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Dervos, Complete Solutions to Industrial Valves
Dervos Profile
DERVOS GROUP, established in 2008 and headquartered in Xiamen, with ball valve and GGC valve factories in Lishui, Zhejiang. With years of industry expertise, we have evolved into a comprehensive valve solutions provider, offering a one-stop solution for production and procurement.   Supported by a dedicated R&D team and factories in Zhejiang, we not only manufacture existing superior products but also engage in independent design and manufacturing to meet customized requirements. To ensure standard production and stable quality, DERVOS actively adopts and strictly adheres to advanced management systems and certificates such as ISO 9001, ISO45001, PED CE, UKCA, API 6D, API607, API624, API6FA, ISO15848, etc.   Simultaneously, DERVOS boasts a professional procurement and sales team committed to providing a one-stop procurement experience. In addition to the production of ball valves and GGC valves from our factories, we promptly respond to and fulfill customers' other product requirements. We maintain solid partnerships with over 100 high-quality valve manufacturers, facilitating rapid sourcing of products that match clients' specifications in terms of both price and quality. Our procurement and quality inspection teams rigorously monitor the production progress and quality inspection of externally sourced products, ensuring product quality and delivery. Meanwhile, the sales team oversees the entire process, ensuring excellent service at every stage of pre-sales, in-sales, and after-sales.   Our product range encompasses nearly all valve types across various industries. We focus on providing diverse services with added value. Having developed for more than a decade, DERVOS has established sales agencies in over 20 countries, distributing products to Europe, South America, and the Middle East. Our sales network spans 5 continents, 28 countries, and includes more than 70 large companies, among them renowned operators such as BP, YPF, SHELL, and PETRONAS.   Supplying suitable, qualified, and reasonably-priced valves for clients worldwide remains our permanent pursuit.  
About Us
Our Products
As a professional exporter and supplier of industrial valves, Dervos has a complete product list, ranges from ball valve, gate valve, globe valve, check valve, butterfly valve, plug valve, strainers to needle valve, diaphragm valve, control valve, safety valve and so on. We offer customization service to meet clients' requirements on valve sizes, pressure ratings, materials, connection types, operations and structure design.
All Product
Our Certificates
EAC
EAC
UKCA
API6D
API 607
API 6FA
API624
PED CE
ISO 9001
ISO 15848-1 1-8
ISO 15848-1 1-4
ISO45001:2018
ISO9001, ISO14001, OHSAS18001, PED/CE,API 607, TS, API 6FA, WRAS 4AD2000W0, DNV-GL and etc are all available in Dervos upon clients' requests
Hot Products
With a supplier list of over 500 China valve manufacturers, Dervos could always find right products for our customers in an efficient way. Forged steel ball valve, cast steel ball valve, fully welded ball valve, flexible wedge gate valve, wafer check valve, swing check valve, concentric butterfly valve, bellow seal globe valve and etc are all in our hot product range.
Comments

"Everything is perfectly made. We are grateful for the confidence you are showing in our organization and fully trust our hard-work will be fruitful for both of our companies.  You are truly a GEM for Dervos Valves. Our best compliments to you!"

"Your customer service is outstanding.    ... ...  The check valves works fine and the customer service certainly makes up for it.    ... ...  The customer service couldn’t be better."

"We are very satisfied with all your kind business supports. You are always kindly answering all our questions. So, we thank you for all your efforts. When we have any new project, we will readily make a contact with you!"

"I’ve received your document today. Thank you so much.  Our engineer says your report seems to have been done quite well, he appreciated, of course we haven’t got the vannes so we haven’t had a check, but I believe there won’t be problem, hope so."

"Thank you for engaging with our organisation regarding Dervos. We place various orders with Dervos and products were always completed ex-factory, to drawing and within the time periods indicated. Dervos is a very proud company and place huge emphasis in delivering quality products to their customers."

