English

English

Get a Quote
Products

Hot Products

Company News

When Should a Check Valve Not Be Used?
When Should a Check Valve Not Be Used?
2025-09-26

Have you ever encountered repeated fluid shocks, frequent valve cycling, or excessive noise in your pipeline system? If a check valve is not selected properly, issues such as leakage, valve damage, or fluid hammer can occur. While check valves are effective at preventing backflow, they are not suitable for all operating conditions. The following cases require special attention:   High-frequency opening and closing conditions Check valves rely on the disc or flap to close automatically. If the medium in the pipeline flows frequently or the valve cycles too often, impact, water hammer, or vibration may occur, shortening the valve’s service life. In such cases, consider using spring-loaded or damped check valves, or even other valve types better suited to the application.   High-viscosity fluids or media with solid particles Thick fluids or those containing solids can prevent the valve disc from closing fully, increasing the risk of leakage. For slurries, mud, or liquids with a high concentration of particles, specialized valves or additional filtration equipment should be used instead.   High-pressure systems In high-pressure applications, the valve disc is subject to strong impacts and repeated collisions, which can cause wear on the sealing surfaces or structural damage. For such environments, more robust backflow prevention solutions should be considered.   Systems Sensitive to Pressure or Flow Variations When a check valve closes, it may cause pressure loss or flow fluctuations. If the system is highly sensitive to such variations, careful evaluation of the valve type and installation location is required to avoid negative impacts on overall pipeline performance.   Conclusion A check valve is an essential device for preventing backflow, but it should be used with caution in certain operating conditions such as high-frequency cycling, high-viscosity fluids, high-pressure systems, or applications sensitive to flow variations. By properly assessing the pipeline operating conditions and fluid characteristics, you can ensure the check valve performs at its best, extends service life, and reduces maintenance costs.

What Are the Types of Disc Designs in Globe Valves?
What Are the Types of Disc Designs in Globe Valves?
2025-09-18

Have you ever faced the challenge of selecting the right globe valve disc during pipeline system design or operation? When using a globe valve to control fluid flow, the disc type directly affects sealing performance, flow regulation, and suitability for specific conditions. Understanding the types of discs and their applications can help you make faster, more accurate selections and improve overall system efficiency.   Flat / Standard Disc   Features: The disc has a flat sealing surface, simple structure, and relatively low manufacturing cost. Applications: Commonly used for water, steam, air, and other low-viscosity media. Suitable for medium to low-pressure systems.   Pros & Cons: Provides basic and reliable shutoff, but sealing reliability is moderate. Under long-term high pressure or high temperature, the sealing surface may wear more quickly.   Conical / Tapered Disc   Features: The disc is conical in shape, matching the sealing surface of the valve seat with a smaller contact area. Applications: Ideal for high-pressure conditions or systems requiring precise shutoff, such as steam and oil pipelines. Pros & Cons: Offers excellent sealing performance, but requires greater operating torque for opening and closing.     Plug / Concave Disc   Features: The disc surface is slightly convex, forming point contact with the valve seat, offering high sealing precision. Applications: Suitable for gases, liquids, and some corrosive media, allowing effective flow regulation.   Pros & Cons: Manufacturing cost is higher, but sealing performance and wear resistance are superior to flat discs.   Double Disc   Features: A large disc contains a smaller inner disc. Applications: Commonly used in high-pressure, large-diameter valves. It helps balance pressure and extend valve service life. Pros & Cons: Structurally more complex and more expensive, but ideal for high-pressure, large-diameter applications.     Conclusion     Globe valve discs come in a variety of types, each with unique advantages and suitable working conditions. When selecting a disc, consider the medium type, pressure, temperature, and flow requirements. Choosing the correct disc ensures reliable system sealing, extends valve life, and reduces maintenance costs.

