{"id":6656,"date":"2026-05-07T11:00:48","date_gmt":"2026-05-07T08:00:48","guid":{"rendered":"https:\/\/ukspar.ua\/?p=6656"},"modified":"2026-06-23T17:00:34","modified_gmt":"2026-06-23T14:00:34","slug":"princzipi-roboti-zapirnoi-ta-regulyuyuchoi-armaturi","status":"publish","type":"post","link":"https:\/\/ukspar.ua\/en\/blog\/princzipi-roboti-zapirnoi-ta-regulyuyuchoi-armaturi\/","title":{"rendered":"Principles of operation of shut-off and control valves"},"content":{"rendered":"<p>Pipe fittings perform different functions depending on their purpose. Some products completely block the flow, others smoothly regulate it, and still others combine both functions. Choose <a href=\"https:\/\/ukspar.ua\/en\/armatura-dlya-vodopostachannya\/\">water shut-off valve<\/a> UKSPAR specialists will help you with the necessary parameters.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What are shut-off and regulating valves?<\/h2>\n\n\n\n<p>What is a shut-off valve? This is the question that begins the competent selection of pipeline valves.<\/p>\n\n\n\n<ul>\n<li>Shut-off valves are a class of pipeline products that operate in two extreme positions: fully open or fully closed. Shut-off valves include gate valves, ball valves, stop valves, and butterfly valves.<\/li>\n\n\n\n<li>Control valves are valves that smoothly change the throughput of a pipeline from zero to maximum. They include: control valves, balancing valves, pressure reducers, and throttle discs.<\/li>\n\n\n\n<li>Shut-off and control valves (or shut-off and control valves) are a conventional category that combines the functions of shut-off and control. A typical example is a control valve with a \u00abclosed\u00bb position or a shut-off valve that can be used to partially block the flow. and butterfly valves\u201c<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">How does a shut-off valve differ from a regulating valve?<\/h3>\n\n\n\n<p>The key difference is in the design of the shut-off element and the permissible operating mode. The shut-off valve is designed for minimal hydraulic resistance in the open position and complete tightness in the closed position.<\/p>\n\n\n\n<p>Control valves, on the other hand, are designed for continuous operation with a partially open flow cross-section. Their valve has a special profile shape (parabolic, V-shaped, linear profile) that ensures a uniform and predictable change in flow rate depending on the stroke of the stem.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The principle of operation of shut-off valves<\/h2>\n\n\n\n<p>Regardless of the type of design, the principle of operation of shut-off valves is to move a shut-off element that closes or opens the passage section.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How gate valves and ball valves work<\/h3>\n\n\n\n<p>Gate valve \u2014 a closing element (wedge or parallel disk) moves perpendicular to the flow axis. When the flywheel or handwheel rotates, the spindle moves the wedge between the seats. In the open position, the wedge completely leaves the flow zone, providing minimal hydraulic resistance. In the closed position, it is tightly pressed against the seats, blocking the movement of the medium.<\/p>\n\n\n\n<p>Gate valves are divided into wedge (a monolithic wedge) and parallel (two discs with a spacer between them). Wedge gates provide reliable closure even with a small pressure drop; parallel gates cope better with conditions where thermal expansion is possible.<\/p>\n\n\n\n<p>A ball valve is a shut-off element in the form of a metal ball with a through hole. By turning the handle 90\u00b0, you move the hole to the position &quot;along the flow axis&quot; (open) or &quot;perpendicular to the flow&quot; (closed). The seal occurs between the surface of the ball and the soft seats.<\/p>\n\n\n\n<p>The ball valve operates very quickly - one movement of the handle in a fraction of a second. This makes it indispensable where a quick emergency shutdown is required.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Where is water shut-off valve used?