Butterfly valves are widely used in industrial piping systems due to their compact structure, lightweight design, and quick operation. They are commonly applied in water treatment, chemical, power, oil, and gas industries. However, when dealing with industrial standards across different countries and regions, selecting a butterfly valve that meets the relevant specifications is crucial. This article provides a detailed analysis of butterfly valve design and selection requirements based on three key standards: API 609, ISO 5752, and GB/T 12238. 1. API 609 — American Petroleum Institute Standard API 609 is the American Petroleum Institute (API) standard for metal-seated butterfly valves, primarily used in the oil, gas, and chemical industries. The standard defines valve structure, materials, dimensions, and pressure ratings to ensure reliable performance under high temperature, high pressure, and corrosive media conditions. Key points include: ● Pressure Ratings: Covers Class 150 to 1500, accommodating various service conditions. ● Body and Disc Design: Metal-to-metal sealing requires precise alignment between disc and seat to prevent leakage under high temperature or high pressure. ● Testing and Inspection: Includes shell tests, seat leakage tests, and operational performance checks to ensure valve safety and reliability. For high-temperature steam or high-pressure oil and gas pipelines, selecting a butterfly valve compliant with API 609 can significantly reduce leakage risk and extend equipment lifespan. 2. ISO 5752 — International Standard Organization Standard ISO 5752 is the International Organization for Standardization (ISO) standard that specifies end dimensions and flange connection sizes for valves. It defines the face-to-face dimensions, flange sizes, and connection methods for butterfly valves, providing a consistent interface specification for industrial users worldwide. Key points include: ● Face-to-Face Dimensions: Specifies valve lengths for different nominal diameters to ensure compatibility with piping systems. ● Flange Dimensions: Ensures valves match international standard pipe fittings, such as ANSI or DIN flanges. ● Interchangeability: Butterfly valves designed according to ISO 5752 can be replaced or serviced globally without redesigning the pipeline interface. ISO 5752 is particularly suitable for multinational engineering projects, ensuring the universality of butterfly valves across different plants and systems. 3. JB/T8527 — Chinese National Standard JB/T8527 is the Chinese national standard specifying the dimensions, structure, and testing requirements for metal hard-seal butterfly valves. It is widely applied in domestic industrial projects such as water conservancy, power, and petrochemical industries, serving as an important reference for procurement and acceptance. Key ...
Check valves are often considered the most “quiet” yet essential components in a piping system. Their primary function is to prevent backflow and safeguard pumps, compressors, and the overall stability of the system. However, in real-world applications, poor sealing—commonly referred to as “leakage”—is one of the most frequent and frustrating issues encountered in check valve operation. When a check valve fails to seal properly, it can reduce system efficiency, trigger pressure fluctuations, cause water hammer, and even damage critical equipment. This article breaks down the technical causes behind check valve leakage and offers practical diagnostic and corrective measures to help you quickly identify and resolve sealing problems, even under challenging operating. 1. Why Does a Check Valve Fail to Close Properly? Common Causes Explained 1. Presence of Particles or Solid Impurities in the Medium Solid particles can become trapped between the disc and the seat, preventing full contact and causing slight or even noticeable leakage. Typical signs include: ● Significant leakage at small opening positions ● Leakage decreases after cleaning 2. Disc Wear or Seat Damage Frequent cycling, corrosive media, or high-velocity flow can wear the sealing surfaces, resulting in scratches, pits, or deformation. This issue is especially common in high-temperature steam systems. 3. Incorrect Installation Direction or Insufficient Tilt Angle Although it may sound like a basic mistake, incorrect installation still occurs on many job sites. Since check valves rely heavily on gravity and flow direction, improper installation prevents the disc from returning to its closed position smoothly. 4. Flow Velocity Too Low to Create Adequate Differential Pressure A check valve opens through fluid flow. When the flow rate is too low, the disc may flutter or fail to close completely, leading to leakage. Common scenarios include: ● Insufficient straight-pipe length ● Frequent pump start/stop ● Poorly designed low-flow systems 5. Disc Sticking or Hinge Mechanism Not Operating Smoothly In swing check valves, rust, corrosion, or lack of lubrication at the hinge pin or disc connection may cause sticking, preventing full closure. 6. Thermal Deformation of Sealing Surfaces Due to Temperature Fluctuations In high-temperature conditions such as steam service, thermal expansion and contraction can slightly deform sealing surfaces, resulting in an imperfect seal. 2. How to Quickly Determine If a Check Valve Is Not Closing Properly? 1. Abnormal Pressure Gauge Readings If the inlet pressure remains stable while the outlet pressure gradually rises, backflow caused by check-valve leakage is the most likely reason. 2. Pipe Vibration or Light Knocking Sounds This indicates that the disc is oscillating at high frequency, often due to insufficient flow velocity or a loose dis...
