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Business Team Visits Europe for In-Depth Customer Engagement
Business Team Visits Europe for In-Depth Customer Engagement
2025-11-20

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.

Maintenance Tips to Extend the Service Life of Butterfly Valves
Maintenance Tips to Extend the Service Life of Butterfly Valves
2025-11-14

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 ...

Check Valve Maintenance: When to Replace and How to Fix Common Issues
Check Valve Maintenance: When to Replace and How to Fix Common Issues
2025-11-06

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 ...

ball valve and check valve replacement
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DERVOS Valves Applied in MOL Refinery Upgrade Project in Hungarian

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.

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Product Detail

DERVOS Valves Applied in MOL Refinery Upgrade Project in Hungarian


Trunnion Mounted Ball Valves (112 units)

· Size: DN80-DN400

· Pressure: PN16-PN63

· Features: Full flow ball valve design, DBB double block and bleed structure, PMSS seal (primary metal + secondary soft seal), anti-blowout stem, IP68 waterproof turbine operation. 


Floating Ball Valves (71 units) 

· Size: DN20-DN25

· Pressure: PN25-PN63

· Features: Floating ball design, handle operation, suitable for small and medium-sized pipelines.


Swing Check Valve (9 units) 

· Size: DN50-DN300

· Pressure: PN25-PN63

· Features: Swing type, simple structure and low flow resistance, suitable for large flow and low-velocity conditions.


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fixed ball valves were customized with 2-meter extended valve stems

Customized Solution


In this project, 4 units fixed ball valves were customized with 2-meter extended valve stems and turbines oriented toward the operating platform.


This design ensures operators can safely and efficiently operate and maintain the valves from a distance, fully addressing the site’s needs.


The custom solution showcases DERVOS’s flexibility in meeting customer requirements and engineering expertise.



Customer Feedback


The end user, MOL, highly recognized the quality and performance of the valves, noting the excellent painting for its durability. They praised DERVOS products as reliable, safe, and fully meeting the project’s requirements.


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Related Products
ECOFUEL Turns Waste into Diesel with DERVOS Valve Solutions
ECOFUEL Turns Waste into Diesel with DERVOS Valve Solutions

In 2017, DERVOS contributed to an innovative environmental initiative led by ECOFUEL, an emerging canadian player in clean technology. This groundbreaking project aimed to produce sustainable diesel from solid waste, setting a precedent in green energy solutions. DERVOS is proud to have provided 136 sets of premium valves to support this pioneering effort.

Dervos Valve Supply for Refinery in Hungary
Dervos Valve Supply for Refinery in Hungary

Project Background   In 2024, DervosValve was selected as a trusted valve supplier for a refinery project in Hungary. The client required large-sized industrial valves capable of handling complex and high-pressure oil and gas media. With years of engineering experience and proven track records in the energy sector, Dervos was chosen to provide a complete valve solution tailored to the refinery’s operational needs.     Scope of Supply   ● 10 pcs Gate Valves ● 9 pcs Check Valves   All valves were designed and manufactured according to API and ASME standards, ensuring compliance with international refinery safety and performance requirements.     Product Design & Technical Highlights   The supplied valves feature bolted bonnet design, flexible wedge, and rising stem with yoke support, which enhance sealing reliability and facilitate maintenance. Their large-scale structure was customized to fit the refinery’s pipeline system, allowing smooth fluid control and stable operation under high temperature and pressure.     Performance in Refinery Conditions   Refinery environments involve frequent temperature fluctuations and medium impurities. Dervos valves demonstrated outstanding sealing performance, corrosion resistance, and mechanical strength, ensuring long-term stability with minimal maintenance requirements. The bolted bonnet design also makes disassembly and inspection more convenient during scheduled shutdowns.   Why the Client Chose Dervos   The Hungarian client valued Dervos for: ● Proven experience in oil & gas valve solutions ● Strict material traceability and quality control system ● Flexible customization capabilities for large valve dimensions ● On-time delivery and complete documentation support   Throughout the project, our technical and logistics teams worked closely with the client’s engineers, ensuring each valve was tested, packaged, and delivered to meet project timelines and refinery installation standards.   Customer Feedback & Project Outcome   After installation and commissioning, the refinery reported stable operation and precise flow control performance. The valves’ large design and robust construction fully met system pressure and flow requirements. The client expressed satisfaction with both the quality and Dervos’ technical responsiveness, laying a solid foundation for future cooperation.   Conclusion   This successful refinery project in Hungary once again highlights Dervos’ ability to deliver reliable, large-size valve solutions for the oil and gas industry. We continue to serve our global partners with precision engineering, professional service, and long-term reliability.

