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CHECK-VALVES

CHECK-VALVES
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CHECK-VALVES

Product catalog summary
Overview: The document provides comprehensive details on GESTRA non-return (check) valves used in HVAC systems, sanitary applications, and industrial technology. These valves ensure unidirectional flow, preventing reverse flow and protecting systems from damage.
Specifications and Features:
  • Non-return valves are essential in steam and condensate systems to prevent reverse flow and water hammer.
  • Types include DISCO® non-return valves, DISCOCHECK® dual-plate check valves, and swing check valves.
  • Materials used include brass, bronze, stainless steel, and special alloys like Hastelloy C.
  • Valves are designed for low weight, compact size, and can be installed in any position except those without springs.
Applications:
  • Used in heating, venting, air-conditioning, and industrial plants.
  • Specific valves like RK 70 and RK 71 are designed for low-noise operation in heating systems.
  • Valves like RK 44S are suitable for seawater and drinking water applications.
Installation and Operation:
  • Valves can be installed in various positions and are designed for easy maintenance and replacement without system drainage.
  • Gravity circulation checks prevent unwanted circulation in heating systems when pumps are off.
Standards and Compliance:
  • Valves comply with EU Pressure Equipment Directive 97/23/EC and are tested for tightness according to DIN EN 12266-1.
  • Available in various pressure ratings from PN 6 to PN 400, suitable for different media including corrosive substances.
Conclusion: GESTRA non-return valves offer reliable solutions for ensuring unidirectional flow in various systems, with a wide range of materials and designs to suit specific industrial and HVAC applications.
Additional Specifications:
  • Austenitic steel materials are used for components like RK 29A and RK 49, suitable for high temperatures and different pressure ratings (PN 63 to 160, with options for PN 400 and Class 2500).
  • Valves are designed for international standards, including DIN/EN, ASME, and BS.
Non-Return (Check) Valves:
  • GESTRA DISCO® non-return valves RK 86 and 86A feature a patented centering mechanism with four guide ribs for improved wear resistance and reliability.
  • They offer low wear, cost savings, better guidance, optimum tightness, and easy installation.
Dual-Plate Check Valves:
  • GESTRA DISCOCHECK® dual-plate check valves BB are designed for lightness and low resistance, with excellent hydrodynamic properties.
  • Available in DIN and ASME ranges, with options for anti-corrosion linings and special springs to reduce waterhammer effects.
Materials and Options:
  • Materials include grey cast iron, carbon steel, and austenitic steel.
  • Optional features include anti-corrosion linings, soft seats, and adjustable dampers for specific conditions.
Noise Issues and Solutions:
  • Noise can occur during start-up, shut-down, or partial load, often due to oversized valves.
  • Solutions include reducing the closing force by using a weaker spring or no spring at all, especially in vertical pipelines with upward flow.
Valve Operation:
  • Check valves open when a static pressure differential is established, overcoming the closing force.
  • Proper selection and sizing are crucial to prevent clatter and premature wear.
Recommendations: Choosing the correct non-return valve and adapting it optimally for the plant is essential to prevent operational issues. The document provides examples of applications for different valve types and offers support for specific requirements.
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Catalog excerpts

CHECK-VALVES-1

FLOWSERVE GESTRA Non-Return (Check) Valves For HVAC systems, sanitary applications and industrial technology

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CHECK-VALVES-2

Non-Return (Check) Valves in Steam and Condensate Systems Electrical pressure control Steam dryer/ purifier Electrical temperature control Steam flow measurement Mechanical temperature control Heat exchanger Production Measurement data Deaerating unit Measurement data from boiler house Controlled from the condensate side Steam flow measurement Process steam Condensate tank Flash vessel Intermittent boiler blowdown Heat exchanger Flash vessel Fresh/soft water Cooling water Cooling water Sight glass Steam trap Blowdown receiver Non-return valve V a acuum breaker prevents vacuum formation and E...

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CHECK-VALVES-3

Non-Return (Check) Valves Non-Return (Check) Valves in HVAC Technology Ensuring unidirectional flow prevents reverse running when pumps arranged in parallel are switched over GESTRA Gravity Circulation Checks SBO . . . . . . . . . . . . . . . . . . . . . . 4–5 GESTRA DISCO® Non-Return Valves . . . . . . . . . . . . . . . . . . 6–9 GESTRA DISCO® Non-Return Valves RK . . . . . . . . . . . . . 10–13 Return flow GESTRA DISCO® Non-Return Valves RK 86 and 86 A . . . 14–15 Foot valve stops the suction line from running dry when the pump is switched off Burner with pump Return line GESTRA DISCOCHECK®...

