In a wedge gate valve, the gate sealing surfaces are wedge-shaped, forming a specific angle relative to the gate centerline. The gate is driven downward by the valve stem to achieve closure. As the stem thrust increases, the normal force acting on the wedge-shaped sealing surfaces also increases, creating a forced sealing effect. This design significantly improves sealing performance under low-pressure conditions. During opening, the gate sealing surfaces disengage from the seat immediately, which helps reduce wear on the sealing faces and extends the service life of the valve. Applicable Standards for Wedge Gate Valves Wedge gate valves are commonly manufactured in accordance with the following standards: ● GB/T 12234-2019 – Steel gate valves with bolted bonnet for petroleum and natural gas industries ● GB/T 12232-2005 – General-purpose flanged cast iron gate valves ● API Standard 600 (2015) – Steel gate valves for petroleum and natural gas industries Types of Wedge Gate Valve Gates Wedge gate valves are typically available in three gate configurations:Solid wedge gate, Flexible wedge gate, Double wedge gate. The flexible wedge gate and double wedge gate rely on controlled deformation of the sealing surfaces to achieve improved contact with the valve seat. This design enhances sealing reliability and effectively prevents gate binding or jamming caused by temperature variations, ensuring smooth operation even under fluctuating thermal conditions. Parallel Slide Gate Valve Design and Sealing Principle In a parallel slide gate valve, the sealing surfaces at both the inlet and outlet ends of the gate are parallel to the gate centerline. For single-gate configurations, sealing is primarily achieved by the medium pushing a floating gate or floating seat into position. In double-gate configurations, sealing can be accomplished through springs or an expansion mechanism between the gates. Throughout the opening and closing process, the gate and seat sealing surfaces remain in constant contact, ensuring reliable sealing. Applicable Standards for Parallel Slide Gate Valves Common standards for parallel slide gate valves include: ● GB/T 23300-2009 – Parallel slide gate valves ● JB/T 5298-2016 – Steel parallel slide gate valves for pipelines ● API 6D – Pipeline valves for petroleum and natural gas industries Types and Features of Parallel Slide Gate Valves Parallel slide gate valves are available in single-gate and double-gate configurations. ● Gates may include flow-through holes or be solid. Gates with flow-through holes match the seat inner diameter, facilitating cleaning and drainage of the pipeline. ● Sealing can be configured at the inlet end, outlet end, or at both ends, depending on application requirements. This design ensures flexibility in sealing arrangements while maintaining reliable oper...
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!
Payment:
30% when order confirmed, 70% before shipmentProduct Origin:
chinaColor:
CustomizationShipping Port:
Shanghai, ChinaLead Time:
30~60 days Ex Works after order confirmationMaterial:
ASTM A494 CU5MCuCMethod of Operation:
Gear Operator6" 600LB CU5MCuC Casting Trunnion Ball Valve is made according to API 6D standard. The valve body is made of ASTM A494 CU5MCuC. It has the structural characteristics of Trunnion Mounted Ball (DBB), with Stem and Seat Grease Injection, Fire-safe Design to API 6FA, Anti-static and Blow-out Proof Design, Materials Comply with NACE MR0175. Its connection mode is RTJ. And it has Gear Operator (with Locking Device) operation mode.
|
Type |
Casting Trunnion Ball Valve |
|
Size |
6” |
|
Pressure |
600LB |
|
Connection |
RTJ |
|
Operation |
Gear Operator (with Locking Device) |
|
Body Material |
ASTM A494 CU5MCuC |
|
Design Norm |
API 6D |
|
Face to Face |
ASME B16.10 |
|
End connection |
PTJ |
|
Test & Inspection Code |
API 598 |
|
Temperature |
-35 ~ 160°C |
|
Applicable Medium |
Water, Oil and Gas |
1.CU5MCuC cast nickel-aluminum bronze body offers excellent resistance to seawater corrosion and cavitation.
2.Trunnion-mounted ball design with RTJ ends ensures stable sealing performance and reliable operation under Class 600 pressure conditions.
