In industrial piping systems, gate valves are generally considered low-resistance isolation valves. When the valve is fully open, the gate is completely withdrawn from the flow path, allowing the fluid to pass through with minimal obstruction. However, from a strict engineering perspective, not all gate valves are classified as full port valves. If the seat bore is equal to or very close to the pipeline internal diameter, the flow experiences little or no restriction. In this case, the valve can be considered full port (or near full port). This design is commonly used in oil and gas pipelines, water transmission systems, and other applications where low pressure drop is required. If the seat bore is slightly smaller than the pipe internal diameter, a minor flow restriction will occur inside the valve. In such cases, the valve is more accurately described as reduced bore. This configuration is more common in smaller sizes or cost-optimized valve designs. In engineering practice, a simple selection logic can be applied: ● If the system requires minimum flow resistance or pipeline pigging, the valve bore must match the pipeline diameter. ● If the valve is used for general isolation purposes, most standard gate valves can already meet the required flow capacity. Therefore, a concise conclusion can be drawn: Gate valves are typically close to full port designs, but whether they are truly full bore depends on whether the seat bore equals the pipeline internal diameter. QA Q1: Are gate valves always full bore?Not necessarily. If the seat bore equals the pipe internal diameter, the valve can be considered full bore. If it is slightly smaller, it is classified as reduced bore. Q2: Why do gate valves have relatively low flow resistance?When the valve is fully open, the gate is completely removed from the flow path, allowing the fluid to pass through in a nearly straight line, which results in low pressure drop. Q3: Are gate valves suitable for high-flow pipelines?Yes. If the system requires low pressure drop, gate valves are commonly used. Q4: Is the concept of full port the same for gate valves and ball valves?Not exactly. For ball valves, the bore size is determined by the ball port diameter, while for gate valves, it is mainly determined by the seat bore diameter.
Large diameter ball valves are commonly used in industries such as petroleum and chemical processing, power generation, long-distance pipeline transportation, and large-scale water treatment systems. If installation is not performed correctly, it may lead to sealing leakage, valve jamming, or structural stress damage. Therefore, proper installation practices are essential to ensure long-term stable operation. 1. Pre-installation Inspection If pre-installation inspection is insufficient, operational failures are more likely to occur during service. First, inspect the valve body for transportation damage. If scratches, impact marks, or deformation are found on the valve body or sealing surfaces, installation should be stopped and the supplier should be contacted. Next, verify valve model, pressure rating, and connection standards. If the system design pressure does not match the valve pressure class, operational safety risks may occur. For example, if a low-pressure class valve is mistakenly used in a high-pressure pipeline system, the valve body may experience plastic deformation under water hammer impact. It is also necessary to check the condition of the ball surface and sealing rings. If there are scratches on the ball surface, sealing performance will be reduced. This is especially critical in gas transmission systems where micro-leakage is more likely. 2. Installation Direction Large diameter ball valves usually have a flow direction marking. If the installation direction is incorrect, the following problems may occur: If the fluid flow direction matches the design direction, the operating torque will remain more stable. If the valve is installed in reverse, the stem may experience increased mechanical load, which will accelerate stem wear during long-term operation. For double-seal bidirectional ball valves, although bidirectional flow is allowed, installation according to the marked flow direction is still recommended to ensure more uniform sealing stress distribution. In high-temperature or steam systems, if the installation direction is incorrect, thermal expansion may accelerate sealing ring aging. 3. Pipeline Stress Control Large diameter ball valves are heavy. If installed without proper support, additional bending moments may be transferred to flange connections. If pipeline systems experience axial displacement, pipeline supports should be installed for segmented fixation. If support structures are not provided, the valve body may bear long-term gravitational tensile load, eventually causing flange seal failure. It is generally recommended to install independent supports on both sides of large diameter ball valves. If the pipeline system is subject to thermal expansion and contraction, expansion compensation devices must be installed; otherwise, sealing surfaces may gradually fail. 4. Bolt Tightening Process Flange connections of large diameter ball valves usually ...
