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 When the valve is fully open, the gate is completely withdrawn from the flow path, allowing the fluid to pass through with minimal obstruction.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.
DN200 PN16 Bellow Seal Globe valve is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.4408. It has the structural characteristics of body cover bolt, rising pole bracket, angle type, corrugated pipe seal and structural length of 255mm. Its connection mode is RF. And it has hand wheel 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:
EN 10213 1.4408Method of Operation:
Hand Wheel
|
Type |
Bellow Seal Globe Valve |
|
Size |
DN200 |
|
Pressure |
PN16 |
|
Connection |
RF |
|
Operation |
Hand Wheel |
|
Body Material |
EN 10213 1.4408 |
|
Design Norm |
BS EN 13709 |
|
Face to Face Dimensions |
Client's Std. |
|
Flange Ends Dimensions |
BS EN 1092-1 B1 |
|
Test & Inspection Code |
BS EN 12266 |
|
Applicable Medium |
Water, Oil and Gas |
1. Adopting a double seal of corrugated tube and packing to prevent medium leakage and ensure zero leakage;
2. Built in guiding structure to avoid excessive expansion and contraction of the corrugated pipe, extending its service life.
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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.
Dervos bellow seal globe valve is designed as per EN13709 with face to face dimesnsion per EN558. The special designed bellow seal make sure zero leakage from stem. Quick Detail Type Globe Valve Norminal Size DN 65 NorminalPressure PN 40 Construction Bolted Bonnet, Rising Stem, Bellow Sealed ConnectionType RF Flange Operation Handwheel Design Code EN13709 Face to Face EN 558 Connection EN1092 Test & Inspection EN12266 Body Material Carbon Steel 1.0619 Bellow Material SS304, SS316, SS316L and etc ApplicableTemp -29℃~+420℃ Application Water, Oil, Gas Structure Feature 1. Standard design of double-wall bellow seal 2. Heat-dissipating bonnet design; 3. With lubricant storage device; 4, With design of circlip to fix stem nut; 5. Reasonable product structure, reliable sealing performance and good appearance; 6. The sealing surface is welded with Co-based hard alloy, which has good wear resistance, corrosion resistance, anti-friction performance and long service life; 7. Stem has nitriding treatment with good corrosion resistance and anti-friction performance; 8. With position indicator for stem movement;
The bellows seal globe valve adopts the bellows seal design, which completely eliminates the shortcomings of the normal valve stem packing seal aging and easy to leak, not only improves the energy efficiency, increases the safety of the production equipment, reduces the maintenance cost and frequent maintenance. It also provides a clean and safe working environment.Its simple structure and the low price makes it almost no "competitors". Quick Detail Type Globe Valve Norminal Size 1.5 Inch NorminalPressure 150LB Construction Bolted Bonnet, Outside Screw & Yoke, Rising Stem, Bellow Seal ConnectionType RF Flange Operation Handwheel Design Code ASME B16.34, API 602 Face to Face ASME B16.10 Flange End ASME B16.5 Test & Inspection API 598 Body Material ASTM A105 ApplicableTemp -29℃~+425℃ Application Water, Oil, Gas Structure Feature 1. Double seal design (corrugated pipe + packing). If the bellows fails, the stem packing will also be avoided; 2. External leakage, and in line with international sealing standards; 3. No fluid loss, reduce energy loss, and improve plant equipment safety; 4. Long service life, reduce the number of maintenance, reduce operating costs; 5. Rugged bellows seal design, ensuring zero leakage of the valve stem, providing maintenance-free conditions. Technical Drawing Dimension 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.