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The 12 inch 600LB trunnion mounted ball valve has gearbox, RTJ flange, fire safe design per API 607. The 3 piece ball valve is designed per API 6D. Design Feature & Benefit 1.Small flow resistance means less pressure drop 2.Simple valve structure and light weight 3.Diversified sealing material available, from metal material TCC, satellite, stainless steel to soft material PTFE, Teflon, Nylon, Peek and etc 4.Good performance of both metallic sealing and soft sealing 5.Convenient and swift operation of the valve 6.Easy to maintain due to renewable seat ring 7.When fully opened or closed, the valve sealing face is isolated from medium corrosion. 8.Wide range of application in terms of size and pressure rating Quick Detail Type Ball Valve Size 12" Pressure Class 600 Construction Trunnion Mounted Ball, Three-Piece Type, Side Entry Connection RF Flange Operation Gear Operated Body Material ASTM A105 Design & Manufacture API 6D Pressure & Temp ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.5 Test & Inspection Code API 598 Fire Safe API 607 Temperature Range -29℃~+200℃ Medium Water, Oil and Gas Origin China Material Specification No Part Name Carbon steel to ASTM Stainless Steel to ASTM WCB LCB CF8 CF8M CF3 CF3M 1 Underplate WCB LCB CF8 CF8M CF3 CF3M 2 Underplate Bolt A193 B7 A320 L7 A193 B8 3 Trunnion A182 F6 A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 4 Body A216 WCB A352 LCB A351 CF8 A351 CF8M A351 CF3 A351 CF3M 5 Bonnet Nut A194 2H A194 4 A194 8 6 Bonnet Bolt A193 B7 A320 L7 A193 B8 7 Cap A216 WCB A352 LCB A351 CF8 A351 CF8M A351 CF3 A351 CF3M 8 Gasket SS Spiral Wound/graphite or SS Spiral Wound/PTFE 9 Shaft Sleeve SS/graphite 10 Seat Ring RPTFE or POM 11 Ball A105/Ep.Cr or F6 A182 F6 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 12 Seat A105/Ep.Cr or F6 A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 13 Spring 17-17PH(inconel for NACE)Ni-cr Alloy 14 O-Ring Viton 15 Stem A182 F6 A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 16 Sealing Cover A182 F6 A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 17 O-Ring Viton 18 Gear Actuator The material is according to ASTM standard Related Knowledge What is difference between floating and trunnion ball valve? The ball part of floating ball valve is movable. Under the pressure of medium, the ball has a certain displacement and presses on the sealing surface of outlet end to ensure its tight sealing. The floating structure is suitable for ball valve with small size and low & medium pressure rating. The ball part of trunnion mounted ball valve is fixed. Under the medium pressure, the floating seat will move towards the ball to ensure the sealing. The trunnion mounted ball valve is often with larger size and higher pressure.
The Class 300 flanged ball valve has cast steel WCB body, stainless steel ball, stem, seat ring along with Devlon seat insert. We also supply more types of trunnion mounted ball valve, accept customized. Design Feature 1.Firesafe design as per API 607 2.With sealant injection for self lubricating 3.With antistatic design 4.With anti-blowout stem 5.With vent and drain port 6.Full bore design 7.Three-piece type and trunnion ball 8.Gear operated for easy operation Quick Detail Type Ball Valve Size 24" Pressure ANSI 300 Construction Trunnion Type Ball, 3-Piece Body, Side Entry, Full Bore Connection Flange Connection Operation Gearbox Operation Body Material ASTM A216 WCB Design Code API 6D Pressure & Temp Code ASME B16.34 Face to Face ASME B16.10 End Connection ASME B16.5 Test & Inspection Code API 598, API 6D Fire Safe API 607 Temperature Range -29℃~+200℃ Medium WOG Origin China Dimension CLASS 300 DN mm 50 65 80 100 150 200 250 300 350 400 450 500 600 700 NPS in 2 2.5 3 4 6 8 10 12 14 16 18 20 24 28 L (RF) mm 216 241 283 305 403 502 568 648 762 838 914 991 1143 1346 in 8.5 9.5 11.13 12 15.88 19.75 22.38 25.5 30 33 36 39 45 53 L1 (BW) mm 216 241 283 305 457 521 559 635 762 838 914 991 1143 1346 in 8.5 9.5 11.13 12 18 20.5 22 25 30 33 36 39 45 53 L2 (RTJ) mm 232 257 298 321 419 518 584 664 778 854 930 1010 1165 1372 in 9.13 10.13 11.75 12.63 16.5 20.38 23 26.13 30.63 33.63 36.63 39.75 