Damage to valve sealing surfaces is typically the result of multiple contributing factors, including material selection, operating conditions, operating practices, and maintenance. The following is a categorized summary of the most common causes: 1. Mechanical Damage ● Wear: Solid particles in the medium (such as sand or welding slag) erode the sealing surface, resulting in scratches or grooves. ● Abrasive scuffing: Frictional wear caused by relative movement of the sealing surfaces during valve opening and closing, particularly in metal-to-metal sealing pairs. ● Impact damage: Deformation of the sealing surface caused by high-velocity fluid impingement or rapid valve opening and closing, leading to impact loading. 2. Chemical Corrosion ● Media corrosion: Acidic, alkaline, or oxidizing media directly attack the sealing surface material, such as metal corrosion caused by H₂S or chloride ions. ● Electrochemical corrosion: When sealing pairs made of dissimilar metals are exposed to an electrolyte, galvanic corrosion may occur due to electrochemical cell formation. ● Erosion–corrosion: The combined effect of corrosive media and high-velocity flow accelerates material loss on the sealing surface. 3. Thermal Damage ●Thermal fatigue:Frequent temperature fluctuations cause repeated thermal expansion and contraction of the sealing surface, leading to cracking or deformation. ●High-temperature oxidation:At elevated temperatures, the sealing surface may undergo oxidation, hardening, or burn-off, as commonly observed in steam valve applications. ●Thermal shock:Sudden exposure to high- or low-temperature media can cause cracking of the sealing surface, such as during rapid condensation or cold media ingress. 4. Improper Installation and Operation ●Installation misalignment: Incorrect valve installation or excessive piping stress can result in uneven loading on the sealing surfaces. ●Over-tightening: Excessive preload applied to the valve stem or bolting may crush or deform the sealing surface, particularly in soft-seated valves or soft sealing gaskets. ●Rough operation: Rapid opening and closing or excessive operating force can cause impact damage to the sealing surfaces. 5. Material Defects ●Improper material selection: The sealing surface material lacks sufficient resistance to process media, high temperature, or wear, such as the use of carbon steel in acidic service. ●Manufacturing defects: Defects in the hardfacing or overlay layer, including porosity, slag inclusions, or improper heat treatment, reduce wear resistance and overall sealing performance. 6. Abnormal Operating Conditions ●Cavitation / flashing: Pressure fluctuations in the fluid generate vapor bubbles that collapse and impact the sealing surface, a phenomenon commonly observed in valves installed downstream of pumps. ●Scaling / deposition: Impurities in the medium accumulate on the sealing surface, impairing tight shutoff, suc...
In 2025, Dervos organized its annual team trip, a five-day journey to Chongzuo, Weizhou Island, and Nanning in Guangxi Province. The trip aimed to provide relaxation and strengthen team communication, offering a well-paced and content-rich experience that combined natural landscapes with local cultural immersion. In Chongzuo, the team focused on nature sightseeing. Bamboo rafting tours allowed close observation of the local ecology and offered opportunities to see rare species such as the white-headed leaf monkey. The group also visited Detian Waterfall, experiencing its scale and flow firsthand. The overall itinerary was designed with a relaxed pace, providing ample time for rest and team bonding. Next, the team traveled to Weizhou Island. The volcanic landforms and coastal scenery added a unique visual dimension to the journey. Beyond sightseeing, participants engaged in local agricultural activities, including dragon fruit picking and banana harvesting, gaining insight into local lifestyles. The team also visited several beaches, fully appreciating the island environment. The final stop was Nanning. Team members explored the night market, sampled local specialties, and experienced the city’s daily life, bringing the Guangxi trip to a relaxed conclusion. This annual trip allowed the Dervos team to foster more natural communication and connection outside of work, recharging energy for the months ahead. Dervos remains committed to its guiding principle: I come, I see, I conquer!