UAE
UAE
Industry Knowledge
  • Three Common Causes of Valve Leakage and Emergency Remedies
    Three Common Causes of Valve Leakage and Emergency Remedies
    2025-05-28

    In industrial production, valves are critical components for fluid control, and their sealing performance directly impacts system safety and stability. Leakage not only reduces operational efficiency but may also lead to fluid escape, posing serious safety risks. This article outlines three common causes of valve leakage and provides corresponding emergency response recommendations to help you quickly identify issues, take action, and mitigate risks.   1. Seal Surface Wear or Damage   Cause: During long-term operation, sealing pairs (e.g., valve seat and disc, valve ball and seat) suffer from media erosion, particle abrasion, or corrosion, leading to uneven sealing surfaces and resulting in minor or significant leakage. Emergency Measures: · Minor Leakage: Adjust compression force (e.g., tighten bonnet bolts) to temporarily reduce leakage. · Severe Leakage: Immediately shut down the system to replace or regrind sealing components; replace the entire valve if necessary. Prevention Recommendations: Conduct regular inspections, select valves with appropriate materials and wear-resistant designs. For media containing solid particles, use hard-sealing structures.   2. Packing Aging or Gland Loosening   Cause: Valve stem sealing uses packing materials (e.g., graphite, PTFE), which may age, dry, or crack over prolonged use. Temperature fluctuations can also cause gland loosening, leading to leakage at the packing box.  Emergency Measures: · Tighten packing gland bolts to increase packing compression. · If ineffective, add or replace packing material. · Avoid over-tightening to prevent increased operating torque or stem damage. Prevention Recommendations: Regularly replace packing; select materials compatible with the media and operating temperature. For critical equipment, consider spring-loaded packing glands.   3. Casting Defects or Corrosion Perforation in Valve Body/Bonnet   Cause: Some low-quality valves have casting defects such as sand holes or shrinkage cavities. Prolonged exposure to corrosive media can cause localized perforation of the valve body, resulting in uncontrollable leakage. Emergency Measures: · For small leaks, temporary repairs using metal adhesives or cold welding are possible. · Large-scale damage requires immediate valve replacement. · For high-pressure or toxic/hazardous media, no pressurized repair is allowed; follow shutdown procedures strictly.  Prevention Recommendations: Purchase valves from reputable manufacturers; use corrosion-resistant materials (e.g., 304/316L stainless steel). Perform regular wall thickness inspections on critical pipelines.   Common Questions & Answers (Q&A)   Q1: Can all valve leaks be fixed by replacing packing?A: No. Packing replacement is effective only when leakage is due to packing aging or gland loosening. If the leakage stems from seal surface or valve body damage, other me...

  • Can Oil Pass Through a Strainer? How Pre-Filtration Works in Lubrication Systems
    Can Oil Pass Through a Strainer? How Pre-Filtration Works in Lubrication Systems
    2025-05-20

    In any efficient and reliable lubrication system, oil cleanliness is a core factor affecting equipment lifespan and operational efficiency. Strainers, as the front-line filtration devices in lubrication systems, play a critical role in pre-filtration. However, engineers and operators often raise the following questions: Can oil pass through strainers smoothly? What exactly is the function of a strainer? How does it differ from subsequent fine filters?   This article systematically explains the role of strainers in lubrication systems, covering their working principles, pre-filtration objectives, and practical applications across different systems.   1. Can Oil Pass Through a Strainer?   Answer: Yes, but with limitations.   (1) Strainer Structure Allows Oil Flow A strainer is fundamentally a low-precision filter made of stainless steel mesh or perforated metal plates. It features uniform pores, typically sized between 80–500 μm (micrometers), allowing most clean oil to flow through unimpeded.   (2) Contaminants Are Blocked Particles such as metal shavings, seal fragments, and carbon deposits in the oil are intercepted by the strainer, preventing them from entering the oil pump or other critical components.   (3) Oil Temperature and Viscosity Affect Flow Efficiency Low temperatures or high-viscosity oil may reduce flow rates or even cause blockages. This is one reason for low oil pressure during system startup.   2. Objectives and Significance of Pre-Filtration   (1) Protecting the Oil Pump Internal pump components (gears, impellers, or plungers) are highly sensitive to solid particles. Pre-filtration prevents particles from entering the pump, avoiding premature wear or seizure.   (2) Reducing Load on Primary Filters By intercepting large contaminants, strainers allow primary filters (e.g., oil filter cartridges) to focus on finer impurities, extending their service life and maintaining stable system flow.   (3) Lowering System Failure Rates Pre-filtration reduces risks such as pump failure, orifice blockages, and lubrication breakdown caused by foreign particles, enhancing overall system reliability.   3. Typical Applications of Pre-Filtration Devices   Application System Strainer Installation Position Strainer Type Internal Combustion Engine Lubrication Oil sump → Pump inlet Coarse metal strainer Hydraulic Systems Tank outlet → Pump suction port Suction strainer or basket strainer Turbine Lubrication Systems Pump inlet Dual-chamber switchable suction strainer Transmission/Clutch Systems Oil sump → Circulation pump inlet Perforated plate + magnetic strainer   4. Design and Usage Considerations for Strainers   (1) Pore Size Selection Must Align with System Precision Requirements 80–100 μm: Typical for engine oil systems. 150–300 μm: Used in hydraulic equipment. >400 μm:  Suitable for low-pressure or open-loop systems.   (2...

