A check valve is a critical device that prevents backflow, widely used in water treatment, oil & gas pipelines, chemical processing, and steam systems. After long-term operation, check valves may experience issues such as leakage, vibration noise, or sticking. If not addressed promptly, these problems can reduce system efficiency and even cause equipment damage or safety hazards. So, how can you tell if a check valve needs replacement? Which faults can be repaired, and which require a full replacement? This article provides a systematic guide. 1. Basic Operating Principle of Check Valves The primary function of a check valve is to automatically prevent backflow. When fluid flows in the intended direction, the valve disc is pushed open by pressure; when flow reverses, the disc closes automatically, using either its own weight or a spring, preventing backflow. Common types include: Lift Check Valve Swing Check Valve Dual Plate Wafer Check Valve Ball Check Valve Although their designs vary, the key criteria for determining whether a check valve needs replacement remain the same: sealing performance, operational smoothness, and structural integrity. 2. How to Determine if a Check Valve Needs Replacement Visible Leakage (Internal or External) If fluid continues to flow backward when the valve is closed, it indicates significant wear or deformation of the sealing surfaces, preventing an effective seal. If the leakage exceeds system tolerances and cannot be corrected by cleaning or resurfacing, the valve or its sealing components should be replaced. Sticking or Inflexible Valve Disc After long-term operation, the valve stem, guides, or disc may become stuck due to scaling, corrosion, or debris. If cleaning, descaling, or lubrication fails to restore smooth operation, replacement is recommended. Excessive Noise or Vibration Frequent opening and closing or rapid disc rebound can cause vibration or knocking sounds. This is usually due to spring failure, loose valve components, or worn guides. Persistent or frequent noise should trigger inspection of the valve’s structural integrity and consideration for replacement. Corroded or Cracked Valve Body or Cover Exposure to acidic, alkaline, or high-temperature fluids can corrode or crack the valve body, compromising structural strength and posing safety risks. Such damage cannot be repaired and requires full valve replacement. Frequent Backflow or Abnormal System Pressure Fluctuations Poor sealing or delayed valve response can cause system pressure variations, including water hammer. If repeated adjustments do not resolve the issue, it indicates aging of the internal spring or disc mechanism, necessitating timely replacement. 3. Common Fault Diagnosis and Solutions Fault: Valve fails to close completely, causing backflow Cause: Worn sealing surfaces, deformed disc, or trapped debris Solution: Remove ...
If you’ve ever hesitated between choosing a flanged or threaded globe valve, you’re not alone. Globe valves are common shut-off valves widely used in industries such as oil and gas, chemical processing, power generation, shipbuilding, and water treatment. While both connection types can control fluid flow, they differ significantly in terms of installation method, sealing performance, and suitable applications. This article will provide a systematic comparison of flanged and threaded globe valves from the perspectives of structure, performance, and application. I. Fundamental Difference in Connection Methods 1.Flanged Globe Valve A flanged globe valve connects to the pipeline through flanges, with bolts tightening the flange faces together to ensure a secure seal.This connection type offers excellent strength and reliability, making it ideal for medium to high-pressure, large-diameter, and frequently operated systems.In industrial applications, typical sizes range from DN50 to DN300, and flange dimensions generally follow international standards such as ANSI, DIN, or JIS. 2. Threaded Globe ValveA threaded globe valve typically uses either internal (NPT/BSP) or external threads to connect to the pipeline, relying on the threads themselves for sealing.This compact and lightweight structure allows for easy installation and is mainly used in small-diameter (usually ≤ DN50) and low-pressure systems, including residential pipelines.Because it does not require welding or flange gaskets, a threaded valve is more cost-effective in both installation and maintenance. II. Comparison of Sealing Performance and Maintenance Flanged Globe ValveFlanged globe valves typically use metal or flexible graphite gaskets for sealing, offering excellent resistance to high temperature, high pressure, and corrosion.During long-term operation, maintenance or valve replacement is straightforward—simply loosen the flange bolts to disassemble the valve. Threaded Globe ValveThe sealing of a threaded globe valve mainly depends on the thread engagement and sealing materials such as PTFE tape or sealing paste.However, repeated disassembly can damage the threads and increase the risk of leakage.For this reason, threaded globe valves are better suited for fixed installations, clean fluids, and low-pressure systems. III. Structural Dimensions and Installation Requirements Flanged Globe ValveFlanged globe valves are larger in size and require more installation space, but they provide superior vibration resistance and pressure tolerance.They are commonly used in industrial piping networks or pump station systems where sufficient structural support is available. Threaded Globe ValveThreaded globe valves feature a compact design, making them ideal for confined spaces or lightweight piping systems such as laboratories, compressor inlets and outlets, and domestic water supply lines.However, thr...
