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.
Product Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai ChinaLead Time:
30~55 days Ex Works After Order ConfirmationMaterial:
Cast Steel Globe ValveMethod of Operation:
HandwheelDervos 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;
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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.
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.
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.
The 8 inch plug valve is designed per API 6D with Class 150 RF flange and gearbox operation. The inverted plug valve is made of LCB. Dervos could offer customizing service by providing clients with valves in different sizes, materials, standards, design pressure, structure, operation type and connection type. Quick Detail Type Plug Valve Size 8'' Design Pressure 600LB Construction Inverted Type, Lubricated Type, Pressure Balanced Connection RF Flange Operation Gearbox Design Code API 6D Face to Face ANSI B16.10 End Connection ANSI B16.5 Test & Inspection API 598 Body Material LCB Temperature Range -46℃~+425℃ Application Water, Oil and Gas Dimension
1" 1000PSI floating ball valve is made according to API 608 standard. The valve body is made of A182 F316. It has the structural characteristics of 2-piece and floating ball type. Its connection mode is NPT (ASME B1.20.1). And it has lever operation mode.
The double offset high performance butterfly valve, with lever operation and lug body, is designed per API 609. The CF8M body and PTFE seat butterfly valve is more durable in serving the application. Quick Detail Type Butterfly Valve Size 3'' Design Pressure 150LB Construction Double Eccnetric, Soft Seat Connection Type Lug Operation Wrench Operated Design Code API 609 Face to Face ASMEB16.10 End Connection ASMEB16.5 Test & Inspection API 598 Body Material Stainless Steel CF8M Temperature Range -29℃~+150℃ Application Water, Oil, Gas Dimension Class 150 DN mm 40 50 65 80 100 125 150 200 250 300 350 400 NPS in 1 1/2 2 2 1/2 3 4 5 6 8 10 12 14 16 L mm 127 127 127 127 152 203.2 203.2 203.2 203.2 in 5 5 5 5 6 8 8 8 8 L1 mm 38.1 46 50.8 48 54 63.5 57 63.5 71.5 81 92 101.5 in 1.5 1.81 2 1.88 2.13 2.5 2.25 2.5 2.81 3.19 3.62 4 H mm 185 190 220 229 239 252 284 307 337 392 435 481 in 7328 7.48 8.7 9 9.4 9.9 11.2 12 13.3 15.4 17.1 19 D(W) mm 160 160 160 160 160 160 160 200 200 250 250 300 in 6.3 6.3 6.3 6.3 6.3 6.3 6.3 7.9 7.9 9.8 9.8 11.8 Weight (Kg) mm 12.5 13.5 17 38 72 105 148 182 230 in 8 9 10 10 11 14.5 34.2 66 98 134 168 200 Related Knowledge What is a high performance butterfly valve? A high performance butterfly valve is often designed with double offset and PTFE seat, to handle everything from general applications to viscous and corrosive liquids; corrosive gases and steam. Compared to concentric resilient seat butterfly valve, the disc of the high performance butterfly valve is arranged and positioned off the center of the pipe bore, which could reduce wear and tear to the valve during operation and increase sealing performance. In conlusion, high performance butterfly valve is applicable for higher pressure and temperature applications. Meanwhile, it has longer cycle life and better sealing ability.
DN40 PN40 floating ball valve is made according to EN 13709 standard. The valve body is made of A182 F316L. It has the structural characteristics of floating ball. Its connection mode is RF. And it has lever operation mode.
1" 1500LB gate valve is made according to ASME B16.34 standard. The valve body is made of A350 LF2. It has the structural characteristics of three piece, floating ball, full bore, anti-fireproof, anti-static, and anti-flying valve stem design. Its connection mode is RTJ. And it has lever operation mode.
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.
The 6 inch 600LB globe valve, made of ASTM216 WCB, is designed as per API623. It is operated by a handwheel and is connected with pipeline by RF. The disc of the globe valve contain 13Cr, therefore this valve enjoys a better ability to resist corrosion.
The 3 way plug valve is made of WCB body and stainless steel trim as per API 599. The plug valve that could connect any two ports together is applicable for natural gas service, water, oil and so on. Quick Detail Type Plug Valve Size 4'' DesignPressure 150LB Construction Three Way Type Plug Valve ConnectionType Flange Connection Operation Lever/Wrench Design Code API 599 Face to Face ASME B16.10 End Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB TemperatureRange -29℃~+425℃ Application WOG Related Knowledge What are types of plug valves? Lubricated Plug Valve The plug gets lubricated by injecting sealant through injection fitting. The lubricant make sure the smooth movement and prevent the corrosion of plug. Usually, the seat of lubricated plug valve is metal, thus they can withstand higher temperature, available in larger size and higher pressure. Non-Lubricated Plug Valve A non-metallic sleeve or liner is installed in the body cavity of the plug valve. This sleeve reduce the fricion beween plug and body. Meanwhile it prevents the corrosion of plug. Due to non-metallice sleeve, the non-lubricated plug valve cannot be used in high temperature condition. Multiway Plug Valve The multiway plug valve is used for diverting flow in transfer lines. The multiway plug valves we often see are 3 way plug valve or 4 way plug valve. Dervos Packaging Based on sufficient experience, we have developed complete packing specifications and procedures to ensure clear and safe transportation so that you can receive good and sound products. And this is also an important factor that we earn good reputation from our customers.
4" 150LB butterfly valve is made according to API 609 standard. The valve body is made of A216 WCB. It has the structural characteristics of center line. Its connection mode is lug (UNC threaded hole, RF 125-250AARH). And it has lever (locking device) operation mode.
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