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.
Butterfly valves are widely used as regulating and shut-off devices in industrial piping systems, valued for their simple structure, lightweight design, and rapid open-close operation. They find applications across water treatment, chemical, metallurgical, power, oil, and gas industries. However, even high-quality butterfly valves can experience performance degradation if proper maintenance is neglected over long-term operation.This article explores the structural features, common issues, and maintenance practices to help effectively extend the service life of butterfly valves. 1. Understanding the Operational Characteristics of Butterfly Valves A butterfly valve primarily consists of a valve body, disc, stem, sealing elements, and an actuator. Its operation relies on the rotation of the disc, driven by the stem, to control fluid flow. During operation, the disc remains immersed in the fluid, subject to erosion, corrosion, and pressure shocks. Therefore, the valve’s lifespan is closely related to sealing performance, material selection, and the operating environment. 2. Common Factors Affecting Butterfly Valve Lifespan Frequent Operation and High Differential Pressure High-frequency cycling or prolonged operation under high pressure and flow velocity can cause valve seat wear and stem seal aging. Corrosive Media and Sediment Build-Up Chemical fluids or particulate-laden media can corrode the disc and clog sealing surfaces, reducing smooth operation. Improper Installation Misalignment between the valve and pipeline, or uneven bolt tightening, may lead to eccentric disc friction and damage to sealing elements. Lack of Regular Maintenance Neglecting routine cleaning and lubrication can increase operating torque, accelerate seal wear, and shorten the valve’s overall service life. 3. Maintenance Tips to Extend Butterfly Valve Lifespan 1. Proper Installation as the Foundation Ensure the valve body is aligned with the pipeline center to avoid eccentric stress. Use appropriate gaskets between the valve and flange to prevent localized stress. For actuated butterfly valves, confirm correct travel adjustment to avoid exceeding torque limits. 2. Regular Cleaning and Inspection Periodically remove deposits and debris from the disc surface to prevent seal surface damage. Check stem packing and seals; replace immediately if signs of aging are detected. For pipelines carrying particulate-laden media, flush the valve regularly to prevent clogging. 3. Lubrication and Corrosion Protection Apply grease to the stem, bearings, and drive components regularly to maintain smooth operation. For valves operating in seawater or corrosive environments, select corrosion-resistant coatings or materials such as aluminum bronze or duplex stainless steel. 4. Proper Operation and Control Avoid rapid or forced operation to prevent disc deformation from impact. If the ...
A check valve is a critical device that prevents backflow, widely used in water treatment, oil & gas pipelines, chemical processing, and steam systems. After long-term operation, check valves may experience issues such as leakage, vibration noise, or sticking. If not addressed promptly, these problems can reduce system efficiency and even cause equipment damage or safety hazards. So, how can you tell if a check valve needs replacement? Which faults can be repaired, and which require a full replacement? This article provides a systematic guide. 1. Basic Operating Principle of Check Valves The primary function of a check valve is to automatically prevent backflow. When fluid flows in the intended direction, the valve disc is pushed open by pressure; when flow reverses, the disc closes automatically, using either its own weight or a spring, preventing backflow. Common types include: Lift Check Valve Swing Check Valve Dual Plate Wafer Check Valve Ball Check Valve Although their designs vary, the key criteria for determining whether a check valve needs replacement remain the same: sealing performance, operational smoothness, and structural integrity. 2. How to Determine if a Check Valve Needs Replacement Visible Leakage (Internal or External) If fluid continues to flow backward when the valve is closed, it indicates significant wear or deformation of the sealing surfaces, preventing an effective seal. If the leakage exceeds system tolerances and cannot be corrected by cleaning or resurfacing, the valve or its sealing components should be replaced. Sticking or Inflexible Valve Disc After long-term operation, the valve stem, guides, or disc may become stuck due to scaling, corrosion, or debris. If cleaning, descaling, or lubrication fails to restore smooth operation, replacement is recommended. Excessive Noise or Vibration Frequent opening and closing or rapid disc rebound can cause vibration or knocking sounds. This is usually due to spring failure, loose valve components, or worn guides. Persistent or frequent noise should trigger inspection of the valve’s structural integrity and consideration for replacement. Corroded or Cracked Valve Body or Cover Exposure to acidic, alkaline, or high-temperature fluids can corrode or crack the valve body, compromising structural strength and posing safety risks. Such damage cannot be repaired and requires full valve replacement. Frequent Backflow or Abnormal System Pressure Fluctuations Poor sealing or delayed valve response can cause system pressure variations, including water hammer. If repeated adjustments do not resolve the issue, it indicates aging of the internal spring or disc mechanism, necessitating timely replacement. 3. Common Fault Diagnosis and Solutions Fault: Valve fails to close completely, causing backflow Cause: Worn sealing surfaces, deformed disc, or trapped debris Solution: Remove ...
