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Advantages of V-port Valves
Advantages of V-port Valves

The V-ball valves or V-port ball valves are similar to traditional ball in which there is a V-notch on a ball-shaped disc to control flow by a rotating quarter-turn motion. The “V-port" is a particular design that bring about precise flow and the ability to regulate and control flow by V balls of  different degrees. These special valves are used in a wide range of chemical applications, including the most challenging services with many advantages.   Flow Modulating The accuracy of V-ball valves provides equal percentage flow characteristics. As the ball rotates, desired flow rates can be achieved by positioning the ball anywhere between 0° and 90°.   Bubble tight shutoff V-ball valves have the ability to close tightly. Therefore, no other shutoff valves is required when using a V-ball valve on a globe valve.   Lower pressure drop V-ball valves also have a higher coefficient of flow (Cv) than the same size globe valve, which directs the flow and uses a plug to control the flow through the valve. This means that the flow rate achieved by one shut-off valve can be achieved with a smaller V-ball size.   Higher shutoff pressure. A 90°rotation of the ball allows the V-ball to close at a higher operating pressure. This therefore allows the use of lower torque actuators, resulting in cost savings and increased efficiency for the end user.

Know and Know More About Changeover Valve
Know and Know More About Changeover Valve

There are quite a few types of changeover valves, and according to different standards, there are different subdivisions. But in general, it is mainly four kinds, for motorized changeover valve, manual changeover valve, solenoid valve and electro-hydraulic changeover valve.   1. What is a changeover valve?   Changeover valve, from a professional point of view, is a kind of direction-change valve. It is mainly used to achieve the flow of hydraulic oil, cut off the machine changeover operations, pressure relieving, as well as sequential action control, so its use is very wide.   2. The working principle of reversing valve   The changeover valve uses a  driving mechanism outside the valve to rotate the drive shaft, and then activates the valve plate, etc. So that the fluid can flow into the outlet of the lower part of the valve, and can be changed from time to time to achieve the purpose of periodically changing the flow direction.   3. Changeover valve classification  (1) Motorized changeover valve, it is also known as a stroke valve.    (2) Electromagnetic changeover valve, electromagnetic changeover valve is the use of electromagnetic attraction to manipulate the spool changeover control valve.    (3) Electro-hydraulic changeover valve, electro-hydraulic changeover valve is a composite valve composed of solenoid valve and hydraulic changeover valve.    (4) Manual changeover valve, manual changeover valve is a changeover control valve with a manual lever to manipulate the spool shift direction-changing valve.  

How to extend the service life of lined valves?
How to extend the service life of lined valves?

Among the anti-corrosion materials, PTFE has incomparable excellent performance. In addition to outstanding chemical stability, it also has satisfactory anti-fouling and anti-stickiness, small dynamic and static friction coefficient, good anti-wear performance. Using it as a valve opening and closing the sealing material, the friction between the sealing surface and required operating torque will be reduced, hence product life increases. the application scope can also be extended to the food, pharmaceutical industry and so on. Fluorine lined valves, also known as anti-corrosion valves, are usually found in harsh working conditions. The media is either toxic and harmful chemicals, or pretty corrosive acids and bases or organic solvents. That means improper use and operation will elicit significant economic losses and serious consequences. Applicable media: various concentrations of acid and alkali salt and certain organic solvents. Fluorine is extolled as the world's most ideal anti-corrosion materials, has been widely used in the rotational molding of large equipment and piping lining. Correct use and maintenance of the valve can extend the service life of fluorine lined valves, then what can be done to effectively protect it? 1. Carefully read the instruction manual before use. 2. Use it within the range of pressure, temperature and media given by the nameplate or instruction. 3. To prevent fluorine lined valves from excessive piping stresses due to temperature changes, temperature changes should be minimized and U-shaped expansion joints should be added before and after the valve. 4. For some unstable and easily decomposed media (such media will expand after decomposition,  resulting in an abnormal pressure rise) and media that can cause valve damage or leakage, measures should be taken to eliminate or limit the factors that cause the decomposition of unstable media. 5. For fluorine lined valves in pipelines of toxic, flammable, explosive, highly corrosive media, it is strictly prohibited to replace the packing under pressure. Even the valves are designed with sealing part, it is not recommended to replace the packing under pressure either. 6. For pipelines with self-combustible media, measures should be taken to ensure that the ambient and working temperatures do not exceed the self-combustibility point of the media to avoid the danger from sunlight or external fires.