1" 300LB Forged Steel Bellows Globe Valve is made according to API602 standard. The valve body is made of A350-LF2+316. It has the structural characteristics of Welded Bonnet, Rising Stem (OS&Y), Bellows Type. Its connection mode is RF. And it has Handle Wheel operation mode. Product Parameters Type Forged Steel Bellows Globe Valve Size 1” Pressure 300LB Connection RF Operation Hand wheel Body Material A350-LF2+316 Design Norm API602, ASME/B16. 34 Face to Face ASME/B16.10 Flange dimension conform ASME B16.5 Test & Inspection Code API598 Temperature -46 ~ 345°C Applicable Medium Water, Oil and Gas Features 1. LF2 forged steel body offers excellent low-temperature toughness and structural reliability for 300LB service. 2.Bellows-sealed globe valve design compliant with API 602 eliminates stem leakage and ensures safe, precise flow control. Technical Drawing Dimension Checking Pressure Testing Nameplate & Packing
Quick Detail Type Globe Valve Size DN15 DesignPressure PN160 Construction Tee Pattern Connection Socket Welded Design & Manufacture BS5352 Socket Weld ANSI B16.11 Test & Inspection EN12266 Body Material A182 F5+STL Trim Material A276 410; STL Media WOG Description --Tee Pattern is the most common type of globe valve with a z shaped diaphragm. --The seat is oriented horizontally allowing the stem and disk to travel perpendicular to the horizontal line. This alsocontribute to low flow coefficient and higher pressure drop. Features --Good shutoff capability --Moderate to good throttling capability --Shorter stroke (compared to a gate valve) --Available in tee,WYE, and angle patterns, each offering unique capabilities --Easy to machine or resurface the seats --With disc not attached to the stem, valve can be used as a stop-check valve Technical Drawing Dimension Check Witnessing Tests Nameplate & Packing FAQ 1.Can the ordersalways be delivered on time? Our purchasingteam follows up very closely with each order tomake sure on-time delivery for most of orders. In 2018,more than 90% orders were delivered on time, and we are dedicated to doing better. 2.What’s the normal delivery lead time? For normal material, usually the delivery time is about 35~40 days, and for forged material, the delivery canevenbe shortened to 20~25 days. We believe the short lead time can make our offer more competitive and help you secure more orders. Do you have different price levels for us? With our numerous suppliers, different price levels are available with us, so we are able to help you win more customer from different markets requesting for high, medium and low prices. About Dervos Xiamen Dervos Valves Industry Co.,Ltd (stock code 861601), founded in June 2008, is a one-stop industrial valves supplier integrated of R&D, manufacture, resource integration, and trade service. For 12 years, Dervos has been committed to finding solutions for industrial needs and providing professional service for both general and specialized valves.
DN125*DN80 PN25 ball valve is made according to ISO 17292 standard. The valve body is made of ASTM A105. It has the structural characteristics of fixed ball and insulation jacket. Its connection mode is EN1092-1 B. And it has gear operation mode.
3/4" 150LB Y type strainer is made according to ASME B16.34 standard. The valve body is made of A350-LF2. It has the structural characteristics of Y-shaped, bolt cover, filter (100 microns). Its connection mode is RF.
3" 1500LB flat gate valve is made according to API6D standard. The valve body is made of ASTM A995 4A. It has the structural characteristics of BB, OS&Y, with diversion holes. Its connection mode is RTJ. And it has hand wheel operation mode.
The 1 inch 800LB female threaded globe valve has plug disc, reduced port and manual handwheel operation. The valve is made of A105N body and trim 5 as per API 602. Quick Detail Type Globe Valve Size 1'' Pressure Class 800 Construction Bolted Bonnet, Reduced Port, Outside Scew & Yoke ConnectionType NPT Female Thread OperationType Handwheel Operated Design Code API 602 End to End Dimension ASME B16.10 Connection ASME B1.20.1 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material Forged Steel A105 TrimMaterial 13CR+Stellite Temperature Range -29℃~+427℃ Application Water, Oil, Gas Origin China Product Range 1.Size up to 4 inch 2.Design pressure between 150LB to 2500LB 3.Connection: flange, socket weld, thread 4.Operation: handwheel, gearbox, bare stem, with actuators 5.Body material: carbon steel, stainless steel, alloy steel 6.Trim material: trim 1, 5, 8, 10, 12, 16 and ect. 7.Bolted bonnet, pressure sealed bonnet, welded bonnet, screwed bonnet 8.Reduced bore, full bore Inspection Reports Along with each order, Dervos will provide inspection reports and material test reports free of charge after shipment. All these certificates will let you have a clear picture of inspection process and results. Plus, these reports can be used for traceability.
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.
The 6 inch 600LB globe valve, made of ASTM216 WCB, is designed as per API623. It is operated by a handwheel and is connected with pipeline by RF. The disc of the globe valve contain 13Cr, therefore this valve enjoys a better ability to resist corrosion.
3" 600LB ball valve is made according to API6D standard. The valve body is made of A182 F304. It has the structural characteristics of fixed ball, full bore, anti-fire and anti-static and anti-flying valve stem. Its connection mode is RF. And it has IP68 waterproof turbine box operation mode.
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