2500LB High Pressure Non Return Valve
Pressure Seal Tilting Disc Check Valve 12 Inch 2500LB

The 12 inch high pressure check valve is designed with pressure seal bonnet, RTJ flange, tilting disc, made of carbon steel WCB body and hard face sealing. Quick Detail Type Check Valve Size 12'' DesignPressure 2500LB Construction Pressure Seal Bonnet, Tilting Disc Type Connection RTJ Flange Design & Manufacture ASME B16.34 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB Trim Material 13CR+STL Temp Range -29℃~+350℃ Media W.O.G. Product Range Body Material Range: WCB, WCC, WC1,CF8M, CF8, CF3, CF3M, LCB, LCC Size Range: 2”~60” (DN50~DN1500) End Connection Type: Flange End, Weld End Design Pressure Range: 150lbs~600lbs  Temp Range: -46℃~ +425℃ Related Knowledge What is a tilting disc check valve? The disc of a tilting disc check valve has a pivot point at the center of it. It is desinged to overcome weaknesses of general type swing check valve. Compared to swing type check valve, the tilting check valve could remain fully open and steady at lower flow rates. That is to say, the swing check valve needs a high velocity of fluid to keep disc open and a higher cracking pressure. For low pressure situation, the pressure drop of a tilting disc check valve is much lower than the swing type. But at a higher flow rate, the tilting check valve has higher pressure drop than swing type.

Steam Trap Valve
DN15 PN40 Bimetal Steam Trap Valve A105 RF GB/T22654

DN15 PN40 steam trap valve is made according to GB/T22654-2008° standard. The valve body is made of A105. It has the structural characteristics of bimetal type and BK47-Y model. Its connection mode is RF.

Lift Check Valve
A105N API602 2" 800LB Lift Check Valve SW

2" 800LB lift check valve is made according to API 602 standard. The valve body is made of ASTM A105N+STL. It has the structural characteristics of lift type. Its connection mode is SW.

1/2 Inch NPT Needle Valve
Stainless Steel Needle Valve 1/2 Inch 6000 PSI NPT

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.  

Globe Valve
DN25 PN63 Forged Steel Globe Valve BS5352 Handwheel A105N SS304

DN25 PN63 globe valve is made according to BS5352 standard. The valve body is made of A105N+SS304. It has the structural characteristics of bolt cover, straight through type. Its connection mode is EN1092-1 D. And it has hand wheel operation mode.

Eccentric Butterfly Valve
EN593, DN800 PN25 Double Eccentric Butterfly Valve, RF Connection, Body WCB

DN800 PN25 double eccentric butterfly valve is made according to EN593 standard. The valve body is made of ASTM A216 WCB + Internal Epoxy Coating. It has the structural characteristics of double eccentricity, unidirectional and structural length of 200mm. Its connection mode is double flange RF EN1092-1.

Double Eccentric Butterfly Valve
Double Offset Cast Iron Butterfly Valve EN593 PN10 DN500

The cast iron butterfly valve belongs to double offset type. also is soft seal butterfly valve,It owns a compact body, low torque value, and perfect sealing function, suited for water application with normal temperature range.  Quick Detail Type Butterfly Valve Nominal Size DN500 Nominal Pressure PN10 Structure Double Offset, Soft Seated Connection Type Flange Type Operation Gear Operated Design Code EN 593 Face to Face EN 558 End Connection EN 1092 Test & Inspection EN 12266 Body Material Cast Iron GGG50 Temperature Range -15℃~+150℃ Application Water, Oil, Gas Dimension Checking & Pressure Testing Tag & Packing

Top Entry Ball Valve WCB Gearbox
High Pressure Top Entry Ball Valve 16 Inch 900LB

The top entry full port ball valve with drain, vent and sealant injection is designed as per API 6D. The high pressure ball valve has Class 900 raised face flange and gearbox. Quick Detail Type Ball Valve Size 16" Pressure ANSI 900 Construction 1 Piece Body, Top Entry, Bolted Bonnet Connection Flanged End Operation Mode Gearbox Body Material A216 WCB Design & Manufacture API 6D Pressure & Temp Code ASME B16.34 End to End ASME B16.10 End Connection ASME B16.5 Inspection API 6D, API 598 Temperature Range -29℃~+200℃ Medium Oil, Water, Gas Related Knowledge What is a top entry ball valve and its advantage? A top entry ball valve is the valve which we assemble from the top side. It has a one single piece body. The less thread connection on the valve body means less weight and leakage paths. Plus, we could have access to the ball part without removing it from the pipeline. The top entry ball valves are often used in the pipeline with less maintenance for internal parts. Inspection Reports For each order, Dervos will provide inspection reports to show you the whole inspection process and results. Plus, we will provide material report to let you know that the material we provide is as per standards.

Plug Valves For Natural Gas Service
Three Way Plug Valve Wrench 4 Inch 150LB RF Flanged

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.

Trunnion Mounted Ball Valve
API 6D, DN400 PN25 Trunnion Mounted Ball Valve, EN 1092-1 B1, Body LF2

DN400 PN25 trunnion mounted ball valve is made according to API 6D standard. The valve body is made of A350 LF2. It has the structural characteristics of fixed ball, full flow, DBB double row double plug, PMSS seal (primary metal seal+secondary soft seal), with discharge function in the on/off position, anti-flying valve stem, double O-ring at the top of the valve stem, valve seat: dual piston effect. Its connection mode is EN 1092-1 B1. And it has IP68 waterproof turbine operation mode.

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    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.

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