  • Are Ball Valves Suitable for Water Systems? A Practical Guide for Engineers & Installers
    Are Ball Valves Suitable for Water Systems? A Practical Guide for Engineers & Installers
    2025-04-30

    Ball valves, with their simple structure, easy operation, and excellent sealing performance, have become widely used control components in both industrial and residential sectors. Particularly in water supply systems, an increasing number of engineers and installers are choosing ball valves as the primary fluid control device. But are ball valves truly suitable for water systems? How should one properly select and install them to ensure long-term stable operation? This article provides a comprehensive overview from the perspectives of structural principles, performance characteristics, and application recommendations. 1. Advantages of Ball Valves in Water Systems (1) Quick Opening and Closing Ball valves can complete the opening and closing operation with a simple 90° rotation, making them easy to operate and highly responsive—ideal for emergency situations or water systems that require frequent switching.   (2) Excellent Sealing Performance High-quality ball valves are equipped with PTFE or reinforced sealing materials, enabling zero leakage. They are particularly suitable for water supply systems in residential buildings, commercial complexes, and industrial facilities where sealing performance is critical.   (3) Compact Structure and Space-Saving Compared to gate valves or globe valves, ball valves occupy less space and offer flexible installation, making them ideal for water modules with high equipment integration.   (4) Strong Corrosion Resistance Ball valves made of stainless steel, brass, or plastic materials (such as UPVC) offer excellent corrosion resistance, capable of handling various water qualities (soft water, hard water, reclaimed water) and different additives.   2. Application Scenarios Analysis Ball valves are suitable for the following types of water systems: (1) Domestic Water Systems: Such as internal building water supply, point-of-use control for sanitary fixtures, and garden irrigation systems. (2) Industrial Water Systems: Such as cooling water circulation systems, boiler feedwater systems, and water supply for cleaning equipment. (3) Water Treatment Systems: Including reverse osmosis pretreatment, greywater recycling, and wastewater transfer processes. (4) Special Applications: High-pressure hot water systems or cleaning water containing chemical additives.   However, caution should be exercised in the following scenarios: (1) High-Frequency Modulation Conditions Standard ball valves are not suitable for precise flow regulation. It is recommended to use V-port ball valves or control-type electric ball valves. (2) Water Containing Sand, Gravel, or High Levels of Suspended Solids A Y-strainer should be installed to prevent particle blockage or damage to the sealing surfaces. (3) High-Temperature Hot Water Systems High-temperature ball valves with metal sealing structures should be selected to prevent seal aging and deformation.   3. Key Selection Criteria To ensure stable operation o...

Company News
What is a Lug Type Check Valve?
What is a Lug Type Check Valve?
2025-02-27

In industrial pipeline systems, check valves are essential components used to prevent backflow of media. Among them, the lug type check valve is favored in many applications due to its unique structure and installation method.     Structural Features The lug type check valve is a one-way valve with threaded lug connections. It typically consists of a valve body, valve disc, valve seat, and a spring (in some models). The most notable feature of this valve is the presence of multiple threaded lug holes on both sides of the valve body, allowing it to be directly bolted to the pipeline flanges without the need for additional nuts. Common materials used include carbon steel, stainless steel, and ductile iron, which are selected based on the specific operational requirements. Compared to the wafer check valve, the lug type check valve offers a more secure installation, capable of withstanding higher pipeline loads. It also supports single-end maintenance, making it suitable for applications that require frequent disassembly and maintenance.   Working Principle: Unidirectional Flow, Preventing Backflow The core function of the lug type check valve is to ensure that the fluid flows in only one direction. In the event of backflow, the valve disc quickly closes to prevent damage to equipment caused by the reverse flow of the medium.   (1) During normal flow: The fluid pressure pushes the valve disc open, allowing the medium to flow smoothly through the pipeline.   (2) When the flow decreases or backflow occurs: The valve disc automatically closes under the action of the spring or gravity, preventing the backflow of the medium and protecting the pipeline and equipment from damage. Some lug type check valves are equipped with a spring-assisted closing mechanism, which responds more quickly to fluid changes, reduces water hammer effects, and enhances system safety.   Main Application Scenarios Due to its unique structure and stable performance, the lug type check valve is widely used across various industries:   (1) Water Treatment and Supply Systems It ensures one-way water flow, preventing backflow when pumps stop, and protects the system from damage.   (2) Oil and Gas Pipelines Suitable for high-pressure and high-temperature conditions, it prevents backflow of fluids from impacting equipment.   (3) Chemical Industry In pipelines conveying corrosive media, lug type check valves made from corrosion-resistant materials ensure production safety.   (4) Power Plants and Boiler Systems Used in steam delivery pipelines to prevent pressure fluctuations from affecting equipment.   (5) Industrial Fluid Control Ideal for systems transporting various liquids, gases, or low-viscosity fluids, improving system stability.   Advantage (1) Stable Installation The threaded lug design allows the valve to be installed or removed independently without affecting the entire pipeline system, making maintenance easier. &nbs...