10" 300LB gate valve is made according to API 600 standard. The valve body is made of ASTM A217 C5. It has the structural characteristics of bolt cover, elastic gate, rising stem, OS&Y, full bore and body valve seat. Its connection mode is RF (125~250AARH). And it has bevel gear 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:
ASTM A217 C5Method of Operation:
Bevel GearProduct Description
|
Type |
Gate Valve |
|
Size |
10" |
|
Pressure |
300LB |
|
Connection |
RF (125~250AARH） |
|
Operation |
Bevel Gear |
|
Body Material |
ASTM A217 C5 |
|
Design Norm |
API 600 |
|
Face to Face Dimension |
ASME B16.10 |
|
Flange Dimension |
ASME B16.5 |
|
Test & Inspection Code |
API 598 |
|
Temperature |
-29 ~ 650°C |
|
Applicable Medium |
Water, Oil and Gas |
Features
1. Compact structure, reasonable design, smooth channel, and low flow resistance coefficient;
2. Long service life, widely used in pipelines of various systems in petroleum, chemical, hydraulic, and thermal power plants.
Technical Drawing
Dimension Checking
Pressure Testing
Painting
Packing
Inspection report
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10’’ 300LB gate valve is made according to API 600 standard. The valve body is made of ASTM A217 C5 + STL. It has the structural characteristics of rising stem and bolt cover. The gate valve connected by flange has the operation mode of hand wheel.
6" 150LB gate valve is made according to API 600 standard. The valve body is made of ASTM A217 WC6. It has the structural characteristics of bolt cover, elastic gate, rising stem, OS&Y, full bore, body valve seat. Its connection mode is RF (125~250AARH）. And it has hand wheel operation mode.
2" 600LB Alloy Steel Gate Valve is made according to API 600 standard. The valve body is made of ASTM A217 WC6. It has the structural characteristics of Body cover bolt. Its connection mode is BW SCH 80. And it has Non lifting handwheel operation mode.
3" 300LB Alloy Steel Globe Valve is made according to API623 standard. The valve body is made of A217 WC6. It has the structural characteristics of through way type and structural length of 317.5mm. Its connection mode is RF. And it has hand wheel operation mode.
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.
The 6 inch 150 LB single disc wafer check valve, designed per API 594, has one disc and wafer connection. It will have the best performance under -29 to 350 Celsius degree.
Designed with 800 LB sw end, the 2 inch globe valve features in plug disc, bolted bonnet, and y type structure. The handwheel operated globe valve is made of forged steel body and stainless steel trim. Quick Detail Type Globe Valve Size 2'' Pressure ANSI 800 Structure Y Type, Y Pattern, Bolted Bonnet ConnectionType SW Operation Handwheel Operated Design Code API 602 Face to Face ASME B16.10 Connection Standard ASME B16.11 Pressure & Temperature ASME B16.34 Test & Inspection Standard API 598 Body Material ASTM A105 ApplicableTemperature -29℃~+425℃ Application Water, Oil, Gas Related Knowledge What is the main reason to use Y-pattern globe valve? A Y type globe is designed with 45° between seat and stem. In other words, the flow will remain straight linear from inlet to outlet ports.Compared to staight pattern globe valve, the y pattern globe valve reduce the flow resistance and pressure drop. This kind of y pattern globe valve is well suited for high pressures and severe application. FAQ 1. How long have you been in business and how long have you producing valves? We have been in valve exporting industry for more than 10 years since foundation in 2008. Our business has expanded tremendously to five continents all around the world. 2. What are your main products and their advantages? Our main products include gate, globe, check, ball, butterfly, plug valves and strainers, available in different materials, sizes and pressure, which are widely used in various industries. 3. Does Xiamen Dervos Valves Industry Co., Ltd. make products for other companies? Yes, of course. We have a reference list with customer information like country, product type, order volume and some even with project names.
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.
The 6000 psi high pressure needle valve is made of stainless steel F316 according to ASME B16.34. The 1/2 inch NPT needle is used for regulating the flow of fluid and suitable for application with high pressure and small flow. Quick Detail Type Needle Valve Size 0.5 Inch DesignPressure 6000 PSI ConnectionType Female Thread FNPT Design Code ASME B16.34 End Connection ASME B1.20.1 Face to Face ASME B16.10 Test & Inspection API 598 Body Material SS316 TrimMaterial SS316 Application Water, Oil, Gas Why choose Dervos as your partner?One Stop ServiceHere in Dervos, we can provide you with one stop service by our complete product list, it means, you don’t need to search for various suppliers for different types of valves, and it will surely save your time and energy. All you need to do is choose Dervos and we will provide complete solutions to you. On Time DeliveryDervos keeps a high percentage of on time delivery. Why could we achieve that? Our purchasing team follows the order very closely. Plus, our QC and sales person will also do monitoring job on each order.Strict Quality Control All the members in the QC team are very experienced and professional. For each order, they will check the raw material, manufacturing process, do the pressure testing on shell and seal, and check the valve dimension per assembly drawing. Lastly, they will inspect the painting and packaging.
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 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.
3/4" 800LB forged steel gate valve is made according to API 602 standard. The valve body is made of A105N. It has the structural characteristics of bolt cover, rising stem, OS&Y, reduced diameter. Its connection mode is SW. And it has hand wheel operation mode.
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