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CHECK-VALVES-4

GESTRA Gravity Circulation Checks SBO These check valves are used for preventing gravity circulation in heating and hot-water systems. As soon as the opening force decreases and the closing force is greater, the gravity circulation check closes again . With its three SBO types, GESTRA offers the right gravity circulation check for every pump connection . The SBO 11 and SBO 21 valves can replace the isolating valve in the supply line . These valves remain in the line should the pump have to be removed or exchanged . The benefit: the plant need no longer be completely emptied . Gravity circulation...

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CHECK-VALVES-5

Non-Return (Check) Valves The guide resists wear and is corrosionresistant. Jamming and canting of the valve cone are excluded GESTRA gravity circulation checks are available with connections meeting all installation requirements. Available designs with either male or female thread for PN 6, 1–2" BSP Spring opening pressure w The spring forces are adapted to the special use of the valve as gravity circulation checks and positively prevent gravity circulation Shut-off w The use of plastic valve cones ensures quiet operation. The SBO 11 and SBO 21 valves in addition are supplied with a seat gasket...

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CHECK-VALVES-6

GESTRA DISCO® Non-Return Valves Today GESTRA can look back with pride on one hundred years of experience in valve manufacture. The company offers a broad range of DISCO® non-return valves tailored to fulfil the most diverse of applications and customer requirements. All valves are made of diverse materials to meet particular demands, and the individual valve components are optimally coordinated with each other. Through this ideal mixture of different components in the range of standard valves, the best valve can be delivered for almost every application. Here it does not matter whether a thermally...

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CHECK-VALVES-7

Non-Return (Check) Valves Functional principle The spring-assisted DISCO® non-return valve opens when the opening force exceeds the closing force. The opening force depends on the pressure or the volume flow, and the closing force on the tension of the closing spring, on the closing weight, on the installation position and the size of the nonreturn valve. GESTRA DISCO® non-return valve in the fully open state GESTRA DISCO® non-return valve in the closed state GESTRA DISCO® non-return valve with spiral centering, DN 15–100 ( 1/ 2 –4“) GESTRA DISCO® non-return valve with self-centering body, DN...

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CHECK-VALVES-8

GESTRA DISCO® Non-Return Valves Short overall length, low weight Connections of your choice Tight shut-off Valves with short face-to-face dimensions reduce the weight and size of a plant. As the figure below demonstrates, the overall length of a GESTRA non-return valve is only 1/8 that of a conventional non-return valve. The overall lengths comply with DIN EN 558, series 49 and 52 (K4/K5). For flanges to DIN EN 1092-1, form B1/B2/D/F, to ASME RF/RJ, or to works standards GESTRA non-return valves are tested according to DIN EN 12266-1, with water or air as the medium. This corresponds to the outdated...

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CHECK-VALVES-9

Non-Return (Check) Valves Valves with soft seat Valve type Non-return valves provided with a metallic disc are also available on request with a soft seat made of: w EPDM (ethylene-propylene rubber) suitable for water and steam, –40 to +150 °C. w FPM (fluoro-rubber) for mineral oil and gases, –25 to +200 °C. w PTFE (Teflon) for corrosive media, –190 to +250 °C. Hot-pressed brass / valve disc of plastic For flanges PN 6 / 10 / 16 Heating installations up to 100°C, compressed-air systems Hot-pressed brass / valve disc of austenitic steel For flanges PN 6 / 10 / 16 Heating installations, higher temperatures...

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CHECK-VALVES-10

GESTRA DISCO® Non-Return Valves RK Valve types For the sector of heating, venting and air-conditioning, various non-return valves are available for a wide range of requirements. The RK 70 is a low-noise non-return valve, so you see what your heating system gives you but do not hear it. Quality at low cost is offered by the RK 71, whilst the RK 41 is our universal and flexible valve satisfying diverse requirements in HVAC technology. Or do you need a valve for a drinking water system, in which no brass may be used? Or one suitable for low temperatures? Then you should take the RK 44. The RK 44S...

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CHECK-VALVES-11

Non-Return (Check) Valves The special shape always guarantees a centralized positioning of the spring. Material: austenitic steel Austenitic steel, metal-to-metal seat. RK 41 and RK 44 can alternatively be provided with a soft seat The degree of tightness lies well within the tolerances permitted in DIN EN 12266-1 Four guide ribs are used to ensure low-wear operation. From DN 125 (5"), the valve cone is guided by a spindle/ sleeve arrangement Using different springs for the RK 41 and RK 44 per­­­ mits variation of the opening pressure to meet the operating requirements Wafer-type valve for DIN/EN,...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.