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.
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.
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...
Payment:
30% T/T When Order, 70% T/T Before ShipmentProduct Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai ChinaLead Time:
35~60 days Ex Works After Order ConfirmationMaterial:
Cast IronMethod of Operation:
Hand WheelThe 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
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The DN80 PN16 cast iron gate valve has face to face dimension as per DIN3202 F4 or DIN3202 F5. This GG25 gate valve is designed with resilient seat, non rising stem, bb, RF flange, suitable for water treatment application. Quick Detail Type Gate Valve Nominal Diameter DN 80 Nominal Pressure PN 16 ConstructionType Non-rising stem, Bolted Bonnet, Resilient Seat ConnectionType Flanged OperationType Handwheel Operation Body Material Cast Iron GG25 TrimMaterial Cast Iron Wedge, SS420 Stem, EPDM Seat Design Code DIN 3352 End to End Code DIN 3202 Flange Dimesion DIN 2501 Medium Water Origin China Design Feature 1.Resilient seat for good sealing performance 2.Low flow resistance and small pressure drop 3.Non-rising stem for installation space is limited 4.No limitation for flow direction of medium 5.Epoxy painting available for internal and external part of the valve for anti corrosive function Company Brief Introduction Specializing in valve industry over 10 years, Dervos becomes the leading vendor of gate, globe, check, ball, butterfly, plug valves and strainers. We serve oil and gas user such as LUKOIL, MOL, YPF with local partners. Dervos show its advantages in: 1. Our partnerships with tens of stable suppliers allow us to provide customers with a wide range of high-quality products at a competitive price. 2. Each order is under strict quality control with inspection reports before delivery. 3. We value delivery time as much as our customers do. With the powerful purchasing system, we follow each order closely to secure on-time delivery. 4. One-stop solutions will be offered in a timely manner
The gate valve is made of ductile iron GGG50 . The valves disc is rubber-packed to get excellent sealing effect by the rubber's resilient deformation. Non-rising resilient seated gate valves solve the problem in general gate valves such as leakage, rusting etc. And it also saves space.
DN800 PN10 gate valve is made according to DIN standard. The valve body is made of GGG50. It has the structural characteristics of F4 drinking water soft gate. Its connection mode is RF, and it has gear operation.
8" 2500LB DBB Trunnion Mounted Ball valve is made according to API 6D standard. The valve body is made of A182 F51. It has the structural characteristics of DBB Fixed Ball Valve, Full Bore, Fireproof/Electrostatic/Anti-Exposed Stem Design, Compliant with NACE MR0175. Its connection mode is RTJ. And it has Turbine operation mode with locking device.
DN80 PN40 globe valve is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.0619. It has the structural characteristics of bolted cover and straight through type. Its connection mode is EN1092-1 B. And it has hand wheel operation mode.
The 4 inch cryogenic ball valve, designed as per API609, has many parts equipped RPTFE --It has the lowest coefficient of friction and the best corrosion resistance of any known plastic material, so that the valve can handle quite extreme situations.
8”300LB Cast Steel Y Type Strainer is made according to ASME B16.34 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of Y Type. Its connection mode is RF.
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
The bellows seal globe valve adopts the bellows seal design, which completely eliminates the shortcomings of the normal valve stem packing seal aging and easy to leak, not only improves the energy efficiency, increases the safety of the production equipment, reduces the maintenance cost and frequent maintenance. It also provides a clean and safe working environment.Its simple structure and the low price makes it almost no "competitors". Quick Detail Type Globe Valve Norminal Size 1.5 Inch NorminalPressure 150LB Construction Bolted Bonnet, Outside Screw & Yoke, Rising Stem, Bellow Seal ConnectionType RF Flange Operation Handwheel Design Code ASME B16.34, API 602 Face to Face ASME B16.10 Flange End ASME B16.5 Test & Inspection API 598 Body Material ASTM A105 ApplicableTemp -29℃~+425℃ Application Water, Oil, Gas Structure Feature 1. Double seal design (corrugated pipe + packing). If the bellows fails, the stem packing will also be avoided; 2. External leakage, and in line with international sealing standards; 3. No fluid loss, reduce energy loss, and improve plant equipment safety; 4. Long service life, reduce the number of maintenance, reduce operating costs; 5. Rugged bellows seal design, ensuring zero leakage of the valve stem, providing maintenance-free conditions. Technical Drawing Dimension Our Service Dervos customer service is one of our biggest competitive advantages. In Dervos, we provide- 1.Quotation within 24 hours or no later than 3 days This will let you meet the quotation submission deadline and enhance your working efficiency 2.Weekly status report of your order In this way, you will have a clear picture of your order. You do not need to waste time on pushing us for status update 3.An 18-month warranty period A warranty certificate will issued after shipment and you will not have any concern after buying valves. 4.Solutions to complaints within 3 days Quick and responsible actions to complaints will protect your reputation and reduce the financial loss as much as possible.
The swing check valve is made of 1.0619, a kind of carbon steel, as per DIN standard.The check valve is DN80 and PN40, or 3 inch and 300LB. And the valve is capable in working temperature between -19 to 425 degree Celsius.
Quick Detail Type Globe Valve Size DN15 DesignPressure PN160 Construction Tee Pattern Connection Socket Welded Design & Manufacture BS5352 Socket Weld ANSI B16.11 Test & Inspection EN12266 Body Material A182 F5+STL Trim Material A276 410; STL Media WOG Description --Tee Pattern is the most common type of globe valve with a z shaped diaphragm. --The seat is oriented horizontally allowing the stem and disk to travel perpendicular to the horizontal line. This alsocontribute to low flow coefficient and higher pressure drop. Features --Good shutoff capability --Moderate to good throttling capability --Shorter stroke (compared to a gate valve) --Available in tee,WYE, and angle patterns, each offering unique capabilities --Easy to machine or resurface the seats --With disc not attached to the stem, valve can be used as a stop-check valve Technical Drawing Dimension Check Witnessing Tests Nameplate & Packing FAQ 1.Can the ordersalways be delivered on time? Our purchasingteam follows up very closely with each order tomake sure on-time delivery for most of orders. In 2018,more than 90% orders were delivered on time, and we are dedicated to doing better. 2.What’s the normal delivery lead time? For normal material, usually the delivery time is about 35~40 days, and for forged material, the delivery canevenbe shortened to 20~25 days. We believe the short lead time can make our offer more competitive and help you secure more orders. Do you have different price levels for us? With our numerous suppliers, different price levels are available with us, so we are able to help you win more customer from different markets requesting for high, medium and low prices. About Dervos Xiamen Dervos Valves Industry Co.,Ltd (stock code 861601), founded in June 2008, is a one-stop industrial valves supplier integrated of R&D, manufacture, resource integration, and trade service. For 12 years, Dervos has been committed to finding solutions for industrial needs and providing professional service for both general and specialized valves.
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