Recently, representatives from Dervos Valve visited long-term industrial valve partners in Norway, Italy, Germany, and Spain. The multi-day trip focused on understanding customers’ current project requirements and discussing future procurement plans and technical specifications in greater depth. In Norway, our team was invited to visit the customer’s equipment installation workshop and valve application site. Through direct discussions with the engineering and procurement teams, we gained a clear understanding of their concerns regarding high-pressure applications, material selection, and delivery schedules. The customer noted, “Dervos has an excellent grasp of our project needs. Your quick response and professional recommendations give us great confidence.” This feedback reflects not only trust in our product quality but also strong recognition of our service capabilities. The team then traveled to Italy for technical discussions with our local partners and visited their valve assembly and testing facilities. Our representatives introduced Dervos’s manufacturing capabilities, quality inspection processes, and ongoing product enhancements across ball valves, gate valves, butterfly valves, and check valves. The Italian customer remarked, “The solutions you presented are highly practical and will significantly improve the reliability of our projects.” Such positive feedback further strengthened the confidence in our partnership. Through this trip, Dervos gained deeper insights into the European market’s expectations regarding valve performance, quality control, and delivery reliability. We will continue to refine our products and services based on customer feedback, ensuring that every partner receives a reliable and fully tailored one-stop valve solution. Looking ahead, Dervos Valve will remain committed to our service philosophy of listening to customers, responding quickly, and delivering real value. With higher product standards and more professional technical support, we aim to strengthen and advance our cooperation with customers around the world.
DN200 PN16 Bellow Seal Globe valve is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.4408. It has the structural characteristics of body cover bolt, rising pole bracket, angle type, corrugated pipe seal and structural length of 255mm. Its connection mode is RF. And it has hand wheel operation mode.
Payment:
30% when order confirmed, 70% before shipmentProduct Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai, ChinaLead Time:
30~60 days Ex Works after order confirmationMaterial:
EN 10213 1.4408Method of Operation:
Hand Wheel
|
Type |
Bellow Seal Globe Valve |
|
Size |
DN200 |
|
Pressure |
PN16 |
|
Connection |
RF |
|
Operation |
Hand Wheel |
|
Body Material |
EN 10213 1.4408 |
|
Design Norm |
BS EN 13709 |
|
Face to Face Dimensions |
Client's Std. |
|
Flange Ends Dimensions |
BS EN 1092-1 B1 |
|
Test & Inspection Code |
BS EN 12266 |
|
Applicable Medium |
Water, Oil and Gas |
1. Adopting a double seal of corrugated tube and packing to prevent medium leakage and ensure zero leakage;
2. Built in guiding structure to avoid excessive expansion and contraction of the corrugated pipe, extending its service life.
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The 1.5 inch 800LB bellow seal globe valve is designed with outside screw and yoke, handwheel operation, sw end. The reduced port globe valve is has forged steel A105N body. Design Feature 1.Outside screw and yoke 2.Rising stem 3.Bolted bonnet design 4.Bellow seal packing for reliable stem sealing 5.Reduced bore design 6.Handwheel Operated Quick Detail Type Globe Valve Size 1.5'' Design Pressure Class 800 Structure BB, OS&Y, Reduced Port, Bellow Seal Packing Connection Type Socket Weld Operation Handwheel Design Code API 602 End to End ASME B16.10 Connection End ASME B16.11 Pressure & Temperature ASME B16.34 Test & Inspection Standard API 598 Body Material Forged Steel ASTM A105 Trim Material Trim 8 Applicable Temperature -29℃~+425℃ Application W.O.G Origin China Related Knowledge What is a bellw seal valve? For bellow seal globe valves, the lower end bellows is welded on the valve stem to prevent the process fluid from eroding the valve stem. The other end is placed between the valve body and the valve cover to form a static seal. The double seal design ensure that if bellow seal pakcing fails, the stem packing will also function. The bellow seal globe valves are applicable for media like steam, flammable, explosive, heat transfer oil, high purity, and toxic media etc. Special Tests Besides general tests we will do (hydraulic and air test), we could also do tensile strength test, metallographic test, fugitive emission test, and NDE test (UT,RT,PT,MT) upon customers’ specific requests.
