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.
The 1 1/2inch 1500LBglobe valve,made of A105N are best suited for throttling application at high pressure and temperature.
Payment:
30% when order confirmed, 70% before shipmentProduct Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai, ChinaLead Time:
30~60 days Ex Works after order confirmationMaterial:
A105NMethod of Operation:
HandwheelQuick Detail
|
Type |
Globe Valve |
|
Nominal Diameter |
1 1/2 Inch |
|
Nominal Pressure |
1500LB |
|
Construction |
Pressure Seal Bonnet |
|
Connection |
SW |
|
Design & Manufacture |
B16.34 |
|
SW Dimension |
ASME B16.11 |
|
Test & Inspection |
API598 |
|
Body Material |
A105N |
|
Disc Material |
304+STL |
|
Temp. Range |
-29～38°C |
|
Media |
Oil, Gas |
Features
·Proven pressure seal design.
·Body guided disc eliminates side thrust and provides longer disc, seat and body life.
·Body made of superior strength forgings and optional cast steel.
·Optional live-loading of packing.
·Other sizes and pressure classes available.
Technical Drawing
Dimension Check
Witness Tests
Our Service
A good customer service is as valuable as product itself. In Dervos, we will offer a full range of customer service to make you feel easy when doing business with us.
Providing weekly production report
When production begins, you will get production report weekly, so that you can have good command of product status and report to your customer at the meantime.
Offering warranty of 18 months
18 months warranty period will be offered after shipment, no concern to purchase valve from Dervos.
Providing solutions within 3-days for complaints
All the complaints will be solved within 3 days, in this case, you can timely reply and solve problems for your customer, to relax them even when complaints happening.
If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.
The 6 Inch PSB globe valve has 1500LB design pressure, butt weld end, and gearbox. The full bore globe valve is made of carbon steel WCB body and trim 5 material. Quick Detail Type Globe Valve Size 6'' Design Pressure Class 1500 Construction Pressure Seal Bonnet, Plug Type Disc, Rising Stem Connection Type Butt Weld Operation Type Bevel Gearbox Opearted Design Code BS 1873 End to End ASME B16.10 Connection End ASME B16.25 Pressure & Temperature ASME B16.34 Test & Inspection Standard API 598 Body Material Cast Steel WCB Trim Material Trim NO. 5 Temperature Range -29℃~+425℃ Application WOG Origin China Material & Dimension NPS DN Class 2 2 1/2 3 4 6 8 50 65 80 100 150 200 L(RF) L1(BW) 900LB 368 419 381 457 610 737 1500LB 368 419 470 546 705 832 2500LB 451 508 578 673 917 1022 L2(RTJ) 900LB 371 422 384 460 613 740 1500LB 371 422 473 549 711 841 2500LB 454 514 584 683 927 1038 H(Opne) 900LB 550 605 678 798 930 1230 1500LB 550 605 866 956 1260 1263 2500LB 560 720 755 1230 1791 2086 W 900LB 350 350 400 450 458 610* 1500LB 400 400 450 560 610* 610* 2500LB 400 450 560 310* 610* 760 Weight (RF) 900LB 78 108 102 142 400 960 1500LB 85 110 135 230 660 1590 2500LB 140 168 247 620 1500 3200 Weight (BW) 900LB 66 91 87 128 355 868 1500LB 77 101 122 209 595 1440 2500LB 100 118 180 438 1148 2594 *Manual gear operator is recommended No Part Name Carbon steel to ASTM Alloy steel to ASTM Stainless steel to ASTM WCB WC6 WC9 C5 CF8 CF8M CF3 CF3M 1 Body A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Seat Ring A105 A182 F11 A182 F22 A182 F5 A182 F304 A182 F316 A182 F304L A182 F316L 3 Disc A105 A182 F11 A182 F22 A182 F5 A182 F304 A182 F316 A182 F304L A182 F316L 4 Stem A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 5 Disc nut A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 6 Cap SS Spiral Wound graphite or SS Spiral Wound PTFE 7 Body Seal Flexible Graphite+316 8 Adjustment Gasket F6 F6 F316 9 Stem packing Flexible Graphite+316 10 Gland Nut A194 2H A194 8 11 Gland Eyebolt A193 B7 A193 B8 12 Pin Carbon steel or Stainless Steel 13 Cap Nut Carbon steel or Stainless Steel 14 Gland A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 15 Gland Flange A216 WCB A351 CF8 16 Yoke A216 WCB A351 CF8 17 Stem Nut A439 D2 or B148-952A 18 Screw Carbon steel 19 Handwheel Ductile Iron or carbon steel 20 Name Plate Stainless steel or Aluminum 21 Washer Carbon steel 22 Nut Carbon steel or Stainless Steel Related Knowledge Why do we use pressure seal bonnet? Pressure sealed bonnet are often used for valves with high design pressure. The higher the internal pressure gets, the greater the sealing force beween body and bonnet become. For bolted bonnet valves, the body and bonnet are joined by studs and nuts with a gasket between the flange faces to facilitate sealing. However,as system pressure increases,the potential for leakage through the body and bonnet increases. But for pressure sealed valve, “bonnet take-up bolts” to pull the bonnet up and seal against the pressure seal gasket. That is why when pressure increase, the performance of pressure seal gasket between body and bonnet becomes better.