The global industrial valve market is undergoing a quiet yet significant transformation. Growth is no longer driven mainly by new construction projects — instead, it’s increasingly fueled by the replacement and modernization of aging equipment and infrastructure. From petrochemical plants to municipal water systems and natural gas pipelines, valve upgrades have become a key priority across industries. Aging Equipment Drives Rising Valve Replacement Demand In many industrial facilities, valves—though seemingly durable—gradually suffer from seal wear, sluggish operation, and leakage after years of service. For plants operating over a decade, valve degradation has become a major factor affecting safety and efficiency. With stronger focus on maintenance, process safety, and energy efficiency, end users in oil & gas, power, and water treatment sectors are accelerating valve replacement and upgrade projects. This trend aligns with a global shift toward predictive maintenance and sustainable operations, increasing demand for ball valves, gate valves, and control valves. Market research from Mordor Intelligence and others shows a shorter valve replacement cycle due to rising maintenance costs and downtime risks. Stricter environmental and safety standards are also pushing faster modernization worldwide. In the U.S., for example, the water sector—with pipelines averaging over 40 years old—is investing in large-scale valve renewal programs to reduce leakage and unplanned shutdowns. Similar initiatives are emerging across Europe and Asia. Infrastructure Investment Fuels Market Expansion Beyond replacements, ongoing infrastructure investment continues to drive valve demand globally. Asia’s rapid industrial growth and the Middle East’s refining and petrochemical expansion have led to increased valve procurement. According to GMI Insights, the global industrial valve market reached USD 75.9 billion in 2024 and is projected to hit USD 142.6 billion by 2034 (CAGR: 6.6%). Precedence Research forecasts even higher potential—up to 12.5% CAGR. This growth is backed by large-scale upgrades in urban water networks, wastewater treatment plants, natural gas pipelines, and energy transition projects such as hydrogen and carbon capture systems, all requiring next-generation high-performance valves. Valve Replacement Becomes a Smart Technology Upgrade Modern valves are evolving beyond mechanical parts. With smart manufacturing and the Industrial Internet of Things (IIoT), today’s valves feature sensors, smart actuators, and remote monitoring. Engineers can now track performance in real time and conduct predictive maintenance, reducing unexpected downtime. Advanced materials like corrosion-resistant alloys, cryogenic steels, and special polymers are extending service life and reliability—especially in harsh environments. For indu...
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.
Payment:
30% when order confirmed, 70% before shipmentProduct Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai, ChinaLead Time:
30~60 days Ex Works after order confirmationMaterial:
ASTM A216 WCBMethod of Operation:
Turbine OperationProduct Description
|
Type |
Butterfly Valve |
|
Size |
20" |
|
Pressure |
150LB |
|
Connection |
Lug |
|
Operation |
Turbine Operation |
|
Body Material |
ASTM A216 WCB |
|
Design Norm |
API 609 |
|
Face to Face Dimension |
ASME B16.10 |
|
Flange Dimension |
ASME B16.5 |
|
Test & Inspection Code |
MFR |
|
Temperature |
-29 ~ 180°C |
|
Applicable Medium |
Acid, Alkali, Salt, etc. |
Features
1. Modular design, convenient for maintenance and replacement, and cost saving;
2. Effectively eliminate leakage and make the valve achieve the best sealing effect.
Technical Drawing
Dimension Checking
Pressure Testing
Painting
Nameplate & Packing
Inspection report
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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. 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.
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.
The swing type check valve, designed with PN40 RF flange, bolted cover, is made of cast steel 1.0619 and ss316 trim material. The full bore check valve can be manufactured per client's special requests. Quick Detail Type Non Return Valve ( Check Valve) Nominal Size DN 150 NominalPressure PN 40 Construction BB, Swing Type Disc, Exnternal Pin Connection Raised Face Flange Design & Manufacture DIN 3356 End to End EN 558 Connection EN 1092 Test & Inspection EN 12266 Body Material GS-C25 (1.0619) ApplicableTemp -29℃~+425℃ Media W.O.G. Material No Part Name Carbon steel to ASTM Alloy steel to ASTM Stainless steel to ASTM WCB LCB WC6 WC9 C5 CF8 CF8M CF3 CF3M 1 Body A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Seat Ring A105 A350 LF2 A182 F11 A182 F22 A182 F5 A182 F304 A182 F316 A182 F304L A182 F316L 3 Disc nut A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 4 Disc washer A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 5 Disc A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 6 Hinge A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 7 Hinge pin A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 8 Yoke A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 9 Bonnet nut A194 2H A194 4 A194 7 A194 8 10 Bonnet bolt A193 B7 A193 L7 A193 B16 A193 B8 11 Gasket Stainless Steel Spiral Wound graphite or Stainless Steel Spiral Wound PTFE 12 Cover A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 13 Hook screw Steel 14 Name Plate Stainless steel or Aluminum 15 Rivet Stainless steel or Aluminum Other Material ( Alloy 20, ANSI 321, Monel Hastelloy, etc)are available on request Our Service A good customer service is as valuable as product itself. In Dervos, we will offer a full range of customer service to make you feel easy when doing business with us. Providing weekly production report When production begins, you will get production report weekly, so that you can have good command of product status and report to your customer at the meantime. Offering warranty of 18 months 18 months warranty period will be offered after shipment, no concern to purchase valve from Dervos. Providing solutions within 3-days for complaints All the complaints will be solved within 3 days, in this case, you can timely reply and solve problems for your customer, to relax them even when complaints happening.