<\/h3>\n\n\n\n<p>Water shut-off valves are a general name for all types of products used in water supply systems. They are installed:<\/p>\n\n\n\n<ul>\n<li>on the introduction of water supply into the building;<\/li>\n\n\n\n<li>before meters and filters;<\/li>\n\n\n\n<li>at junctions between apartments or floors;<\/li>\n\n\n\n<li>in front of plumbing fixtures (faucets, toilets);<\/li>\n\n\n\n<li>in fire extinguishing systems;<\/li>\n\n\n\n<li>at pumping stations and water supply stations.<\/li>\n\n\n\n<li>on water supply mains<\/li>\n<\/ul>\n\n\n\n<p>Water shut-off valves have increased requirements for materials: they must be safe for drinking water and meet sanitary standards.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The principle of operation of regulating valves<\/h2>\n\n\n\n<p>Control valves are not designed to completely shut off the flow, but to precisely control its parameters in the pipeline system.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How is the flow of the working medium regulated?<\/h3>\n\n\n\n<p>Flow regulation is achieved by changing the cross-section of the valve, that is, the area through which the medium passes. When the cross-section is reduced, the hydraulic resistance increases, the flow rate and pressure behind the valve decrease. When it is increased, the opposite happens.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Control valves and their features<\/h3>\n\n\n\n<p>The control valve consists of:<\/p>\n\n\n\n<ul>\n<li>bodies with one or two saddles;<\/li>\n\n\n\n<li>profiled shutter (plunger);<\/li>\n\n\n\n<li>a rod connecting the shutter to the actuator;<\/li>\n\n\n\n<li>drive - pneumatic, electric or hydraulic.<\/li>\n<\/ul>\n\n\n\n<p>Pneumatic actuators respond quickly and reliably, which is why they are used in industrial automation. Electric actuators are more compact and easier to integrate into digital control systems. Hydraulic actuators develop high forces - necessary for powerful valves with large diameters.<\/p>\n\n\n\n<p>Water-distributing fittings (faucets, water-drawing valves) are a separate subclass where the regulation is done manually. The mixing mechanism combines the flows of hot and cold water in a given proportion.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Main types of shut-off and control valves<\/h2>\n\n\n\n<p>In practice, the boundary between &quot;purely shut-off&quot; and &quot;control&quot; valves is not always clear. Shut-off and control valves include:<\/p>\n\n\n\n<ul>\n<li>Regulating shut-off valves can both shut off and regulate, but their control characteristics are worse than those of specialized control valves.<\/li>\n\n\n\n<li>Balancing valves - maintain a set pressure drop in a hydraulic system; often have a &quot;closed&quot; position.<\/li>\n\n\n\n<li>Thermostatic valves - react to temperature changes, automatically regulating the flow of coolant to the radiator.<\/li>\n\n\n\n<li>Pressure reducers - reduce the pressure from the main to a set point, automatically maintaining it at a constant level.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Pipeline fittings classification<\/h2>\n\n\n\n<p>The classification of pipeline fittings is based on several independent criteria.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><td>\n<p><strong>Principle<\/strong><\/p>\n<\/td><td>\n<p><strong>Type of reinforcement<\/strong><\/p>\n<\/td><td>\n<p><strong>Examples<\/strong><\/p>\n<\/td><\/tr><\/thead><tbody><tr><td>\n<p>Locking<\/p>\n<\/td><td>\n<p>Full opening\/closing<\/p>\n<\/td><td>\n<p>Gate valve, ball valve, valve<\/p>\n<\/td><\/tr><tr><td>\n<p>Regulatory<\/p>\n<\/td><td>\n<p>Smooth flow rate change<\/p>\n<\/td><td>\n<p>Control valve, balancing valve<\/p>\n<\/td><\/tr><tr><td>\n<p>Preventive<\/p>\n<\/td><td>\n<p>Automatic protection<\/p>\n<\/td><td>\n<p>Safety valve, pressure valve<\/p>\n<\/td><\/tr><tr><td>\n<p>Reverse<\/p>\n<\/td><td>\n<p>Automatic lock<\/p>\n<\/td><td>\n<p>Check valve<\/p>\n<\/td><\/tr><tr><td>\n<p>Distributive<\/p>\n<\/td><td>\n<p>Flow distribution<\/p>\n<\/td><td>\n<p>Three-way valve, distribution valve<\/p>\n<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Classification by type of control<\/h3>\n\n\n\n<p>The following types of control are distinguished:<\/p>\n\n\n\n<ul>\n<li>Manual - flywheel, handwheel, handle. The simplest and most reliable. The operator directly controls the position of the shutter.