The 1 1/2inch 1500LB globe valve,made of one kind of alloy steel F22, is the best answer to working conditions under high pressure and temperature .
The Class 1500 4'' cryogenic ball valve is designed with extended stem for low temperature application. The valve is made of LF2 with fully welded body, butt weld end and gearbox operation. Design Feature-Fully welded & forged body-Extended stem or bonnet-Full port design and piggable-Anti blow-out stem-Antistatic function- Automatic cavity relief-Bi-directional seat and DBB design-With stem and seat grease fittings Quick Detail Type Ball Valve Size 4" Pressure ANSI 1500 Construction One-Piece Body, Fully Weld, Extended Stem or Bonnet, Full Port Connection Butt Weld Operation Gearbox Operated Body Material Low Temperature Steel A350 LF2 Design Code API 6D Pressure & Temp ASME B16.34 End to End Dimension ASME B16.10 End Connection ASME B16.25 Inspection API 598 Temperature Range -46℃~+200℃ Media Oil, Water, Gas Related KnowledgeWhat is the difference between full bore and reduced bore ball valve?The internal diameter of a full bore ball valve is the same as the inner diameter of the pipe. The full bore ball valve has little resistance and pressure drop to the flow. Plus, the full bore ball valve is piggable.However, the internal diameter of a reduced port (standard port) ball valve is smaller than the inner pipe size. Flow restriction caused by the reduced port will cause a pressure drop. And sometimes a pig to clean the pipe will get stuck in the reduced port ball valve.
The 16 inch cast steel gate valve with gearbox and 600LB RF flange is designed as per API 600. The bolted bonnet gate valve features in rising stem, resilient wedge and metal seat. Quick Detail Type Gate Valve Size 16" Pressure Class600 Construction Bolted Bonnet, Rising Stem, OS&Y, Flexible Wedge, Metal Seat Connection RF Flange Operation Gearbox Design Code API 600 Face to Face ASME B16.10 Flange End ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB TrimMaterial Trim 5 Temperature Range -29℃~+425℃ Medium Water, Oil and Gas Origin China Dimension & Material Class 600 NPS in 2 2 1/2 3 4 6 8 10 12 14 16 18 20 24 DN mm 50 65 80 100 150 200 250 300 350 400 450 500 600 L-L1 (RF-BW) in 11.5 13 14 17 22 26 31 33 35 39 43 47 55 mm 292 330 356 432 559 660 787 838 889 991 1092 1194 1397 L2 (RTJ) in 11.625 13.125 14.125 17.125 22.125 26.125 31.125 33.125 35.125 39.125 43.125 47.25 55.375 mm 295 333 359 435 562 664 791 841 892 994 1095 1200 1407 H (OPEN) in 18.625 21.75 23.375 28 1/16 38 3/16 44 3/16 52.375 59 13/16 68.125 72.25 90.125 98 13/16 119 mm 474 553 593 713 970 1122 1330 1519 1730 1835 2290 2510 3022 W in 9.875 9.875 11 13/16 13.75 19 11/16 22 1/16 28.375 24 24 24 24 30 30 mm 250 250 300 350 500 560 720 610* 610* 610* 610* 760* 760* WT (kg) RF 41 58 88 131 253 413 623 784 1288 1820 2150 2540 4080 BW 35 50 68 104 208 328 496 637 1120 1448 1828 2201 3360 *Manual gear operator is recommended No Part Name Carbon steel to ASTM Alloy steel to ASTM Stainless steel to ASTM WCB LCB WC6 WC9 C5 CF8 CF8M CF3 CF3M 1 Body A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Seat Ring A105 A350 LF2 A182 F11 A182 F22 A182 F5 A182 F304 A182 F316 A182 F304L A182 F316L 3 Wedge A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 4 Stem A182 F6 A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 5 Bonnet nut A194 2H A194 4 A194 7 A194 8 6 Bonnet bolt A193 B7 A320 L7 A193 B16 A193 B8 7 Gasket SS Spiral Wound graphite or SS Spiral Wound PTFE 8 Bonnet A216 WCB A352 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 9 Backseat bushing A182 F6 