DN50 PN40 check valve is made according to API 594 standard. The valve body is made of A105. It has the structural characteristics of dual plate and wafer type. Its connection mode is wafer.
12" 600LB 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-shaped, body cover bolt connection. Its connection mode is RF.
The 3 way T type ball valve owns flange connection, gearbox, ss304 body, ball and stem. The 3 inch flanged ball valve features in its T type three way ports which could connect any pair of ports or three ports together. Quick Detail Type Ball Valve Size 3" Pressure ANSI 300 Construction Three Way Ball Valve Connection Flanged Connection Operation Mode Gearbox Body Material A182 F304 Manufacture and Design API 6D Pressure & Temp ASME B16.34 End to End Code ASME B16.10 End Connection ASME B16.5 Inspection API 6D, API 598 Temperature Range -29℃~+200℃ Medium WOG Related Knowledge What is the difference between T port and L port 3-way ball valve? Normally speaking, 3-way ball valve can be divided into T type and L type. A T port three-way ball valve can connect any two ports, and even connect all three ports together at the same time. However, an L port three-way ball valve can only connect the center port with either side port or disconnect three ports. FAQ 1. Can the orders always be delivered on time? Our purchasing team follows up very closely with each order to make 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 can even be shortened to 20~25 days. We believe the short lead time can make our offer more competitive and help you secure more orders. 3.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.
6" 150LB basket strainer is made according to ASME B16.34 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of basket style, bolted cover, with exhaust and drain plugs. Its connection mode is RF.
The 16 inch triple offset butterfly valve is designed with metal seat, stainless steel CF8M body, disc and stem. The fully lugged butterfly valve with gearbox has Class 150 design pressure as per API 609. Design Feature 1. Small volume, light weight, simple structure 2. Multi-layer metal seated/fully metal seated 3. Firesafe design 4. Anti-blowout stem 5. Small torque value for operating easily 6. Reliable sealing and could meet zero leakage requirement 7. With function of regulating flow 8. Triple eccentric design for minimized wear of sealing face Quick Detail Type Butterfly Valve Size 16'' Pressure ANS 150 Structure Triple Eccentric, Triple Offset, Metal Seated Connection Type Lug Type Operation Gearbox Operated Design Code API 609 Face to Face ASME B16.10 End Connection ASME B16.5 Test & Inspection API 598 Body Material A351 CF8M Temperature Range -29℃~+425℃ Application Water, Oil, Gas Material No Part Name Carbon steel to ASTM Alloy steel to ASTM Stainless steel to ASTM WCB WC6 WC9 C5 CF8 CF8M CF3 CF3M 1 Body A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Below Axle Bush PTFE or Stainless Steel and Graphite Spiral Wound 3 Stem A182 F6 A182 F304 A182 F304 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 4 Seat Ring F6 Stellite 6 Stellite 6 Stellite 6 A182 F304 A182 F316 A182 F304L A182 F316L 5 Butterfly Plate A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 6 Lock Ring A105 A182 F22 A182 F22 A182 F22 A182 F304 A182 F316 A182 F304L A182 F316L 7 Pin Carbon Steel or Alloy Steel 8 Screw Carbon Steel or Alloy Steel 9 Top Axle Bush PTFE or Stainless Steel and Graphite Spiral Wound 10 Packing Graphite+SS304 11 Bolt A193 B7 A193 B7 A193 B7 A193 B7 A193 B8 A193 B8 A193 B8 A193 B8 12 Nut A194 2H A194 2H A194 2H A194 2H A194 Gr.8 A194 Gr.8 A194 Gr.8 A194 Gr.8 13 Bolt A193 B7 A193 B7 A193 B7 A193 B7 A193 B8 A193 B8 A193 B8 A193 B8 14 Nut A194 2H A194 2H A194 2H A194 2H A194 Gr.8 A194 Gr.8 A194 Gr.8 A194 Gr.8 15 Yoke A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 16 Gland A182 F6 A182 F304 A182 F304 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L
2" 800LB swing check valve is made according to API 602 standard. The valve body is made of ASTM A105N. It has the structural characteristics of bolted cover, swing type. Its connection mode is NPT.
14" 150LBS swing check valve is made according to BS 1868 standard. The valve body is made of ASTM A216 WCB+STL. It has the structural characteristics of plug cover and swing type. Its connection mode is RF.
The DN150 PN10 unidirectional knife gate valve features a single piece, stainless steel body design provides tested performance in applications ranging from general purpose to severe media.
2" 150LB inverted pressure balanced lubricated plug valve is made according to API 6D standard. The valve body is made of A216 WCB. It has the structural characteristics of short structure, inverted oil seal, body valve seat. Its connection mode is RF. And it has lever operation mode.
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