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...

Ball Valve
加载中...

1-1/2" 150LB Lining Ball Valve FF CF8+PFA Lever GB/T12237-2007

1-1/2" 150LB ball valve is made according to GB/T12237-2007 standard. The valve body is made of CF8+PFA. It has the structural characteristics of fluorine lining. Its connection mode is FF. And it has Lever operation mode.

  • 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:

    CF8+PFA
  • Method of Operation:

    Lever
Inquiry now
Product Detail

Product Description

Type

Ball Valve

Size

1-1/2"

Pressure

150LB

Connection

FF

Operation

Lever

Body Material

CF8+PFA

Design Norm

GB/T12237-2007

Face to Face Length

HG/T3704-2003

Flange Dimensions

ASME B16.5

Test & Inspection Code

GB/T13927-2008

Applicable Medium

Water, Oil and Gas

Features

1. Extremely high chemical stability, suitable for any highly corrosive chemical medium;

2. The full floating ball valve structure is adopted to facilitate the ball sweeping and pipeline maintenance of the plumbing.

Technical Drawing

Dimension Checking

Pressure Testing

Nameplate & Packing

Inspection report

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
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.

JIS Globe Valve Flanged
Marine Bronze Globe Valve DN32 5K FF Flanged

The DN32 JIS 5K globe valve is suitable for marine application. The bronze globe valve is handwheel operated with FF flange. Quick Detail Type Marine Globe Valve Size DN 32 Design Pressure 5K Connection Type FF Flange Design Code JIS F7301 Face to Face JIS B2002 Body Material Bronze Trim Material Bronze Application Water, Oil, Gas Purchasing System Late delivery time become a common issue in 2018. However, Dervos keep more than 90% on-time delivery, so how do we achieve that? It owns our purchasing department.  How do we react to a delay crisis? -Visit the factory everyday and supervise on site -Initiate related resources, such as machining workshops and skilled workers to help on expediting production What benefits could we do for you by keeping on-time delivery? -Avoid penalty from end user -Accumulate reputation -Gain client’s trust FAQ 1. Do you have your own foundry or forge shop?  No, but we have an approved list of foundries over the past decade of casting inspections, which can make sure that our castings are of good quality and all the raw materials are traceable.  2. Can you do NDE Capability radiography, MT, UT, LP? Of course, we can do all these tests upon our clients, but there will be additional charge to these tests. 3. What kind of test will you do for each order? After valve assembly, we will do hydraulic test for shell & sealing and air test. Plus, we will do dimension checking (face to face dimension, flange dimension) as per assembly drawing and standards.

 Ductile Iron Gate Valve
Ductile Iron Gate Valve Non Rising Stem PN10 GGG50

The ductile iron gate valve has GGG50 body material and EPDM soft seat. The valve is designed with non-rising stem, RF connection and manual operation, used in fire water. Quick Detail Type Gate Valve Size DN300, DN400 Design Pressure PN10 Construction Non-rising Stem, Soft Seat ConnectionType Flange OperationType Handwheel Operation Body Material GGG50 TrimMaterial Stem 2Cr13, EPDM Seat Medium Water Origin China Hydrostatic Pressure Test Dimension Checking Packing

Lug Type, 2 600LB Dual Plate Wafer Check Valve, Body LCC
Lug Type, 2" 600LB Dual Plate Wafer Check Valve, Body LCC, API594

2" 600LB Dual Plate Wafer Check valve is made according to API594 standard. The valve body is made of A352 LCC+SS316. It has the structural characteristics of Dual Plate Wafer type and built-in type. Its connection mode is lug.

Double Eccentric Butterfly Valve
Body CF8M, 6" 150LBS High Performance Double Eccentric Butterfly Valve, Lug Connection, Lever, API609

6" 150LBS double eccentric butterfly valve is made according to API 609 standard. The valve body is made of A351 CF8M. It has the structural characteristics of double eccentric and high performance. Its connection mode is lug. And it has lever operation mode.

Butterfly Valve
26" 150LB High Performance Double Eccentric Butterfly Valve WCB API609

26" 150LB Butterfly valve is made according to API609 standard. The valve body is made of WCB. It has the structural characteristics of double eccentric, high-performance, bi-directional sealing, fireproof design and anti-corrosion turbine. Its connection mode is lug type. And it has turbine operation mode.

Floating Ball Valve
DN25 PN40 Floating Ball Valve A105 ISO17292 Lever EN1092-1 B1

DN25 PN40 ball valve is made according to ISO17292 standard. The valve body is made of ASTM A105. It has the structural characteristics of floating ball and full bore. Its connection mode is EN 1092-1 B1. And it has lever operation mode.

Gate Valve
Pressure Seal Gate Valve 10'' 1500LB WCC BW PSB

10'' 1500LB gate valve is made according to ASME B16.34 standard. The valve body is made of WCC. It has the structural characteristics of pressure self sealing, rising stem, elastic wedge and structural length of 864mm. Both ends of the valve stem are threaded. It has BW connection type.

Forged Steel Globe Valve
SW Connection, 1" 800LB Forged Steel Globe Valve, Body A105N, API602, Handwheel

1" 800LB forged steel globe valve is made according to API 602 standard. The valve body is made of A105N. It has the structural characteristics of bolt cover. Its connection mode is SW. And it has hand wheel operation mode.

SW Connection, 1'' 800LB Forged Steel Gate Valve, Body F304L, API602, Handwheel
SW Connection, 1'' 800LB Forged Steel Gate Valve, Body F304L, API602, Handwheel

1" 800LB forged steel gate valve is made according to API602 standard. The valve body is made of A182-F304L. It has the structural characteristics of bolt cover, rigid gate plate. Its connection mode is SW. And it has hand wheel operation mode.

Tilting Disc Check Valve
10" 150LB Tilting Disc Check Valve WCB Wafer API6D

10" 150LB tilting disc check valve is made according to API 6D standard. The valve body is made of A216 WCB+SS316. It has the structural characteristics of swash plate type. Its connection mode is wafer.

Flanged Stainless Steel Globe Valve OS&Y
Stainless Steel Globe Valve PN16 DN50 Flanged Handwheel

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

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