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...
2" 150LB gate valve is made according to API 600 standard. The valve body is made of A351 CF3. It has the structural characteristics of bolt cover, rising stem bracket. Its connection mode is RF. And it has handwheel 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:
A351 CF3Method of Operation:
HandwheelProduct Description
|
Type |
Gate Valve |
|
Size |
2" |
|
Pressure |
150LB |
|
Connection |
RF |
|
Operation |
Handwheel |
|
Body Material |
A351 CF3 |
|
Design Norm |
API 600 |
|
Face to Face Dimension |
ASME B16.10 |
|
End Connection |
ASME B16.5 RF |
|
Test & Inspection Code |
API 598 |
|
Temperature |
-29 ~ 425 °C |
|
Applicable Medium |
Water, Oil and Gas |
Features
1. Compact structure, simple structure, compact appearance, easy assembly, and reliable operation;
2. Flexible switch, easy to open and close operation.
Technical Drawing
Dimension Checking
Pressure Testing
Nameplate & Packing
Inspection report
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The stainless steel CF8M gate valve is designed with flange connection and handwheel operation per DIN 3352. The PN16 DN200 full port gate valve has OS&Y structure, resilient wedge and replaceable seat. Design Specifications Design and Manufacture: DIN 3352 End to End Dimension: DIN3202 Flange End: EN1092-1 Test & Inspection: EN12266-1/2 Design Feature -Full Bore Design -Superior flow rates & small friction loss -Low torque value for closing and opening the valve -Flexible wedge for better seating and ease of operation -Smooth finish and superior sealing for seat face -Every valve is manufactured with specific number on body for traceability Quick Detail Type Gate Valve Size DN 200 Pressure PN 16 Construction Bolted Bonnet, Rising Stem, Outside Screw and Yoke Connection Flange Connection Operation Handwheel Body Material Stainless Steel CF8M TrimMaterial Stainless Steel Temperature Range -268℃~+648℃ Medium Water, Oil and Gas Origin China Dervos Packaging Packaging is an important part we could never neglect. Dervos has a packaging process for each order to ensure a safe and clear delivery of the order.
4" 150LB gate valve is made according to API 603 standard. The valve body is made of ASTM A351 CF8M+STL. It has the structural characteristics of bolt cover, elastic wedge and rising stem. Its test and inspection conform to API 598, and its operation mode is handwheel operation.
DN200 PN40 gate valve is made according to EN1984 standard. The valve body is made of 1.4571+STL. It has the structural characteristics of bolt cover, elastic gate, rising stem and bracket. Its connection mode is EN1092-1/B. And it has hand wheel operation mode.
DN125 PN16 gate valve is made according to DIN 3352 standard. The valve body is made of 1.4408. It has the structural characteristics of bolt cover, rising stem, elastic wedge, with SS316 insulation jacket and structural length of 325mm. Its connection mode is RF EN1092-1 B1. And it has hand wheel operation mode.
DN100 PN40 5A Duplex Stainless Steel Gate Valve is made according to EN 1984 standard. The valve body is made of ASTM A995 5A+STL. It has the structural characteristics of Full Bore, Bolted Bonnet, Rising Stem with Yoke, Flexible Wedge. Its connection mode is EN1092-1 B1. And it has hand wheel operation mode.
Quick Detail Type Globe Valve Nominal Size NPS 2 NominalPressure Class 300 Construction BB, Rising Stem, Integral Seat Connection Type Flange Operation Type Handwheel Design Code BS1873 Face to Face ASME B16.10 Flange End ASME B16.5 Test & Inspection API 598 Body Material WCB+STL Trim Material F316+STL Temperature Range -29℃~425℃ 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 Technical Drawing Dimension Check Witnessing Tests Packing 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. Certificates Dervos could provide reports upon clients’requests, such as ISO 9001, PED CE, EAC, API 607, API 6D, API 6A and etc.
