English

English

Get a Quote
Products

Hot Products

Company News

Advantages of V-port Valves
Advantages of V-port Valves
2020-09-18

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
2020-09-11

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?
2020-09-01

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.

WCB Changeover Valve PN40 Handwheel
加载中...

WCB Changeover Valve PN40 Handwheel

The changeover valve is combined by two valves that are different from nominal diameter--one is DN100, the other is DN150. A handwheel is put on the right side of the valve to help control the large WCB-made device. Designed as per DIN 3356, the valve is usually put in the oil industry.

  • Payment:

    30% when order confirmed, 70% before shipment
  • Product Origin:

    China
  • Color:

    Customization
  • Shipping Port:

    Shanghai, China
  • Lead Time:

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

    ASTM A216 WCB
  • Method of Operation:

    Handwheel
Inquiry now
Product Detail

General Discrption

Changeover , also called selector valve, is a three way device usually for changing the direction of the flow in pipelines. It also can be put in the situation of two safety valves and a pressurized system as a pressure relief system where the changeover valve ensures that we always have one standby valve ready for emergency. The condition also permits regular maintenance can be carried out without interrupting the work of the whole device.


The simple design from Dervos allows easy assembly, dis-assemble and easy maintenance. The valve also can handle various applications--high temperatures, cryogenic service, dangerous fluids and many others.


Design Features

Full Bore: The full-bore channel brings superior transporting performance. This valve is also designed to minimize the pressure drop and flow-resistance.


Zero Leakage: With emission-free packing and the static sealing part of the body, which is double-sealed by oval-ring and metal jacketed graphite gasket, the valve meets the demands of corresponding working conditions.


Long service life: The valve enjoys easy maintenance and long service life, which benefits from the plane sealed sealing face of the valve and the alloy welding technology.


Quick Detail

Type

Changeover Valve

Nominal Diameter

DN100*150

NominalPressure

PN40

Construction

Bolted Bonnet

Connection

RF

Operation

Handwheel

Design & Manufacture

DIN 3356

End to End 

TO MFT’S STD

Flange End Dimension

EN 1092-1 B1

Test & Inspection 

EN 12266-1

Temperature Range

-29℃~+425℃

Body Material

ASTM A216 WCB

Big Disc

ASTM A105+13Cr

Media

W.O.G.etc


 

Technical Drawing

 

Dervos Quality Checking System

In Dervos, we control quality throughout the whole manufacturing process.

 

Casting inspection:

We can find out the problem of raw material, such as shoddy casting, unqualified wall thickness, chemical composition and so on, which ensure that you will not be cheated.  


Machining Inspection:

On the one hand, we could ensure machining accuracy through this process. On the other hand, we could find out machining mistake as early as possible, to win more time for repairing and remaking

 

Final Inspection:

Final inspection activities include document and QC record review, visual examination, dimension check, pressure test, painting and packing check. You don’t need to come and inspect in person and all the documents could be provided as proof. 

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.

Related Products
1/2 Inch NPT Needle Valve
Stainless Steel Needle Valve 1/2 Inch 6000 PSI NPT

The 6000 psi high pressure needle valve is made of stainless steel F316 according to ASME B16.34. The 1/2 inch NPT needle is used for regulating the flow of fluid and suitable for application with high pressure and small flow. Quick Detail Type Needle Valve Size 0.5 Inch DesignPressure 6000 PSI ConnectionType Female Thread FNPT Design Code ASME B16.34 End Connection ASME B1.20.1 Face to Face ASME B16.10 Test & Inspection API 598 Body Material SS316 TrimMaterial SS316 Application Water, Oil, Gas Dervos Certification Certificates are one of the factors our clients are caring about. On clients’ request, we could provide API 5L, API 6A, API 6D, API 607, API 5CT, ISO 9001, PED CE and so on. Why choose Dervos as your partner? One Stop Service Here in Dervos, we can provide you with one stop service by our complete product list, it means, you don’t need to search for various suppliers for different types of valves, and it will surely save your time and energy. All you need to do is choose Dervos and we will provide complete solutions to you.  On Time Delivery Dervos keeps a high percentage of on time delivery. Why could we achieve that? Our purchasing team follows the order very closely. Plus, our QC and sales person will also do monitoring job on each order. Strict Quality Control All the members in the QC team are very experienced and professional. For each order, they will check the raw material, manufacturing process, do the pressure testing on shell and seal, and check the valve dimension per assembly drawing. Lastly, they will inspect the painting and packaging.

WCB Globe Control Valve
Electric Globe Control Valve WCB PN40 DN200 RF

The electric control valve is made of carbon steel WCB designed for precise flow control and regulating. Dervos have many suppliers of different control valve types. Quick Detail Type Globe Control Valve Size DN 200 DesignPressure PN 40 ConnectionType RF Flange Design Code ASME B16.34 End Connection ASME B16.5 Face to Face ASME B16.10 Test & Inspection API 598 Body Material A216 WCB TrimMaterial Stainless Steel Application Water, Oil, Gas Company Profile 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. How we handle complaints When complaints come, how do we handle them? We will reply within 24 hours and ask more proof from clients. Then we discuss with QC and factories to identify the reason. In the third day, we will provide a solution to clients.  