Pressure Balance Plug Valve With Lever

Inverted Pressure Balanced Lubricated WCB 2 Inch Plug Valve

  • Payment:

    30% T/T When Order, 70% T/T Before Shipment
  • Product Origin:

  • Lead Time:

    30~60 days Ex Works after order confirmation
  • Material:

  • Method of Operation:

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Product Detail

Inverted Pressure Balanced Lubricated Plug Valve is 2 inch and WCB body with metal seated. Apply to temperature lower than 80℃.

Quick Detail 


Plug Valve






Lubricated Type Plug Valve

Connection Type

Flange Connection



Design Code


Face to Face

ASME B16.10

End Connection

ASME B16.5

Pressure & Temp

ASME B16.34

Test & Inspection 


Body Material

A216 WCB

Temperature Range




2 inch inverted pressure balance lubricated plug valve

Natural Gas Plug Valve

2 inch Plug Valve

WCB plug valve metal seal

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The 8 inch lubricated plug valve features in inverted and pressure balanced type structure. The flanged metal seated plug valve is suited for natural gas application. Quick Detail Type Plug Valve Size 8'' Design Pressure 300LB Construction Lubricated Type, Inverted Type, Pressure Balanced Type, Metal Seated Connection Type Flanged Connection Operation Gear Operated Design Code API 599 Face to Face ASME B16.10 End Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material WCC Temperature Range -29℃~+425℃ Application Water, Oil, Gas Dimension Class Size 1 1/2 2 2 1/2 3 4 6 8 10 12 300 B 191 216 241 283 305 403 419 457 502 C 156 165 191 210 254 318 381 445 521 D 20.6 22.2 25.4 28.3 31.8 36.5 41.3 47.6 50.8 E 169 178   219 235 362       F 106 118   143 165 187 248 300 392 O 73 92.1 105 127 157 216 270 324 381 Weight(RF) 16 21   38 60 101 192 281 508 Related Knowledge What is a plug valve? Plug valve is a quater-turn valve whose plug rotates around the centerline of valve body to realize on-off function. The plug valve is used for cutting off, distributing and changing the flow directoin. Currently, plug valves are mainly applicable for small size, normal temperature, and low pressure conditions. The advantages of plug valve are shown below: -Quick opening and closing the valve -Small fluid resistance -Reliable leak-tight service -Available inline maintenance 

API6D inverted pressure balanced lubricated plug valve 150LB
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Trunnion Mounted Ball Valve
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Trunnion mounted ball valve DN300 PN63 full bore Double Block and Bleed PMSS seal(metal seal+soft seal)blowout proof stem gearbox operation with LF2 body, LF2+ENP ball/seat and 410 stem. Quick Detail Type Ball Valve Size DN300 Design Pressure PN63 Construction DBB,Trunnion mounted ball valve ConnectionType Flange OperationType Gearbox Operated Body Material LF2 Ball Material LF2+ENP Stem Material 410 Seat Material LF2 +ENP Design Code API 6D Face to Face Dimension API 6D End Connection ASME B16.5 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China

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The Class 1500 4'' cryogenic ball valve is designed with extended stem for low temperature application. The valve is made of LF2 with fully welded body, butt weld end and gearbox operation.  Design Feature -Fully welded & forged body -Extended stem or bonnet -Full port design and piggable -Anti blow-out stem -Antistatic function - Automatic cavity relief -Bi-directional seat and DBB design -With stem and seat grease fittings Quick Detail Type Ball Valve Size 4" Pressure ANSI 1500 Construction One-Piece Body, Fully Weld, Extended Stem or Bonnet, Full Port Connection Butt Weld Operation Gearbox Operated Body Material Low Temperature Steel A350 LF2 Design Code API 6D Pressure & Temp ASME B16.34 End to End Dimension ASME B16.10 End Connection ASME B16.25 Inspection API 598 Temperature Range -46℃~+200℃ Media Oil, Water, Gas Related Knowledge What is the difference between full bore and reduced bore ball valve? The internal diameter of a full bore ball valve is the same as the inner diameter of the pipe. The full bore ball valve has little resistance and pressure drop to the flow. Plus, the full bore ball valve is piggable. However, the internal diameter of a reduced port (standard port) ball valve is smaller than the inner pipe size. Flow restriction caused by the reduced port will cause a pressure drop. And sometimes a pig to clean the pipe will get stuck in the reduced port ball valve. Certificates Dervos could provide reports upon clients’ requests, such as ISO 9001, PED CE, EAC, API 607, API 6D, API 6A and etc.