The 2 piece type floating ball valve has full port, fire safe design, anti blowout stem, ANSI 150 flange and lever operation. The carbon steel ball valve is designed with A216 WCB body, F316 stem and ball, PTFE soft seat. Quick Detail Type Ball Valve Size 4" Pressure 150 LB Construction Floating Type Ball, Two Piece Body, Full Bore Connection Raised Face Flange End Operation Wrench Operation Body Material Cast Steel WCB Trim Material SS316 &PTFE Design Standard API 6D Pressure & Temp Code ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.5 Inspection Code API 6D Temperature Range -29℃~+125℃ Media Water, oil and gas Material & Dimension No Part Name Carbon steel to ASTM Stainless Steel to ASTM WCB LCB CF8 CF8M CF3 CF3M 1 Body A216 WCB A352 LCB A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Bonnet nut A194 2H A194 4 A194 8 3 Bonnet bolt A193 B7 A320 L7 A193 B8 4 Cap A216 WCB A352 LCB A351 CF8 A351 CF8M A351 CF3 A351 CF3M 5 Gasket SS Spiral Wound/graphite or SS Spiral Wound/PTFE 6 Ball A105/Ep.Cr or F6 A182 F6 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 7 Seat Ring RPTFE or POM 8 Small spring Stainless Steel 9 Small ball A182 F304 A182 F316L 10 Stem A182 F6 A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 11 Stem Seat PTFE 12 Stem Packing PTFE or Graphite 13 Gland A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 14 Gland Bolt A193 B7 A193 B8 15 Galnd Flange A216 WCB A351 CF8 16 Positioning Plate Steel 17 Wrentch A216 WCB The material is according to ASTM standard CLASS 150 DN mm 15 20 25 40 50 65 80 100 150 200 250 NPS in 0.5 0.75 1 1.5 2 2.5 3 4 6 8 10 L (RF) mm 108 117 127 165 178 191 203 229 394 457 533 in 4.25 4.6 5 6.5 7 7.5 8 9 15.5 18 21 L1 (BW) mm 140 152 165 190 216 241 283 305 457 521 559 in 5.5 6 6.5 7.48 8.5 9.5 11.13 12 18 20.5 22 L2 (RTJ) mm 119 129.7 139.7 178 191 203 216 241 406 470 546 in 4.69 5.11 5.5 6.9 7.5 8 8.5 9.5 16 18.5 21.5 H mm 66 74 87 105 132 152 182 215 250 285 495 in 2.6 2.9 3.48 4.2 5.28 6.08 7.28 8.6 10 11.4 19.5 Do(W) mm 130 130 160 230 400 400 600 850 1100 1500 *350 in 5.1 5.11 6.3 9 15.74 15.74 23.62 33.46 43.3 59 13.8 RF(Kg) 2.3 3 4.5 7 15 20 25 40 97 160 240 BW(Kg) 2.0 2.5 3.8 5.8 12 17 21 36 92.8 154 227 *Worm Gear or Electric actuator operated Special Tests & Inspections In addition to regular hydraulic testing and air testing, Dervos could also do specials test as per clients’ requests, such as PT test, RT test, UT test, cryogenic test, low leakage test, fire proof test, and hardness test and so on.
Chinese manufacturer Dervos offers 14 Inch swing check valves made according to API 6D. Other features cover CL300, RF End Connection, WCB body.
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.
With butt weld end and gearbox, the fully welded ball valve is designed per ASME B16.34. The one piece ball valve has trunnion type ball, antistatic design and full port structure. Quick Detail Type Ball Valve Size 10" Pressure ANSI 300 Construction Trunnion Type, One Piece Body, Full Bore, Fully Welded Connection Butt Weld (BW) Operation Gearbox Body Material Forged Steel A105 Design API 6D Pressure & Temp ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.25 Inspection API 598 Temperature Range -29℃~+125℃ Media W.O.G Related Knowledge What is a fully welded ball valve? What is the benefit and advantage of a fully welded ball valve? A fully welded ball valve is welded after forging without any bolted connection on the body. Compared with flanged ball valve, it features in maximum strength at minimum weight. The design of the valve gives it advantage: -Overall small size and light weight -Fewer leak paths on the body -High machining precision of ball part -High resistance to external and internal pressure and strength 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.
12" 300LB gate valve is made according to API600 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of bolt cover, rising stem, elastic gate and full flow. Its connection mode is RF. And it has gearbox operation mode.
The 1 inch sleeved type plug valve is made of A216 WCB as per API 599. Thanks to its PTFE seat, the valve has excellent sealing and anti-corrosion performance. The valve is capable in working condition lower than 180 degree.
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