Which Inspection Reports Must Be Requested from the Supplier When Purchasing Gate Valves
Which Inspection Reports Must Be Requested from the Supplier When Purchasing Gate Valves
2025-09-12

If you have ever experienced project delays due to valve quality issues, or are in the process of selecting qualified valve suppliers for an upcoming industrial project, then understanding the essential inspection reports required when purchasing gate valves becomes critically important. As a key control component in piping systems, the quality of a valve directly affects the safety and reliability of equipment operation. Therefore, when purchasing gate valves, buyers should not only focus on price and delivery time but also ensure that the supplier can provide complete inspection reports.   Mandatory Inspection Reports   ● Material Test Report (MTR) Purpose: To verify that the main components of the valve, such as the body, bonnet, and stem, meet the specified material standards (e.g., ASTM, DIN, EN). Importance: Prevents valve failure under corrosive or high-pressure conditions due to substandard materials.   ● Pressure Test Report Hydrostatic Test: Checks the valve’s strength under the specified pressure. Air Tightness Test: Ensures the valve does not leak at operating pressure. Importance: Confirms that the valve meets the required design pressure rating.   ● Dimension Inspection Report Content: Verifies whether valve structural length, flange dimensions, wall thickness, etc., comply with design and standards (ANSI, EN, GB). Importance: Ensures proper alignment with the piping system and prevents installation deviations.   ● Non-Destructive Test (NDT) Report Methods: Includes Ultrasonic Testing (UT), Radiographic Testing (RT), Magnetic Particle Testing (MT), and Penetrant Testing (PT). Importance: Verifies that castings or welds are free from internal defects, enhancing the valve’s long-term operational reliability.   ● Coating & Painting Test Report Content: Checks paint thickness, adhesion, hardness, salt spray resistance, etc. Importance: Ensures the valve has strong corrosion resistance for outdoor, marine, or chemical environments.   ● Final Inspection Report Content: Includes comprehensive records of appearance, operational performance, markings, packaging, and other inspection items. Importance: Demonstrates that the valve has undergone strict quality control before delivery.   Conclusion   When purchasing gate valves, requiring suppliers to provide complete inspection reports is not only a verification of product quality but also a guarantee of overall project safety and reliability. By reviewing these reports, customers can reduce operational risks, lower maintenance costs, and extend the service life of their equipment.   Q&A   Q1: Why is a Material Test Report (MTR) mandatory when purchasing gate valves? A1: Material determines the valve’s pressure resistance, corrosion resistance, and service life. Different operating conditions require specific materials, so an MTR is necessary to verify compliance.   Q2: Is Non-Destructive Testing (NDT) require...

Cast Iron Concentric Butterfly Valve PTFE Lined
加载中...

PTFE Lined Flanged Butterfly Valve 14 Inch Gearbox

  • Payment:

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

    China
  • Color:

    Customization
  • Shipping Port:

    Shanghai China
  • Lead Time:

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

    Ductile Iron Butterfly Valve
  • Method of Operation:

    Manual Butterfly Valve, Gearbox Operation Butterfly Valve
Inquiry now
Product Detail
The PTFE fully lined butterfly valve is made of cast iron body and with gearbox operation. The 14 inch flanged valve has concentric type structure.


Quick Detail

Type

Butterfly Valve

Size

14''

Design Pressure

150LB

Construction

Concentric Type, PTFE Lined

Connection Type

Double Flanged

Operation

Gear Operated

Design Code

API 609

Face to Face

ASMEB16.10

End Connection

ASMEB16.5

Test & Inspection

API 598

Body Material

Cast Iron GGG40

Temperature Range

-15℃~+150℃

Application

Water, Oil, Gas


Related Knowledge
What is the advantage of fully lined butterfly valve?


The main advantage of lined butterfly valve is that it can handle abrasive and corrosive application at a relatively lower cost.


The PTFE or PFA flexible seat provide a zero leakage sealing performance.


Plus, the lined material PTFE has strong corrosion resistance, stable performance, low friction coefficient, which make the lined butterfly valve has a long service life.

Double Flanged Butterfly Valve Manufacturers


How does Dervos control quality of raw material?
Raw material plays an important role in product quality. Likewise, casting and forging affect valve quality a lot. That is why Dervos pay a lot of attention to foundries. We have an approval list of foundries and classify them by certificates, scale, process and materials. To meet different requirements from customers, we could even appoint suitable foundries for our customers.

Dervos Approval List of Industrial Valve Foundries


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
API609 PFA Lined Butterfly Valve LUG FF 20”150LB
API609 PFA Lined Butterfly Valve LUG FF 20”150LB

This 20 inch butterfly valve is plastic lined type one. Its PFA lined disc and its PTFE seat ring enable it a excellent corrosion resistant performance. With a gearbox, it is easy to drive.