Carbon Steel Slab Gate Valve
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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  

Welded Ball Valve Forged Steel Metal Seated
10 Inch Fully Welded Ball Valve Metal Seated Bare Stem

The 20 inch metal seated ball valve is designed for high temperature application or application with solid particulate. The valve has welded body, RF flange connection, bare stem for actuators, belonging to trunnion mounted type. Quick Detail Type Ball Valve Size 20" Pressure ANSI 600 Construction Trunnion Type, One-Piece Body, Fully Welded, Metal to Metal Seat Connection Flanged Operation Bare Stem Body Material Forged Steel ASTM A105 Design Standard API 6D Pressure & Temp ASME B16.34 Face to Face Dimension ASME B16.10 End Connection ASME B16.5 Inspection API 598 Temperature Range -29℃~+200℃ Media Oil, Water, Gas Dimension CLASS 600 DN mm 50 65 80 100 150 200 250 300 350 400 450 500 NPS in 2 2.5 3 4 6 8 10 12 14 16 18 20 L (RF) mm 292 330 356 432 559 660 787 838 889 991 1092 1194 in 11.5 13 14 17 22 26 31 33 35 39 43 47 L1 (BW) mm 292 330 358 432 22 660 787 838 889 991 1092 1194 in 11.5 13 14 17 559 26 31 33 35 39 43 47 L2 (RTJ) mm 295 333 359 435 562 664 791 841 892 994 1095 1200 in 11.63 13.13 14.13 17.13 22.13 26.13 31.13 33.13 35 39.5 43.1 47.3 H mm 153 165 195 213 272 342 495 580 630 725 800 850 in 6.02 6.5 7.68 8.39 10.7 13.5 19.5 22.85 24.8 28.5 31.5 33.5 Do(W) mm 600 850 1250 1300 1500 *350 *350 *600 *600 *800 *800 *800 in 23.62 33.46 49.25 51.22 59 13.8 13.8 23.6 23.6 31.5 31.5 31.5 RF(Kg)   38 56 66 122 217 350 660 820 830 1160 1420 1650 BW(Kg)   31 51 58 117 200 327 605 790 800 1030 1305 1505 *Worm Gear or Electric actuator operated Related Knowledge When to use metal seated ball valve? The seat of a metal seated ball valve is often stellite, stainless steel, or tungsten carbide instead of soft seat material like ptfe, peek, nylon, teflon, and devlon. These metal to metal seat ball valves are especially applicable for: -Media with high temperature -Media with solid particulate for high abrasion -Media with severe condition, like high erosion and corrosion -Media with high viscosity like heavy oil Our Main Product Range Dervos main products include ball valves, butterfly valves, check valves, gate valves, globe valves, and plug valves in different materials, sizes, standards and types as per clients’ requests.

BS 1868 Swing Type Check Valve
8 Inch Swing Check Valve 1500 LB WCB Flanged BB BS 1868

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

150LB high performance double offset butterfly valve WAFER
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The 3 inch 150LB butterfly valve has a double-offset disc design that allows the disc to move off the seat reducing running torque and seat wear. The Wafer type valve can be driven by a gearbox and handwheel or by electric, pneumatic or hydraulic actuator.

3 piece ball valve gear operator A105 4 inch 150LB
3 piece ball valve gear operator A105 4 inch 150LB

The 4 inch 150LB ball valve is a 3-piece one with reduced port, A105 body, F6A stem, ball and seat. The The valve is made as per API6D and is tested under API 598.

Bellow Seal Globe Valve With Handwheel
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Dual Disc Lug Check Valve 150 LB
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 Triple Eccentric Butterfly Valve
Carbon Steel Triple Eccentric Butterfly Valve 150LB 20 Inch

The triple eccentric butterfly valve, made of carbon steel, is designed under Class 150 for a better performance of 0 leakage. With a gear operator, it can be better drove.   Quick Detail Type Butterfly Valve Nominal Size 20 Inch Nominal Pressure Class 150 Structure Triple Offset,Triple Eccentric, Metal Seated Connection Type Wafer Type Operation Gear Operated Design Code API 609 Face to Face ASME B16.10 End Connection ASME 16.5 Test & Inspection API 598 Body Material Carbon Steel Application Water, Oil, Gas   Founded in 2008, DERVOS VALVES INDUSTRY CO., LTD is a professional vendor, exporter and supplier of industrial valves, pipes and fittings. Dervos has expanded its business to five continents around the world, including Europe, Oceania, Africa, America and Asia.   Our commitment is to find the most suitable products for our clients in an efficient way. We adopt modern management skills to make sure efficiency in production and selling system.          

Leave a message

    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.