These symptoms typically indicate a mismatch in fluid conditions, valve selection, or system configuration. If left unaddressed over prolonged operation, they can accelerate valve wear and pose safety risks. Based on field experience, this article outlines the common causes of valve vibration and noise and provides practical guidance for troubleshooting. 1. Basic Manifestations of Valve Vibration and Noise Valve vibration usually appears as noticeable oscillations of the valve body, stem, or connected piping. Noise may present as humming, whistling, or banging sounds. These phenomena often occur simultaneously and are primarily related to the following factors: ● Abnormal flow velocity or pressure differential ● Unstable internal forces within the valve ● Mismatch between actual operating conditions and valve design 2. Common Causes Analysis 1. Excessive Flow Velocity or Pressure Differential When the fluid passes through the throttling section of a valve at high speed, strong turbulence and pressure fluctuations are likely to occur, causing periodic impact on internal components. This issue is particularly pronounced when using standard globe valves or ball valves under regulating conditions. Typical manifestations include: ● Noise increases as the valve opening decreases ● Vibration intensifies under high-pressure-drop conditions 2. Improper Valve Selection Incorrect valve selection is a common root cause of vibration, such as: ● Using on/off valves for prolonged throttling ● Oversized valve operating at small openings for extended periods ● Insufficient pressure rating or structural rigidity of the valve These conditions can cause unstable movement of the valve plug or ball, resulting in vibration and noise. 3. Loose or Worn Internal Components After long-term operation, the following issues are commonly observed: ● Wear of valve plugs or discs ● Increased clearance between the stem and guiding parts ● Loosened fasteners Non-design clearances amplify fluid impact, leading to persistent noise. If vibration is accompanied by metallic knocking sounds, the condition of internal components should be checked as a priority. 4. Cavitation or Flashing In liquid service, cavitation or flashing occurs when local pressure drops below the saturation vapor pressure. Bubble collapse in high-pressure regions impacts internal components, often accompanied by noise and vibration. Typical signs include: ● Sand- or gravel-like scraping sounds ● Rapid wear of internal components ● Significant pressure fluctuations 5. Insufficient Piping Support or System Resonance Some vibrations are not directly caused by the valve. When upstream or downstream piping lacks adequate support, or when the piping structure resonates near the fluid pulsation frequency, system resonance may occur, amplifying existing vibrations...
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.
DN100 PN40 Stainless Steel Gate Valve is made according to EN 1984 standard. The valve body is made of X6CrNiMoTi17-12-2. EN 1.4571 (AISI 316Ti) is widely used in medium- to high-temperature applications where resistance to intergranular corrosion and moderate chloride corrosion is required, especially in welded systems without post-weld heat treatment. Its connection mode is EN558. And it has Hand Wheel operation mode. Product Parameters Type Stainless Steel Gate Valve Size DN100 Pressure PN40 Connection EN 558 Operation Hand Wheel Body Material X6CrNiMoTi17-12-2 Design Norm EN 1984 Face to Face dimension EN 1092 End connection EN 558 Test & Inspection Code EN 12266-1,2 Temperature -29 ~ 425°C Applicable Medium Water, Oil and Gas Features 1.Made from EN 1.4571 stainless steel, offering excellent corrosion resistance and high-temperature stability for PN40 pressure applications. 2.Gate valve design compliant with EN 1984 ensures reliable shutoff and long service life in industrial piping systems. Technical Drawing Dimension Checking Pressure Testing Spectrum Nameplate & Packing
DN150 PN40 Stainless Steel Gate Valve is made according to EN 1984 standard. The valve body is made of X6CrNiMoTi17-12-2. EN 1.4571 (AISI 316Ti) is widely used in medium- to high-temperature applications where resistance to intergranular corrosion and moderate chloride corrosion is required, especially in welded systems without post-weld heat treatment. Its connection mode is EN558. And it has Hand Wheel operation mode. Product Parameters Type Stainless Steel Gate Valve Size DN150 Pressure PN40 Connection EN 558 Operation Hand Wheel Body Material X6CrNiMoTi17-12-2 Design Norm EN 1984 Face to Face dimension EN 1092 End connection EN 558 Test & Inspection Code EN 12266-1,2 Temperature -29 ~ 425°C Applicable Medium Water, Oil and Gas Features 1.EN 1.4571 stainless steel construction provides strong resistance to pitting and stress corrosion in aggressive media. 2.DN150 PN40 configuration designed to EN 1984 standard ensures stable operation and tight isolation in medium-pressure pipelines. Technical Drawing Dimension Checking Pressure Testing Spectrum Nameplate & Packing
2" 150LB Y Strainer is made according to ASME B16.34 standard. The valve body is made of LCB. It has the structural characteristics of Y-Type, Double Mesh Screen, Mesh Size 1/16", Hole Pitch 3/32". Its connection mode is RF.