This year’s Dervos annual conference was noticeably more grand and well-organized than in previous years. In the morning session, each department delivered its annual work summary, reviewing key projects and achievements over the past year. Teams also openly shared the challenges encountered during implementation and the practical experience gained along the way. Through this cross-department exchange, everyone developed a clearer understanding of one another’s responsibilities and workflows, laying a stronger foundation for future collaboration and communication. In the afternoon session, the Outstanding Employee awards were presented. Each nominee shared their work achievements and practical experience, demonstrating a strong sense of responsibility and execution across different roles. It is precisely this proactive mindset, collaborative spirit, and down-to-earth working approach of Dervos employees that drives the team steadily toward its shared goals. Showing up on time every single day throughout the year — that’s quite an achievement. Ian has now received the Perfect Attendance Award for two consecutive years. During the annual conference, Dervos also presented medals and exclusive commemorative gifts to employees who have completed five years of service. Dervos values the long-term dedication and consistent commitment of its team members, and sincerely appreciates the trust and contributions they have made over the years. For many at Dervos, the company is not only a platform for professional growth, but also a stage where shared goals and collective efforts come to life. In the evening, the annual conference transitioned into the banquet segment. Performances and interactive games were seamlessly interspersed, creating a relaxed yet organized atmosphere. Laughter and cheers echoed throughout the venue, and in the moment the camera shutter clicked, the excitement and joy were captured in a single frame. Eric said: "Let’s dream together, DERVOS's dream. A dream where we all play a part, piece by piece, it becomes a reality." For Dervos, the annual meeting is not just about "summarizing the year," but about bringing our hearts together, strengthening our resolve in doing the same thing, and then continuing to move forward, step by step, with steady progress.
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.
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.
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.
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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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.
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.
1”2500LB Y Type Strainer is made according to ASME B16.34 standard. The valve body is made of A182-F316H. It has the structural characteristics of Y-Type, Pressure Self-Sealing. Its connection mode is BSPT.
API6D swing type check valve RF connnection bolted bonnet full pore WCB body, WCB+13Cr disc, A105+13Cr seat ring, WCB hinge. Suitable temperature in -29℃~+425℃ Quick Detail Type Swing Check Valve Size 4 inch-6 inch Design Pressure CL600 Construction BC, Swing type ConnectionType Flange OperationType - Body Material WCB DiscMaterial WCB+13Cr Hinge Material WCB Seat Material A105+13Cr Design Code API 6D Face to Face Dimension ASME B16.10 Test and Inspect API 598 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China
DN25 PN40 Single Plate Wafer Type Check Valve is made according to API594 standard. The valve body is made of 1.4541. It has the structural characteristics of Single Disc Wafer. Its connection mode is Wafer Type. Product Parameters Type Single Plate Wafer Type Check Valve Size DN25 Pressure PN40 Connection Wafer Type Body Material 1.4541 Design Norm API 594 Face to Face En558-1Ser.49 Flange end En 1092-1 Test & Inspection Code API 598 Temperature -10 ~ 200°C Applicable Medium Water, Oil and Gas Features 1.Single plate wafer design enables compact installation between flanges while preventing backflow. 2.Rated PN40 and fully tested to API 594 standards for reliable sealing and long-term operation. Technical Drawing Dimension Checking Pressure Testing Painting Spectrum Nameplate & Packing Inspection Report
6" 150LB strainer is made according to ASME B16.34 standard. The valve body is made of ASTM A352 LCB. It has the structural characteristics of Y-shaped and bolt cover. Its connection mode is RF.
With butt weld end and gearbox, the fully welded ball valve is designed per ASME B16.34. The one piece ball valve has trunnion type ball, antistatic design and full port structure. Quick Detail Type Ball Valve Size 10" Pressure ANSI 300 Construction Trunnion Type, One Piece Body, Full Bore, Fully Welded Connection Butt Weld (BW) Operation Gearbox Body Material Forged Steel A105 Design API 6D Pressure & Temp ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.25 Inspection API 598 Temperature Range -29℃~+125℃ Media W.O.G Related Knowledge What is a fully welded ball valve? What is the benefit and advantage of a fully welded ball valve? A fully welded ball valve is welded after forging without any bolted connection on the body. Compared with flanged ball valve, it features in maximum strength at minimum weight. The design of the valve gives it advantage: -Overall small size and light weight -Fewer leak paths on the body -High machining precision of ball part -High resistance to external and internal pressure and strength 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.
8" 150LB Y type strainer is made according to ASME B16.34 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of equipped with a drain plug and structural length of 495mm. Its connection mode is RF.
API602 Gate Valve Bolt Bonnet Outside Screw Yoke Solid Wedge Reduced Bore Butt Weld Connection SCH80S A182 F11 Body Trim #5(13%Cr+STL) 900LB 1 inch 3/4 inch Quick Detail Type GateValve Size 3/4 inch-1 inch Design Pressure CL900 Construction BB, OS&Y ConnectionType BW OperationType Handwheel Body Material F11 WedgeMaterial F6a+STL Stem Material F6a Seat Material F6a+STL Design Code API 602 Face to Face Dimension ASME B16.10 Test and Inspect API 598 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China API602 Gate Valve 1 Inch 0.75 Inch 900LB BW Handwheel
3/4'' 800LB gate valve is made according to API 602 standard. The valve body is made of A182-F316. It has the structural characteristics of bolt cover, OS&Y. Its connection mode is SW. And it has hand wheel operation mode.
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.
1" 800LB forged steel gate valve is made according to API602 standard. The valve body is made of A182-F304L. It has the structural characteristics of bolt cover, rigid gate plate. Its connection mode is SW. And it has hand wheel operation mode.
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