneath the diaphragm. However, this component limits the valve\u2019s operating temperature and pressure due to the diaphragm\u2019s material and structure. It must also be replaced periodically since its mechanical properties degrade during usage.\r\n\r\n\r\n\r\n\r\n\r\nThe diaphragm isolates the non-wetted components (compressor, stem, and actuator) from the flowing media. Therefore, solids and viscous fluids are less likely to interfere with the operating mechanism of the diaphragm valve. This also protects the non-wetted components from corrosion. Conversely, the fluid in the pipeline will not be contaminated with the lubricant used in operating the valve.\r\n\r\n\r\n\r\n\r\n
Material of Diaphragm Valve Diaphragm<\/h4>\r\n\r\n\r\n\r\n\r\nUnlined or Rubber Lined Type<\/strong>\r\n\r\n\r\n\r\n\r\n
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- NR\/Natural Rubber<\/li>\r\n \t
- NBR\/Nitrile\/Buna-N<\/li>\r\n \t
- EPDM<\/li>\r\n \t
- FKM\/Viton<\/li>\r\n \t
- BUNA-N<\/li>\r\n \t
- SI\/Silicone rubber<\/li>\r\n \t
- Leather<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n\r\nFluorine Plastic Type<\/strong>\r\n\r\n\r\n\r\n\r\n
- \r\n \t
- FEP, with EPDM backing<\/li>\r\n \t
- PTFE, with EPDM backing<\/li>\r\n \t
- PFA, with EPDM backing<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Diaphragm Valve Compressor<\/h3>\r\n\r\n\r\n\r\n\r\nThe compressor is a disc that lies between the valve stem and the diaphragm. It supports the diaphragm valve and distributes the forces from the stem during linear movement. The compressor design is optimized to provide better flow throttling and control.\r\n\r\n\r\n\r\n\r\n
Diaphragm Valve Stem<\/h3>\r\n\r\n\r\n\r\n\r\nThe stem is a vertical shaft connected to the compressor that exerts linear motion to move both compressor and diaphragm, thus operating the diaphragm valve. It transmits the motion exerted by the actuator. Diaphragm valves can either have piston- or threaded-type stems. As the name implies, piston-type valves are moved by a piston assembly inside the bonnet, with the valve stem likely acting as the piston rod. This type requires linear force exerted by fluid pressure. Threaded stem valves have a matching stem nut. This type requires torque to linearly move the stem, as well as lubrication for smooth motion.\r\n\r\n\r\n\r\n\r\n\r\nThe threaded stems of diaphragm valves can have a rising or non-rising mechanism:\r\n\r\n\r\n\r\n\r\n
- \r\n \t
- Rising Stem<\/strong>: Rising stems or indicating stems extend their length up to the handwheel. As the handwheel is turned, the stem rises or descends to open or close the valve, respectively. Hence, it is easier to determine the extent to which the valve is opened by looking at the amount of stem exposed. However, rising stems take up more space than non-rising stems.<\/li>\r\n \t
- Non-Rising Stem:<\/strong> Non-rising stems or non-indicating stems are rotated to open or close the valve, but it does not cause the stem to move up or down. Non-rising stem valves are used in limited spaces, such as in underground piping systems.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Advantages and Disadvantages of Diaphragm Valves<\/h2>\r\n\r\n\r\n\r\n
\r\n - Non-Rising Stem:<\/strong> Non-rising stems or non-indicating stems are rotated to open or close the valve, but it does not cause the stem to move up or down. Non-rising stem valves are used in limited spaces, such as in underground piping systems.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
- Rising Stem<\/strong>: Rising stems or indicating stems extend their length up to the handwheel. As the handwheel is turned, the stem rises or descends to open or close the valve, respectively. Hence, it is easier to determine the extent to which the valve is opened by looking at the amount of stem exposed. However, rising stems take up more space than non-rising stems.<\/li>\r\n \t
- Das Durchgangsmembranventil ist strukturell \u00e4hnlich wie Wehrventile, besitzt jedoch nicht den charakteristischen Sattel, sondern einen vollst\u00e4ndig geraden Weg. Ihre Membranen sind in der Regel flexibler und erm\u00f6glichen gr\u00f6\u00dfere Bewegungsdistanzen, da sie den Boden des Ventils ber\u00fchren m\u00fcssen. Diese Ventile m\u00fcssen h\u00e4ufig gewartet\/ausgetauscht werden, da ihre Lebensdauer aufgrund ihrer flexibleren Membranen in der Regel k\u00fcrzer ist als bei Wehrventilen. Durchgangsmembranventile werden f\u00fcr Schl\u00e4mme, viskose Fl\u00fcssigkeiten und andere Anwendungen verwendet, bei denen Verstopfungen reduziert werden m\u00fcssen. Sie sind auch f\u00fcr bidirektionale Str\u00f6mungsregime n\u00fctzlich, da kein Sattel vorhanden ist, der einen schnellen Wechsel von Einlass zu Auslass behindert.<\/li><\/ul><\/li><\/ul>\n\n\n\n