45.89 54 H mm 153 165 195 213 272 342 495 580 625 720 790 840 1050 1150 in 6.02 6.5 7.68 8.39 10.7 13.5 19.5 22.85 24.6 28.35 31 33.1 41.34 45.3 Do(W) mm 400 400 600 850 1100 1500 *350 *350 *600 *600 *800 *800 *800 *800 in 15.74 15.74 23.62 33.46 43.3 59 13.8 13.8 23.6 23.6 31.5 31.5 31.5 31.5 RF(Kg) 18 27 47 80 118 200 365 530 740 1030 1320 1540 2600 3900 BW(Kg) 14 2 38 65 105 185 342 503 713 1000 1285 1498 2540 3825 *Worm Gear or Electric Actuator Operated Dervos Quality Checking System In Dervos, we control quality throughout the whole manufacturing process. Casting inspection: Though casting inspection, we can find out the problem of raw material, such as shoddy casting, unqualified wall thickness, chemical composition and so on, which ensure that you will not be cheated. Machining Inspection: On the one hand, we could ensure machining accuracy through this process. On the other hand, we can find out machining mistake as early as possible, to win more time for repairing and remaking Final Inspection: Final inspection activities include document and QC record review, visual examination, dimension check, pressure test, painting and packing check. You don’t need to come and inspect in person and all the documents could be provided as proof.
Trunnion mounted ball valve DN300 PN63 full bore Double Block and Bleed PMSS seal(metal seal+soft seal）blowout proof stem gearbox operation with LF2 body, LF2+ENP ball/seat and 410 stem. Quick Detail Type Ball Valve Size DN300 Design Pressure PN63 Construction DBB,Trunnion mounted ball valve ConnectionType Flange OperationType Gearbox Operated Body Material LF2 Ball Material LF2+ENP Stem Material 410 Seat Material LF2 +ENP Design Code API 6D Face to Face Dimension API 6D End Connection ASME B16.5 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China
API 6D ball valve is designed with trunnion mounted ball and full bore structure. The flanged ball valve has 300LB design pressure and 8 inch nominal size with gearbox operation mode, conforming to NACE MR0175 requirement. Quick Detail Type Ball Valve Size 8” Pressure 300LB Construction Two-Piece Body, Full Bore, Trunnion Ball Connection RF Flange Operation Mode Gearbox Body Material A216 WCB Trim Material Ball/Stem F6a, Seat RPTFE Design & Manufacture API 6D Pressure & Temp Code ASME B16.34 End to End ASME B16.10 End Connection ASME B16.5 Inspection API 6D, API 598 Temperature Range -29℃~+200℃ Medium Oil, Water, Gas Dervos Packing Painting Test & Report Pressure Testing & Dimension Checking
The API 6D ball valve is designed with trunnion mounted ball and full bore structure. The flanged ball valve has 600LB design pressure and 10 inch nominal size with gearbox operation mode, conforming to NACE MR0175 requirement.
The 4 inch 150LB ball valve is a 3-piece one with reduced port, A105 body, F6A stem, ball and seat. The The valve is made as per API6D and is tested under API 598.
The 150LB ball valve, made of Duplex stainless steel 4A, has a special V port ball. The valve is particularly suitable for media containing fibers, tiny solid particles, slurry and so on.
China Carbon Steel Ball Valve Provider Offers 3 Piece Position Type Ball Valve, ASTM A105N, Class 800, 1 Inch, Free Floating Ball, API 608, BS 5351.
DN150 PN16 Ball Valve is made according to ISO 17292 standard. The fire resistance test meets the requirements of API 607 standard. The valve body is made of ASTM A105. Its operation mode is turbine operation. The trunnion mounted ball valve with a structural length of 400mm has the structural characteristics of full bore.
8" 2500LB ball valve is made according to API 6D standard. The valve body is made of F51. It has the structural characteristics of trunnion mounted ball, full bore. It also has the design of anti-fire, anti-static and anti-flying valve stem. In addition, it also meets NACE MR0175 requirements.
2" 1500LB ball valve is made according to API 6D standard. It also complies with the design standard of NACE MR0175. The valve body is made of ASTM-A105. It has the structural characteristics of full flow and trunnion mounted ball. It has RTJ connection mode and gearbox operation mode.
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