<\/li>\n\n\n\n<li>Mechanical with a gearbox - for large DN valves and taps, where significant effort is required to return.<\/li>\n\n\n\n<li>Electric - the electric actuator is connected to the spindle or shaft of the valve. Allows remote and automatic control.<\/li>\n\n\n\n<li>Pneumatic \u2014 driven by compressed air or gas. Fast response, high reliability.<\/li>\n\n\n\n<li>Hydraulic \u2014 driven by pressurized fluid. For high forces.<\/li>\n\n\n\n<li>Automatic (self-acting) \u2014 responds to changes in environmental parameters without an external signal (check valves, safety valves, pressure regulators).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Where are shut-off and control valves used?<\/h2>\n\n\n\n<p>Shut-off and control valves are used in all industries where there are pipeline systems:<\/p>\n\n\n\n<ul>\n<li>Heat supply and housing and utilities: balancing and thermostatic valves in heating systems, valves on main pipelines.<\/li>\n\n\n\n<li>Water supply and drainage: pressure reducers, check valves, valves and gates on networks.<\/li>\n\n\n\n<li>Industry: control valves on process lines, safety valves on reactors and boilers.<\/li>\n\n\n\n<li>Energy: steam and boiler feedwater fittings, valves on the steam manifold.<\/li>\n\n\n\n<li>Oil and gas industry: gate valves and control valves on wells and main oil pipelines.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Key parameters for selecting fittings<\/h2>\n\n\n\n<p>When selecting a pipeline valve, it is necessary to take into account the operating conditions of the system, the characteristics of the working environment and the requirements for the reliability of the unit. The main guidelines are the operating pressure, temperature, pipeline diameter, body material, connection type and frequency of operation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Selection by pressure, temperature and diameter<\/h2>\n\n\n\n<p>When selecting fittings, three basic parameters are used:<\/p>\n\n\n\n<ol>\n<li>DN (nominal diameter) - must correspond to the internal diameter of the pipeline. Narrowing (DN of the fitting &lt; DN of the pipe) increases hydraulic resistance; widening is not economical.<\/li>\n\n\n\n<li>PN (conditional pressure) - is selected with a margin of at least 10\u201320% relative to the maximum working pressure, taking into account possible water hammer.<\/li>\n\n\n\n<li>Temperature - the temperature and pressure drop is checked according to the passport characteristics.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">How to choose a tightness class<\/h2>\n\n\n\n<p>The tightness class determines the permissible leakage through a closed valve at a given pressure. The EN 12266 standard divides valves into classes A, B, C, D, E, F, G - where class A means zero leakage (metal to metal), and class G means the most permissible leakage.<\/p>\n\n\n\n<p>For gas systems and systems with toxic media, class A or B is required. For water supply, class C or D is sufficient. For non-critical industrial systems, class E\u2013F is acceptable.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Advantages and disadvantages of different types of reinforcement<\/h2>\n\n\n\n<p>Each type of pipe fitting has its own strengths, limitations, and optimal application conditions.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Which fittings are best for different tasks?<\/h3>\n\n\n\n<p>Gate valve: advantage - minimal hydraulic resistance, long durability; disadvantage - slow switching, long construction length.<\/p>\n\n\n\n<p>Ball valve: advantage - fast response, compactness, ease of maintenance; disadvantage - limited diameter of application, not recommended for adjustment.<\/p>\n\n\n\n<p>Rotary valve: advantage - compact, lightweight, cheap at large DN; disadvantage - higher hydraulic resistance, pressure and temperature limitations.<\/p>\n\n\n\n<p>Control valve: advantage - precise adjustment, wide Kv range; disadvantage - high cost, requires maintenance, not designed for quick complete shut-off.