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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.

Dual Disc Lug Check Valve 150 LB

Duplex SS Check Valve Lug Type Dual Plate 8 Inch Class 150

  • Payment:

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

  • Color:

  • Shipping Port:

    Shanghai China
  • Lead Time:

    30~55 days Ex Works After Order Confirmation
  • Material:

    Stainless Steel Check Valve
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Product Detail

The 8 inch 150 LB dual disc non return check valve, designed per API 594, has dual plate and lug connection. The retainerless dual  plate check valve is made of duplex stainless steel 4A as its body and trim material.

Quick Detail


Check Valve




Class 150


Dual Plate Type, Retainerless


Lug Type

Design & Manufacture

API 594

End to End

ASME B16.10


ASME B16.5

Pressure & Temp

ASME B16.34

Test & Inspection

API 598

Body Material

Duplex Stainless Steel 4A

Trim Material

Duplex Stainless Steel



Design Feature
1.Shor face to face dimension
2.Small in size with light weight
3.Swift close of disc with small water hammer
4.Vertically or horizontally installed
5.Smooth flow passway with small flow resistance
6.Long cycle life and high reliability

Stainless Steel Check Valves Manufacturers

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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

Retainerless Wafer Lug type Check Valve 6'' 900LB
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The 6 inch Wafer check valve is made in strict accordance to API 594. The body material LCC make sure the lug type valve is capable to handle harsh environment, and the INCONEL-X 750 spring promise the valve a long service life.

Dual Plate Wafer Check Valve API 594 DN250 10K
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The double-disc check valve, made of A395 D1, has excellent resistance to corrosion. Designed in accordance with API594, the check valve is connected to pipes with WAFER. This valve is eligible to be put in marine working conditions.

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150LB V ball valve Duplex Stainless Steel 4A
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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. 

BS 1868 Swing Type Check Valve
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PTFE Sleeved Plug Valve
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Stainless Steel Multiport Ball Valve
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Bellow Seal Globe Valve With Handwheel
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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.

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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.