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 When the valve is fully open, the gate is completely withdrawn from the flow path, allowing the fluid to pass through with minimal obstruction.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 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 .
DN50 PN16 Forged Floating Ball Valve is made according to ISO17292 standard. The valve body is made of ASTM A105. It has the structural characteristics of Full Bore Floating Ball, Fire-safe and Anti-static, Blow-out Proof Stem. Its connection mode is RF.
1/2" 150LB globe valve is made according to API 602 standard. The valve body is made of ASTM A105N+STL. It has the structural characteristics of pass-through type. Its connection mode is RF. And it has hand wheel operation mode.
2" CL150 V-ball valve is made according to API 608 standard. The valve body is made of ASTM A995 4A. It has the structural characteristics of V type. It has RF connection mode, and its operation mode is polished rod torque.
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.
4" 150LB wafer check valve is made according to API 594 standard. The valve body is made of A351 CF8M+STL. It has the structural characteristics of double disc. Its connection mode is wafer.
The 8 inch non return check valve conforms to BS 1868 design code, with bolted bonnet and swing type disc. The flanged check valve is made of carbon steel A216 WCB. Design Feature 1.BB: bolted bonnet 2.Swing type disc 3.Reduced bore design 4.Superior flow rates 5.Minimized friction loss 6.Standard trim material for selection 7.External or internal hinge pin available on request 8.Cylinder and counter weight available on request 9.Bare stem and actuators are available on request Quick Detail Type Check Valve Size 8'' Design Pressure ANSI 1500 Construction Bolted Bonnet, Swing Type Connection Raised Face Flange Design & Manufacture BS 1868 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material Carbon Steel Applicable Temp -29℃~+400℃ Media W.O.G. Dimension Class 1500 NPS in 2 2 1/2 3 4 6 8 10 12 DN mm 50 65 80 100 150 200 250 300 L-L1 (RF-BW) in 14-1/2 16-1/2 18-1/2 21-1/2 27-3/4 32-3/4 39 44-1/2 mm 368 419 470 546 705 832 991 1130 L2 (RTJ) in 14-5/8 16-5/8 18-5/8 21-5/8 28 33-1/8 39-3/8 45-1/8 mm 371 422 473 549 700 841 1000 1146 H (OPEN) in 12-1/4 12-1/4 13 14 15-3/4 20-7/8 22-1/16 25-5/8 mm 310 310 330 355 400 530 560 650 WT (kg) RF 69 93 140 232 490 990 1490 1970 BW 49 74 111 185 375 803 1250 1625
The through conduit slab gate valve, designed as per DIN standard, has the diversion hole for pipeline cleaning. The PN64 parallel disc gate valve is made of carbon steel with RF flange and handwheel. Quick Detail Type Parallel Slab Gate Valve Nominal Diameter DN 200 Nominal Pressure PN 64 Construction Parallel Slabe Gate Valve, With Diversion Hole, Bolted Bonnet, Resilient Seat Connection Flange Operation Handwheel Operation Body Material Carbon Steel Medium Water, Oil and Gas Origin China Design Feature 1.Parellel disc 2.Soft seat and metal seat for choices 3.Full bore design for pigging and less pressure drop 4.Firesafe design 5.Self relieving function 6.Grease fitting for seat and stem 7.Double block and bleed capability 8.With vent and drain port 9.Tight sealing performance Material Part Name Material Body & Bonnet A216 WCB, CF8, CF8M, CF3, CF3M Wedge Alloy Steel (face harden treated), Stainless Steel (with Co overlay) Stem Alloy Steel (face erosion-resistant treated) Seat Alloy Steel (face harden treated, beset F plastic), Steel (with Co overlay, best F plastic) Packing PTFE O-Ring NBR, FEP Sealing Grease
The stainless steel CF8M gate valve is designed with flange connection and handwheel operation per DIN 3352. The PN16 DN200 full port gate valve has OS&Y structure, resilient wedge and replaceable seat. Design Specifications Design and Manufacture: DIN 3352 End to End Dimension: DIN3202 Flange End: EN1092-1 Test & Inspection: EN12266-1/2 Design Feature -Full Bore Design -Superior flow rates & small friction loss -Low torque value for closing and opening the valve -Flexible wedge for better seating and ease of operation -Smooth finish and superior sealing for seat face -Every valve is manufactured with specific number on body for traceability Quick Detail Type Gate Valve Size DN 200 Pressure PN 16 Construction Bolted Bonnet, Rising Stem, Outside Screw and Yoke Connection Flange Connection Operation Handwheel Body Material Stainless Steel CF8M TrimMaterial Stainless Steel Temperature Range -268℃~+648℃ Medium Water, Oil and Gas Origin China Dervos Packaging Packaging is an important part we could never neglect. Dervos has a packaging process for each order to ensure a safe and clear delivery of the order.
8" 2500LB DBB Trunnion Mounted Ball valve is made according to API 6D standard. The valve body is made of A182 F51. It has the structural characteristics of DBB Fixed Ball Valve, Full Bore, Fireproof/Electrostatic/Anti-Exposed Stem Design, Compliant with NACE MR0175. Its connection mode is RTJ. And it has Turbine operation mode with locking device.
DN20 PN40 steam trap valve is made according to GB/T22654-2008 standard. The valve body is made of WCB. It has the structural characteristics of inverted bucket steam trap and model L881F. Its connection mode is RF.
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