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Typical mistakes when choosing pipe fittings<\/h2>\n\n\n\n<p>Using a gate valve or ball valve as a regulating element. Operation in a half-open position leads to cavitation, vibration and accelerated wear. Use specialized regulating fittings for regulation.<\/p>\n\n\n\n<p>Ignoring the Cv\/Kv characteristic when selecting a control valve. An incorrectly selected Kv (flow coefficient) leads either to the inability to provide the required flow rate, or to the valve operating in extreme positions where the control is unstable.<\/p>\n\n\n\n<p>Selecting fittings without considering the aggressiveness of the environment. Standard fittings made of gray cast iron or carbon steel quickly fail in chemically aggressive conditions.<\/p>\n\n\n\n<p>Ignoring tightness requirements. For gas and vacuum systems, the tightness class is a critically important parameter that should not be ignored for the sake of savings.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p>Shut-off and regulating valves perform different tasks in pipeline systems. Shut-off valves provide reliable flow shut-off; regulating valves precisely maintain set parameters.<\/p>","protected":false},"excerpt":{"rendered":"<p>\u0422\u0440\u0443\u0431\u043e\u043f\u0440\u043e\u0432\u0456\u0434\u043d\u0430 \u0430\u0440\u043c\u0430\u0442\u0443\u0440\u0430 \u0432\u0438\u043a\u043e\u043d\u0443\u0454 \u0440\u0456\u0437\u043d\u0456 \u0444\u0443\u043d\u043a\u0446\u0456\u0457 \u0437\u0430\u043b\u0435\u0436\u043d\u043e \u0432\u0456\u0434 \u0441\u0432\u043e\u0433\u043e \u043f\u0440\u0438\u0437\u043d\u0430\u0447\u0435\u043d\u043d\u044f. \u041e\u0434\u043d\u0456 \u0432\u0438\u0440\u043e\u0431\u0438 \u043f\u043e\u0432\u043d\u0456\u0441\u0442\u044e \u043f\u0435\u0440\u0435\u043a\u0440\u0438\u0432\u0430\u044e\u0442\u044c \u043f\u043e\u0442\u0456\u043a, \u0456\u043d\u0448\u0456 \u2014 \u043f\u043b\u0430\u0432\u043d\u043e \u0439\u043e\u0433\u043e \u0440\u0435\u0433\u0443\u043b\u044e\u044e\u0442\u044c, \u0442\u0440\u0435\u0442\u0456 \u043f\u043e\u0454\u0434\u043d\u0443\u044e\u0442\u044c \u043e\u0431\u0438\u0434\u0432\u0456 \u0444\u0443\u043d\u043a\u0446\u0456\u0457. \u041f\u0456\u0434\u0456\u0431\u0440\u0430\u0442\u0438 \u0437\u0430\u043f\u0456\u0440\u043d\u0443 \u0430\u0440\u043c\u0430\u0442\u0443\u0440\u0443 \u0434\u043b\u044f \u0432\u043e\u0434\u0438 \u0437\u0430 \u043f\u043e\u0442\u0440\u0456\u0431\u043d\u0438\u043c\u0438 \u043f\u0430\u0440\u0430\u043c\u0435\u0442\u0440\u0430\u043c\u0438 \u0432\u0430\u043c \u0434\u043e\u043f\u043e\u043c\u043e\u0436\u0443\u0442\u044c \u0444\u0430\u0445\u0456\u0432\u0446\u0456 UKSPAR. \u0429\u043e \u0442\u0430\u043a\u0435 \u0437\u0430\u043f\u0456\u0440\u043d\u0430 \u0442\u0430 \u0440\u0435\u0433\u0443\u043b\u044e\u044e\u0447\u0430 \u0430\u0440\u043c\u0430\u0442\u0443\u0440\u0430 \u0429\u043e \u0442\u0430\u043a\u0435 \u0437\u0430\u043f\u0456\u0440\u043d\u0430 \u0430\u0440\u043c\u0430\u0442\u0443\u0440\u0430 \u2014 \u043f\u0438\u0442\u0430\u043d\u043d\u044f, \u0437 \u044f\u043a\u043e\u0433\u043e \u043f\u043e\u0447\u0438\u043d\u0430\u0454\u0442\u044c\u0441\u044f \u0433\u0440\u0430\u043c\u043e\u0442\u043d\u0438\u0439 \u043f\u0456\u0434\u0431\u0456\u0440 \u0442\u0440\u0443\u0431\u043e\u043f\u0440\u043e\u0432\u0456\u0434\u043d\u043e\u0457 \u0430\u0440\u043c\u0430\u0442\u0443\u0440\u0438. \u0427\u0438\u043c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6662,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[809],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/posts\/6656"}],"collection":[{"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/comments?post=6656"}],"version-history":[{"count":6,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/posts\/6656\/revisions"}],"predecessor-version":[{"id":6677,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/posts\/6656\/revisions\/6677"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/media\/6662"}],"wp:attachment":[{"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/media?parent=6656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/categories?post=6656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ukspar.ua\/en\/wp-json\/wp\/v2\/tags?post=6656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}