Recently, Dervos Valve helped a client in Hungary overcome a common challenge in industrial steam systems: how to safely isolate high-temperature pipelines without leakage or downtime. Operating with saturated steam at around 250°C and exposed to temperatures as low as -39°C, the client’s system demanded a solution that was both robust and reliable. Traditional valves often failed to maintain a tight seal under such conditions, and conventional isolation methods required depressurizing the line, increasing downtime and operational risk. To address these challenges, Dervos supplied a DN400 PN40 sliding line blind valve, engineered specifically for the project’s harsh conditions. The valve’s sliding blind mechanism allows operators to switch between flow and isolation positions without depressurizing the system, enhancing safety and efficiency during maintenance. Built with forged 20GML steel and a metal-to-metal stainless steel sealing structure, the valve delivers reliable performance under both high-temperature steam and extreme outdoor climates. Its full-bore design minimizes flow resistance, while the worm gear manual actuator ensures smooth and controlled operation even at large sizes and high pressure ratings. Safety features such as anti-misoperation devices and protective blind plate structures further reduce the risk of errors during handling. Since installation, the valve has enabled leak-free operation, safer maintenance procedures, and stable performance in extreme temperatures. Designed for a service life exceeding 30 years, it provides a long-term, low-maintenance solution, giving the client confidence in their steam system’s reliability and safety. This project highlights how a carefully engineered sliding line blind valve can solve critical isolation challenges in high-temperature steam applications, combining operational safety, durability, and efficiency in one solution.
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 When the valve is fully open, the gate is completely withdrawn from the flow path, allowing the fluid to pass through with minimal obstruction.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 ...
3" 600LB globe valve is made according to BS1873 standard. The valve body is made of ASTM A351 CF8+STL. It has the structural characteristics of bolt cover and straight through type. Its connection mode is RTJ. 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:
ASTM A351 CF8+STLMethod of Operation:
Hand WheelProduct Description
|
Type |
Globe Valve |
|
Size |
3" |
|
Pressure |
600LB |
|
Connection |
RTJ |
|
Operation |
Hand Wheel |
|
Body Material |
ASTM A351 CF8+STL |
|
Design Norm |
BS1873 |
|
Face to Face Dimension |
ASME B16.10 |
|
Flange Dimension |
ASME B16.5 |
|
Test & Inspection Code |
API 598 |
|
Temperature |
-29 ~ 425°C |
|
Applicable Medium |
Water, Oil and Gas |
Features
1. The manufacturing process is relatively good and easy to maintain;
2. Small working stroke and short opening and closing time;
3. Good sealing performance, low friction between sealing surfaces, and long service life.
Technical Drawing
Dimension Checking
Pressure Testing
Packing
Inspection report
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The PN16 DN50 stainless steel flanged globe valve has straight pattern structure, bolted bonnet and handwheel operation. The OS&Y globe valve is designed as per DIN 3356. Quick Detail Type Globe Valve Norminal Size DN50 NorminalPressure PN16 Construction BB, Rising Stem, Plug Disc, Integral Seat ConnectionType Flange OperationType Gearbox Design Code DIN 3356 Face to Face DIN 3202 Flange End DIN 2543 Test & Inspection DIN 3230 Body Material Stainless Steel TrimMaterial Stainless Steel Temperature Range -196℃~+800℃ Medium Water, Oil and Gas Origin China Design Feature 1.Straight pattern body structure 2.OS&Y, Rising Stem 3.Bolted Bonnet 4.Available with bevel gear operation 5.Plug type disc 6.Little abrasion on sealing face during valve operation 7.Smaller installation space required Dervos Main Product Range With a complete product range, Dervos product lists cover gate, globe, check, ball, butterfly, check, plug valve and strainers. We can also provide marine valve, pressure reducing valve, control globe valve, wellhead valve and so on
2" 600LB globe valve is made according to API 623 standard. The valve body is made of ASTM A351 CF8M. It has the structural characteristics of low in and high out and welded valve seat. Its connection mode is RF. And it has hand wheel operation mode.
3" 300LB stainless steel globe valve is made according to BS1873 standard. The valve body is made of A351 CF8M. It has the structural characteristics of ammonia shut-off valve. Its connection mode is RF. And it has handwheel operation mode.