1 Inch 800LB gate valve BB OSY SW
Gate Valve BB OSY SW 1 Inch 800LB

The 1 inch 800LB gate valve is designed as per API 602 with SW and handwheel operation. The stainless steel F316 gate valve has the construction of bolted bonnet, outside screw and yoke.

Bellow Seal Globe Valve With Handwheel
Bellow Seal Globe Valve 1.5 Inch SW A105N OS&Y

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.

Through Conduit Gate Valve
Through Conduit Expanding Gate Valve 18 Inch 600LB API6D

The API 6D through conduit gate valve is designed with double expanding wedges, metal to metal seat and diversion hole for pigging. The valve has good performance on sealing, less flow resistance and is suitable for application with some solids or particles. Quick Detail   Type Gate Valve Size 18'' Design Pressure ANSI 600 Construction Double Expanding Wedges, Fully Metal Seat, With Diversion Hole ConnectionType RTJ Flange OperationType Gearbox Operated Body Material WCB WedgeMaterial A105+STL+ENP StemMaterial 17-4PH SeatMaterial A105+STL+ENP Design Code API 6D Face to Face Dimension ASME B16.10 End Connection ASME B16.5 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China

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.

Carbon Steel Slab Gate Valve
Through Conduit Slab Gate Valve DN200 PN64 Flanged

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  

150LB V ball valve Duplex Stainless Steel 4A
150LB V ball valve Duplex Stainless Steel 4A

The 150LB ball valve, made of Duplex stainless steel 4A, has a special V port ball. The valve is particularly suitable for media containing fibers, tiny solid particles, slurry and so on. 

WCB Gate Valve PN25 DN250 Bolted Bonnet RF
WCB Gate Valve PN25 DN250 Bolted Bonnet RF

The DN250 PN25 gate valve is designed as per DIN 3352. With common parts of a valve, like bolted bonnet, outside yoke and handwheel, its body is made of WCB and STL. Valve body, bonnet,seat and other parts are promised to be traceable.

Stainless Steel CF8 Check Valve
Stainless Steel Non Slam Swing Check Valve 8 Inch 150L

The stainless steel CF8 non return valve features in non slam type disc, ANSI 150 flange end, and full port design.  Quick Detail Type Non Return Valve ( Check Valve) Size 8'' DesignPressure Class 150 Construction Non Slam Type Connection RF Flange Design & Manufacture ASME B16.34 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A351 CF8 Trim Material SS304 Media W.O.G. Available Modifications for Dervos Valves -Valve Pressure -Valve Size -Reduced Bore & Full Bore -Body & Trim Material (Disc, Seat, Pin, Spring) -End Connection (Flange, BW, SW, Thread, Wafer, Lug) -Available Operation (Bare Stem, With Actuators) -Available Counterweight -Available Cylinder -Customizing Coating -Customizing Packaging Related Knowledge What is non-slam check valve? Water hammer is a hydraulic phenomenon that undergoes an abrupt change in its rate of flow and are caused by sudden shutting or slamming. Water hammer will reduce process efficiency, cause valve damage, gasket joint leaks and other problems. The non-slam check valve is designed to reduce water hammer. An internal spring can prevent the disc from slamming close.The design of a non-slam check valve could eliminate pressure flutuations, vibration and damges. Plus, the disc and spring experience minimal wear over time, which will largely extend the service lives of non-slam check compared to swing check valve.

Double Disc Check Valve
Double Disc Check Valve DN3202 PN25 DN100 CF8

The double- disc check valve, made of CF8 stainless steel, has excellent resistance to corrosion. Designed in accordance with DIN 3202, the check valve is about to connect to pipes with WAFER. Quick Detail Type Check Valve Nominal Diameter DN100 NominalPressure PN25 Construction Double disc/ Dual Plate Connection Wafer Type Design & Manufacture DIN 3202 End to End  DIN 3202 Flange End Dimension DIN 2401 Test & Inspection  API 598 Temperature Range -29℃~+425℃ Body Material A351 CF8 Wedge Material A351 CF8 Media W.O.G. Dervos Packaging Good packing means good first impression. Just imagine how do you feel differently when seeing two boxes below? And you will know the reason why in Dervos we value packaging so much. In Dervos, we make sure- 1. Every valve isclean and dry. What do we do? -Clean the valve before packing -Add anti-rust oil -Add flange cover 2. No damageto valves in delivery. How do we achieve this? -Fix the valve with iron wire -Separate the valve with soft material -Layer the valve with plywood 3. Strong box and clear shipping mark

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.

Home

Products

about

contact