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.
The 20 inch metal seated ball valve is designed for high temperature application or application with solid particulate. The valve has welded body, RF flange connection, bare stem for actuators, belonging to trunnion mounted type. Quick Detail Type Ball Valve Size 20" Pressure ANSI 600 Construction Trunnion Type, One-Piece Body, Fully Welded, Metal to Metal Seat Connection Flanged Operation Bare Stem Body Material Forged Steel ASTM A105 Design Standard API 6D Pressure & Temp ASME B16.34 Face to Face Dimension ASME B16.10 End Connection ASME B16.5 Inspection API 598 Temperature Range -29℃~+200℃ Media Oil, Water, Gas Dimension CLASS 600 DN mm 50 65 80 100 150 200 250 300 350 400 450 500 NPS in 2 2.5 3 4 6 8 10 12 14 16 18 20 L (RF) mm 292 330 356 432 559 660 787 838 889 991 1092 1194 in 11.5 13 14 17 22 26 31 33 35 39 43 47 L1 (BW) mm 292 330 358 432 22 660 787 838 889 991 1092 1194 in 11.5 13 14 17 559 26 31 33 35 39 43 47 L2 (RTJ) mm 295 333 359 435 562 664 791 841 892 994 1095 1200 in 11.63 13.13 14.13 17.13 22.13 26.13 31.13 33.13 35 39.5 43.1 47.3 H mm 153 165 195 213 272 342 495 580 630 725 800 850 in 6.02 6.5 7.68 8.39 10.7 13.5 19.5 22.85 24.8 28.5 31.5 33.5 Do(W) mm 600 850 1250 1300 1500 *350 *350 *600 *600 *800 *800 *800 in 23.62 33.46 49.25 51.22 59 13.8 13.8 23.6 23.6 31.5 31.5 31.5 RF(Kg) 38 56 66 122 217 350 660 820 830 1160 1420 1650 BW(Kg) 31 51 58 117 200 327 605 790 800 1030 1305 1505 *Worm Gear or Electric actuator operated Related Knowledge When to use metal seated ball valve? The seat of a metal seated ball valve is often stellite, stainless steel, or tungsten carbide instead of soft seat material like ptfe, peek, nylon, teflon, and devlon. These metal to metal seat ball valves are especially applicable for: -Media with high temperature -Media with solid particulate for high abrasion -Media with severe condition, like high erosion and corrosion -Media with high viscosity like heavy oil Our Main Product Range Dervos main products include ball valves, butterfly valves, check valves, gate valves, globe valves, and plug valves in different materials, sizes, standards and types as per clients’ requests.
The 8 inch 150 LB dual disc non return check valve, designed per API 594, has dual plate and lug connection. The retainerless dual plate check valve is made of duplex stainless steel 4A as its body and trim material. Quick Detail Type Check Valve Size 8'' DesignPressure Class 150 Construction Dual Plate Type, Retainerless Connection Lug Type Design & Manufacture API 594 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material Duplex Stainless Steel 4A Trim Material Duplex Stainless Steel Media W.O.G. Design Feature 1.Shor face to face dimension 2.Small in size with light weight 3.Swift close of disc with small water hammer 4.Vertically or horizontally installed 5.Smooth flow passway with small flow resistance 6.Long cycle life and high reliability
4" 150LB Double Eccentric Butterfly valve is made according to API609 standard. The valve body is made of WCB. It has the structural characteristics of high performance, dual eccentricity, butterfly plate with bolt holes, bi-directional sealing. Its connection mode is wafer.
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