1” 300LB Stainless Steel Flange Globe Valve is made according to API602 standard. The valve body is made of A182 F316. It has the structural characteristics of Bolted Bonnet, Parabolic Disc. Its connection mode is RF (125-250AARH). And it has hand wheel operation mode. Product Parameters Type Stainless Steel Globe Valve Size 1” Pressure 150LB Connection RF Operation Hand Wheel Body Material A182 F316 Design Norm API 602 Face to Face ASME B16.10 Flange dimension ASME B16.5 Test & Inspection Code API 598 Temperature -46 ~ 200°C Applicable Medium Water, Oil and Gas Features 1.Constructed from F316 stainless steel, offering excellent corrosion resistance and durability for 300LB pressure applications. 2.Globe valve design with RF flange, compliant with API 602, ensures precise flow control and reliable sealing performance. Technical Drawing Stainless Steel Globe Valve Technical Drawing Dimension Checking Pressure Testing Nameplate & Packing Inspection Report
The 12 inch 150 LB cast steel globe valve is made of carbon steel WCB body and trim 8, with gearbox, RF flange, BB, and plug disc. Quick Detail Type Globe Valve Size 12'' Pressure Class 150 Construction Bolted Bonnet, Straight Pattern,Plug Disc, OS&Y Connection Flanged Connection Operation GearOperated Design Code BS 1873 Face to Face ASME B16.10 Flange Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB TrimMaterial Trim 8 Temperature Range -29℃~+427℃ Application WOG Origin China Dimension Class 150 NPS in 2 2 1/2 3 4 5 6 8 10 12 DN mm 50 65 80 100 125 150 200 250 300 L-L1 (RF-BW) in 8 8-1/2 9-1/2 11-1/2 14 16 19-1/2 24-1/2 27-1/2 mm 203 216 241 292 256 406 495 622 698 L2 (RTJ) in 8-1/2 9 10 12 14-1/2 16-1/2 20 25 28 mm 216 229 254 305 368 419 508 635 711 L3 mm 102 108 121 146 178 203 248 311 349 H (OPEN) in 14-11/16 15-3/8 16-9/16 20-1/4 21-3/16 22-5/15 24-5/8 28 39 mm 373 390 421 515 538 567 626 712 990 W in 7-7/8 9-7/8 9-7/8 11-13/16 11-13/16 13-3/4 15-3/4 17-3/4 24 mm 200 250 250 300 300 350 400 450 610 WT (kg) RF 22 29 42 64 77 105 154 288 507 BW 19 25 34 49 65 82 131 249 430 Related Knowledge What is the difference between a gate valve and a globe valve? Gate valves and globe valves are two of the most common valves we know. The differences beween them are: 1.Gate valve is used only for on-off function. But the globe valve could be used for shutting off and throttling at the same time. 2.The flow resistance of a globe valve is larger than a gate valve. Likewise, globe valves have more pressure drop than gate valves. 3.The gate valve require larger installation space than a globe valve from the perspective of opening height. 4.The gate valve sealing face suffers more abrasion than a globe valve. 5.The torque value of a globe valve is larger than a gate valve. Quality Checking Quality means everything in Dervos. Quality checking team will do inspections according to standard procedure and provide reports. Our QC team will check valve quality from casting and forging, machining, pressure testing, dimension checking, painting & packing.
DN200 PN25 Y Type Strainer is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.0619. It has the structural characteristics of Y-shaped, mesh size: 1.6 mm, without drain plug. Its connection mode is RF.
This butch of gate valves are ranged from 3 inches to 32 inches. With non-rising gate valves and solid wedge, which are not regularly found in such big sized valves, these gate valves are quite special and reliable.
3/8" 800LB Y Type Strainer is made according to ASME B16.34 standard. The valve body is made of HC-276. It has the structural characteristics of Y-Type, Bolted Bonnet. Its connection mode is NPT.
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
1" 800LB gate valve is made according to API 602 standard. The valve body is made of A182-F5. It has the structural characteristics of rigid gate, welded bonnet and extended valve body 100mm. Its connection mode is BW*NPT. And it has hand wheel operation mode.
2" 300LB Globe Valve is made according to BS1873 standard. The valve body is made of A494 CU5MCUC. It has the structural characteristics of OS&Y, Bolted Bonnet (BB), Plug-type Disc, materials compliant with NACE MR0175. Its connection mode is RF. And it has Hand Wheel operation mode. Product Parameters Type Globe Valve Size 2” Pressure 300LB Connection RF Operation Hand wheel Body Material A494 CU5MCUC Design Norm BS1873 Face to Face ASME B16.10 Flange dimension ASME B16.5 Test & Inspection Code API 598 Temperature -35 ~ 300°C Applicable Medium Water, Oil and Gas Features 1.CU5MCuC nickel aluminum bronze construction provides excellent resistance to corrosion, cavitation, and seawater environments. 2.Globe valve design with RF flange and hand wheel operation, compliant with BS 1873, ensures accurate flow regulation and reliable shutoff. Technical Drawing Dimension Checking Pressure Testing Spectrum
The basket type strainer has 150LB design pressure and 1 1/2 inch size. The flanged strainer is made of LCC body and stainless steel screen. Quick Detail Type Strainer Size 1.5'' DesignPressure 150LB Construction Bolted Bonnet, Basket Type ConnectionType Flanged Design Code ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material ASTM A352 LCC ScreenMaterial SS304 TemperatureRange -46℃~+345℃ Application Water, Oil, Gas Company Profile Founded in Xiamen in 2008, DERVOS VALVES INDUSTRY CO., LTD has accumulated rich experience in supplying and exporting industrial valves, from general types of gate valve, globe valve, check valve, ball valve, butterfly valve, plug valve, strainer to special valves like needle valve, control valve, relief valve, safety valve and steam trap. Dervos people are committed to provide our customers with best possible service and valve products at a competitive price. With over 500 valve suppliers, the rich resources we own enable us to find the most suitable products in a very short time for our customers. Purchasing System Dervos purchasing system plays an important role in order follow up and supplier management. What does our purchasing team do? -Confirm production plan with the factory -Follow up the order according to the production plan very closely -Take every measure to initiate all related resources to solve the delay crisis -Seek new suppliers and put them into our supplier pool by evaluating them on quality, equipment, certificates, price level, technical supports etc -Do annual evaluation on current suppliers and eliminate those unqualified ones. All these actions will make sure that clients’ order will be delivered on time and we can find most suitable products among qualified suppliers in an efficient way.
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