A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 10 Stem packing Graphite or PTFE 11 Lantern A182 F6 A182 F6 A182 F304 A182 F304 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 12 Gland Nut A194 2H A194 8 13 Gland Eyebolt A193 B7 A193 B8 14 PIN Carbon steel or Stainless Steel 15 Gland A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 16 Gland Flange A216 WCB A351 CF8 17 Stem Nut A439 D2 or B148-952A 18 Nipple Carbon steel or Stainless Steel 19 Retaining Nut Carbon steel 20 Hand Wheel Ductile Iron or carbon steel 21 Name Plate Stainless steel or Aluminum 22 H.W.Lock Nut Carbon steel
DN15 PN63 Forged Steel Globe Valve is made according to BS 5352 standard. The valve body is made of A105N+STL. It has the structural characteristics of through way type, bolt bonnet and structural length of 130mm. Its connection mode is EN1092-1 B. And it has hand wheel operation mode.
16'' 150LB swing check valve is made according to API 594 standard. The valve body is made of A216 WCB+316. It has the structural characteristics of swing type and double disc wafer type. Its connection mode is RF.
The dual disc wafer check valve is designed as per API 594 and tested per API 598. The bronze non return valve is applicable for sea water. Quick Detail Type Check Valve Size 6'' DesignPressure Class 150 Construction Dual Plate Type, With Retainer Connection Wafer Type Design & Manufacture API 594 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material Aluminum Bronze C95800 Trim Material Aluminum Bronze C95800 Media W.O.G. Dervos Inspection after Valve Assembly Valve quality is one of perspectives we care about most. In Dervos, quality control starts from raw material, machining, assembly to pre-shipment inspection. After assembly, the quality checking team will do visual checking, dimension checking, hydraulic testing and air testing. Every order must pass the test per inspection standards. Otherwise our quality checking team will not release the shipment. Inspection Reports Documents can be used to prove how we control valve quality. Along with every order, Dervos will provide clients with an inspection report & a 3.1 mill test report for free. In Dervos inspection report, you will see the actual results of dimension checking and pressure testing along with painting and packing picture. All these info are shown through data and clear pictures. In 3.1 mill test report, we will show you the chemical composition, mechanical property and heat number for valve body, bonnet, stem, disc and so on.
The lug type knife gate valve is designed per MSS-SP-81.Made by stainless steel CF8, the 4 inch gate valve has 150 LB flange connection and handwheel operation.
1/2" 6000PSI needle valve is made according to ASME B16.34 standard. The valve body is made of SS316. It has the structural characteristics of straight through. Its connection mode is FNPT. And it has lever operation mode.
4” 125LB Y Type Strainer is made according to ASME B16.34 standard. The valve body is made of Ductile Iron A395. It has the structural characteristics of Y-Type, Body-Bonnet Bolted Connection. Its connection mode is FF.
The DN100 safety valve, made of WCB and according to GB/T12241-2005, usually work as the over-pressure protection device that work under a steam, air, water or other non-corrosive medium.
6"X4" 90LB ball valve is made according to ASME B16.34 standard. The valve body is made of A105. It has the structural characteristics of reduced diameter, fixed ball, DIB-1, fireproof, anti-static, 3-piece. Its connection mode is RTJ. And it has worm wheel operation mode.
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