Successful Application of HP Vapo Drain Isolation Valve in Singapore
Successful Application of HP Vapo Drain Isolation Valve in Singapore
2024-09-06

Recently, DERVOS successfully completed a local project in Singapore, providing high-quality globe valve products that ensured efficient operation and safety throughout the project. Background The client for this project was a Singapore-based on-site repair and maintenance company, primarily responsible for the daily maintenance and emergency repairs of industrial facilities. Their core requirement was to provide reliable isolation valves for high-pressure steam systems, ensuring efficient and safe operation under high-pressure and high-temperature conditions. Facing issues such as valve aging and high maintenance costs, the customer urgently needed a solution that could provide long-term stable performance. Product Features To meet the customer's strict requirements for steam medium management, we provided a high-pressure steam isolation globe valve. This valve is specifically designed for steam isolation, featuring excellent high-pressure resistance. It is manufactured using precision machining processes to ensure stable sealing and long-lasting performance, even under high-temperature and high-pressure conditions. The valve not only meets strict international standards but also underwent multiple tests at the project site, demonstrating exceptional performance. Project Results The globe valve was successfully installed and put into operation. The client reported that their high-pressure steam system is running smoothly, with more stable and safer operation. The precise control of the valve not only improved the efficiency of maintenance work but also significantly reduced system failures and safety risks. The client highly praised the performance and service of our products, stating that our solution greatly supported their daily maintenance and emergency response capabilities. The success of this project has not only enhanced the client's maintenance efficiency and system safety but also laid a solid foundation for future cooperation between both parties. We are proud to have been involved in this project and look forward to continuing to provide high-quality fluid control solutions for our clients in the future.

Golden Years, Timeless Classics - A Wonderful Review of the DERVOS 16th Anniversary
Golden Years, Timeless Classics - A Wonderful Review of the DERVOS 16th Anniversary
2024-07-05

On the evening of June 27, 2024, DERVOS joyously celebrated its 16th anniversary. We not only invited esteemed partners to join us in the celebration, but also meticulously planned a unique journey through time. With the theme "Golden Years, Timeless Classics," we took a nostalgic trip back to the 1990s in Hong Kong. The celebration was filled with a sense of nostalgia and joy, with every detail seemingly transporting us through time to experience the unique charm of that golden era. To match the theme, all partners and colleagues carefully prepared Hong Kong-style outfits, with many colleagues even mimicking classic looks. We specially arranged a fashion show for the occasion. Everyone confidently walked the catwalk, showcasing their Hong Kong-style elegance. Under the flash, everyone exuded a unique charm, as if time had turned back, and the glamour and charm of the 1990s were once again brought to life. In order to let our partners to experience the essence of traditional Chinese culture, we meticulously prepared a "lacquer fan" making activity. By dripping different pigments into the water, the fans spun in the water, creating unique and beautiful patterns that left everyone in awe. Each lacquer fan became a one-of-a-kind piece of art, embodying the creativity and ingenuity of our clients. Our dear partners wrote blessings for Dervos on folding fans and stamped their own exclusive seal, leaving behind cherished memories. The versatile Dervoser added endless joy to the celebration. Sheila and Noisy's jazz dance performance brought the atmosphere to a climax. As the dynamic music played, their passionate performance energized everyone. With the explosive background music, everyone took to the dance floor together, dancing and celebrating this unforgettable moment. That night, we not only reminisced about the glorious past but also looked forward to future prospects. Dervos will continue to uphold the spirit of "Timeless Classics, Everlasting Brilliance," and together with every customer and colleague, write even more magnificent chapters. We thank everyone who has supported and accompanied Dervos, and we look forward to continuing our journey together, creating a better tomorrow.

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