Butterfly Valve
20" 150LB Lined Butterfly Valve API 609 Lug ASME

20" 150LB butterfly valve is made according to API 609 standard. The valve body is made of WCB. Its connection mode is Lug. And it has turbine operation mode.

1 1/2 inch pressure-sealed globe valve 1500LB SW OSY
1 1/2 inch pressure-sealed globe valve 1500LB SW OSY

The 1 1/2inch 1500LB globe valve,made of one kind of alloy steel F22, is the best answer to working conditions under high pressure and temperature .

Globe Valve
6" 300LB Cast Steel Globe Valve WCB RF BS1873

6" 300LB globe valve is made according to BS1873 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of straight through, rising stem. Its connection mode is RF. And it has gearbox with lock operation mode.

Swing check valve
API 6D WCB RF Swing Type Check Valve CL600 4 inch 6 inch

API6D swing type check valve RF connnection bolted bonnet full pore WCB body, WCB+13Cr disc, A105+13Cr seat ring, WCB hinge. Suitable temperature in -29℃~+425℃ Quick Detail Type Swing Check Valve Size 4 inch-6 inch Design Pressure CL600 Construction BC, Swing type ConnectionType Flange OperationType - Body Material WCB DiscMaterial WCB+13Cr Hinge Material WCB Seat Material A105+13Cr Design Code API 6D Face to Face Dimension ASME B16.10 Test and Inspect API 598 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China

DN200 PN16 Bellow Seal Globe Valve, RF, Body 1.4408
DN200 PN16 Bellow Seal Globe Valve, RF, Body 1.4408, EN13709

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.

Butterfly Valve
10" 150LB Concentric Butterfly Valve Lug GGG40 API609 Lever

10" 150LB butterfly valve is made according to API 609 standard. The valve body is made of GGG40. It has the structural characteristics of medium line type and lug type (threaded hole). Its connection mode is lug. And it has lever operation mode.

10 300LB Alloy Steel Gate Valve RF C5 API600 Bevel Gear
10" 300LB Alloy Steel Gate Valve RF C5 API600 Bevel Gear

10" 300LB gate valve is made according to API 600 standard. The valve body is made of ASTM A217 C5. It has the structural characteristics of bolt cover, elastic gate, rising stem, OS&Y, full bore and body valve seat. Its connection mode is RF (125~250AARH). And it has bevel gear operation mode.

Triple Eccenctric Butterfly Valve
14in 150LB Triple Eccentric Wafer Butterfly Valve Gearbox Soft Seal

WCB 14inch 150LB Butterfly Valve Triple Eccentric Un-directional Seal Wafer Type Gear Handwheel Operation WCB Body WCB Disc F6a Stem PTFE Seal Ring 13Cr Overlay on Seat. Design and Manufacture API 609. Face to Face Dimension API 609. Flange and Dimension ASME B16.5. Test and Inspection API 598. Quick Detail Type Butterfly Valve Size 14” Pressure 150LB Construction Triple Eccentric Connection Wafer Operation Mode Gearbox Body Material A216 WCB Trim Material Ball/Stem F6a, Seat PTFE Design & Manufacture API 609 Pressure & Temp Code ASME B16.34 End to End ASME B16.10 End Connection ASME B16.5 Inspection API 598 Temperature Range -29℃~+200℃ Medium Oil, Water, Gas

Monel Globe Valve
3" Class300 Monel Globe Valve RF HF Acid Hand Wheel

3" class300 globe valve is made according to BS1873 standard. The valve body is made of Monel. Its connection mode is RF. And it has hand wheel operation mode.

Cast Steel Slab Gate Valve
RTJ Connection, 12" 1500LB Cast Steel Slab Gate Valve, Body WCB, Gearbox Operation

12" 1500LB cast steel slab gate valve is made according to API 6D standard. The valve body is made of A216 WCB. It has the structural characteristics of body cover bolt, full flow, cleanable pipe, anti-fire design. Its connection mode is RTJ. And it has gearbox operation mode.

Butterfly Valve
DN250 PN10 Three Eccentric Butterfly Valve Wafer WCB EN593 Turbine

DN250 PN10 butterfly valve is made according to EN593 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of three eccentricities, bidirectional one to one pressure test. Its connection mode is wafer. And it has turbine operation mode.

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