Dervos bellow seal globe valve is designed as per EN13709 with face to face dimesnsion per EN558. The special designed bellow seal make sure zero leakage from stem. Quick Detail Type Globe Valve Norminal Size DN 65 NorminalPressure PN 40 Construction Bolted Bonnet, Rising Stem, Bellow Sealed ConnectionType RF Flange Operation Handwheel Design Code EN13709 Face to Face EN 558 Connection EN1092 Test & Inspection EN12266 Body Material Carbon Steel 1.0619 Bellow Material SS304, SS316, SS316L and etc ApplicableTemp -29℃~+420℃ Application Water, Oil, Gas Structure Feature 1. Standard design of double-wall bellow seal 2. Heat-dissipating bonnet design; 3. With lubricant storage device; 4, With design of circlip to fix stem nut; 5. Reasonable product structure, reliable sealing performance and good appearance; 6. The sealing surface is welded with Co-based hard alloy, which has good wear resistance, corrosion resistance, anti-friction performance and long service life; 7. Stem has nitriding treatment with good corrosion resistance and anti-friction performance; 8. With position indicator for stem movement;
The bellows seal globe valve adopts the bellows seal design, which completely eliminates the shortcomings of the normal valve stem packing seal aging and easy to leak, not only improves the energy efficiency, increases the safety of the production equipment, reduces the maintenance cost and frequent maintenance. It also provides a clean and safe working environment.Its simple structure and the low price makes it almost no "competitors". Quick Detail Type Globe Valve Norminal Size 1.5 Inch NorminalPressure 150LB Construction Bolted Bonnet, Outside Screw & Yoke, Rising Stem, Bellow Seal ConnectionType RF Flange Operation Handwheel Design Code ASME B16.34, API 602 Face to Face ASME B16.10 Flange End ASME B16.5 Test & Inspection API 598 Body Material ASTM A105 ApplicableTemp -29℃~+425℃ Application Water, Oil, Gas Structure Feature 1. Double seal design (corrugated pipe + packing). If the bellows fails, the stem packing will also be avoided; 2. External leakage, and in line with international sealing standards; 3. No fluid loss, reduce energy loss, and improve plant equipment safety; 4. Long service life, reduce the number of maintenance, reduce operating costs; 5. Rugged bellows seal design, ensuring zero leakage of the valve stem, providing maintenance-free conditions. Technical Drawing Dimension Our Service Dervos customer service is one of our biggest competitive advantages. In Dervos, we provide- 1.Quotation within 24 hours or no later than 3 days This will let you meet the quotation submission deadline and enhance your working efficiency 2.Weekly status report of your order In this way, you will have a clear picture of your order. You do not need to waste time on pushing us for status update 3.An 18-month warranty period A warranty certificate will issued after shipment and you will not have any concern after buying valves. 4.Solutions to complaints within 3 days Quick and responsible actions to complaints will protect your reputation and reduce the financial loss as much as possible.
The refinery of MOL, located in Hungary, requires regular ball valve and check valve replacements to maintain optimal performance. As a trusted check and ball valve supplier of MOL, DERVOS continues to provide ball valves for their operations. In this project, DERVOS supplied a batch of high-performance ball valves and check valves for fluid control in oil and gas applications. They required various types and specifications of ball and check to meet the operational and sealing requirements of different pipeline systems.
DN32 PN16 Y type strainer is made according to EN12516-1 standard. The valve body is made of WCB. It has the structural characteristics of pressure Y type. Its connection mode is RF.
The DN80 PN16 cast iron gate valve has face to face dimension as per DIN3202 F4 or DIN3202 F5. This GG25 gate valve is designed with resilient seat, non rising stem, bb, RF flange, suitable for water treatment application. Quick Detail Type Gate Valve Nominal Diameter DN 80 Nominal Pressure PN 16 ConstructionType Non-rising stem, Bolted Bonnet, Resilient Seat ConnectionType Flanged OperationType Handwheel Operation Body Material Cast Iron GG25 TrimMaterial Cast Iron Wedge, SS420 Stem, EPDM Seat Design Code DIN 3352 End to End Code DIN 3202 Flange Dimesion DIN 2501 Medium Water Origin China Design Feature 1.Resilient seat for good sealing performance 2.Low flow resistance and small pressure drop 3.Non-rising stem for installation space is limited 4.No limitation for flow direction of medium 5.Epoxy painting available for internal and external part of the valve for anti corrosive function Company Brief Introduction Specializing in valve industry over 10 years, Dervos becomes the leading vendor of gate, globe, check, ball, butterfly, plug valves and strainers. We serve oil and gas user such as LUKOIL, MOL, YPF with local partners. Dervos show its advantages in: 1. Our partnerships with tens of stable suppliers allow us to provide customers with a wide range of high-quality products at a competitive price. 2. Each order is under strict quality control with inspection reports before delivery. 3. We value delivery time as much as our customers do. With the powerful purchasing system, we follow each order closely to secure on-time delivery. 4. One-stop solutions will be offered in a timely manner
3" 150LB Swing Check Valve is made according to API 6D standard. The valve body is made of A216 WCB. It has the structural characteristics of Bolted Bonnet, Swing Type. Its connection mode is RF.
The 6 inch Wafer check valve is made in strict accordance to API 594. The body material LCC make sure the lug type valve is capable to handle harsh environment, and the INCONEL-X 750 spring promise the valve a long service life.
China Welded Bonnet Gate Valve Producer Fabricates Reduced Bore Forged Steel Gate Valve, A105N, 1/2-4 Inch, 150-1500 LB, Welded Bonnet, Integral Flanged.
The valves are widely used in electric power, petroleum chemical industry, metallurgy, Marine, oil, natural gas, coal gas, pharmaceutical and other industries.
3” 150LB Dual Plate Wafer Type Check Valve is made according to API 594 standard. The valve body is made of A351 CF8M+STL. It has the structural characteristics of Dual Plate. Its connection mode is Wafer Type.
1 1/2" 600LB floating ball valve is made according to API 6D standard. The valve body is made of A350-LF2. It has the structural characteristics of floating ball, full bore, split type, anti-fire, anti-static, and anti-flying valve stem design. Its connection mode is RF (125 AARH).
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