Ball valves and plug valves differ significantly in several aspects, including structure, operating principle, mode of operation, flow control capability, sealing performance, and application scenarios. These differences enable the two types of valves to perform distinct roles in their respective fields. Structural Differences The ball valve, a design evolved from the plug valve, utilizes a spherical element as its core component. By rotating the ball 90° around the stem axis, the valve can be opened or closed. Its structure is straightforward, consisting primarily of a spherical closure element with a through-bore housed within the valve body. In contrast, the structure of a plug valve is more complex. It comprises multiple components such as the valve body, bonnet, plug, seat, and stem. The closure element is a cylindrical or tapered plug that controls flow by rotating 90°, aligning or misaligning the port in the plug with the flow passage in the valve body to achieve opening or shutoff. Operating Principle The operating principle of a ball valve relies on the rotation of the ball to control the on-off flow of fluid. When the ball is in tight contact with the valve seat, the clearance between them is completely sealed, thereby preventing fluid leakage. When the ball rotates to a position disengaged from the seat, the fluid is allowed to flow freely through the passage inside the valve body. The operating principle of a plug valve differs in that it primarily controls the flow passage by rotating the plug element to open or close the valve. In a plug valve, the plug is connected to the stem and rotates together with it to achieve flow control. The closure element is a tapered plug with a port, and the flow passage is designed to be perpendicular to the axis of the plug. This configuration enables the plug valve to operate more efficiently and reliably during opening and closing. The operation of a ball valve is notably simple, requiring only a 90-degree rotation to achieve opening or closing. This design allows the flow passage to be opened or shut off quickly and smoothly when the ball is rotated by 90 degrees, providing both convenience and efficiency. In addition, ball valves offer relatively low flow resistance in the fully open or fully closed position, making them particularly suitable for applications that require rapid on-off operation. By contrast, the operation of a plug valve is comparatively more complex, as several turns are typically required to complete the opening or closing action. The valve plug is designed in a cylindrical or tapered form and regulates fluid flow through rotation. Nevertheless, plug valves demonstrate excellent performance in flow regulation, enabling precise adjustment of the flow passage diameter and accurate control of flow rate. However, due to the relatively complicated operating process, plug valves are not well suited for frequent operation...
In industrial valve systems, a high-quality blind plate valve ensures safe and efficient operation of equipment. It is suitable for gas pipelines in metallurgy, chemical processing, petroleum, and municipal systems, serving as an effective device for positive gas isolation. Working Principle and Features The blind plate valve consists of left, center, and right valve bodies, a valve plate, shafts, a compensator, and two drive units (for clamping and travel respectively). The clamping mechanism uses a drive assembly to actuate a linkage system, enabling three lead screws to operate synchronously and press the valve bodies against the valve plate to achieve sealing. This design provides good synchronization and uniform sealing force distribution. Positioning rollers are installed along the outer lower edge of the valve plate to enhance sealing reliability and ensure overall stability and sealing accuracy during operation, thereby extending the service life of the valve. Valve Operating Sequence The clamping drive unit actuates the crank and linkage mechanism, causing the lead screws to rotate synchronously and retract the center body from the sealing surfaces (release condition). Guide wheels installed on the center body move laterally and simultaneously drive the valve plate. When the valve bodies are fully opened, the valve plate is positioned between the sealing faces of the left and right bodies, and the sealing surfaces are completely disengaged. The plate drive unit is then activated. Through a lever arm mechanism, the valve plate rotates, bringing the blind plate into the pipeline position. The clamping drive unit is started again to fully clamp the valve plate, completing valve closure. Valve Opening The clamping drive unit first fully releases the valve bodies. The turning drive unit then rotates the valve plate so that the through-port aligns with the pipeline. Finally, the clamping electric actuator presses the valve plate to complete the opening operation.
Wide-body ball valves and single-piece ball valves are both types of ball valves used for controlling the on/off flow of medium in pipelines. Both wide-body and single-piece ball valves feature a one-piece (integral) body design, unlike split-body designs. This differs from two-piece and three-piece ball valves, which have segmented valve bodies. For internally threaded wide-body ball valves, the valve body is made from round or hexagonal stock, using either bar material or forged components. The ball core features a reduced-diameter design and is inserted from one side of the valve body. The stem uses an internal anti-blowout structure. Flat surfaces are machined on both the inlet and outlet sides of the body to facilitate assembly of the ball valve and allow the use of wrenches during pipeline installation. In wide-body ball valves, the stem stuffing box is relatively shallow, and the internal packing volume is limited, resulting in a moderate sealing performance of the stem. Therefore, these valves are more suitable for low-pressure medium applications. In contrast, two-piece and three-piece ball valves feature stem stuffing box structures that provide reliable sealing for high-pressure medium applications. The structure of flanged wide-body ball valves is essentially the same as that of internally threaded wide-body ball valves. Typically, the flange is connected to the intermediate valve body via threaded fasteners, although some designs utilize a forged one-piece structure. Externally threaded wide-body ball valves can use a union-type structure, where the union is directly welded to the pipeline and connects to the external threads on the valve body. This design allows for easy disassembly and reassembly during valve maintenance or replacement without requiring separate unions on the pipeline. The valve bodies of single-piece internally threaded ball valves and single-piece flanged ball valves are manufactured using casting processes, with the ball core featuring a reduced-diameter design. The stem uses an internal anti-blowout structure. The inlet and outlet ends of single-piece internally threaded ball valves have a hexagonal shape, similar to conventional internally threaded valves, to facilitate wrench operation and secure installation. In single-piece flanged ball valves, the flange and valve body are cast as a single unit, eliminating the need to machine and assemble the flange separately as in wide-body flanged ball valves. This approach reduces cost and simplifies the manufacturing process. Single-piece wafer-style ball valves have a shorter valve body length, making them more suitable for pipelines with limited space. Wide-body and single-piece ball valves both use a reduced-diameter ball design, resulting in higher flow resistance compared with two-piece and three-piece ball valves. The main differences are as follows: Valve Body Manufacturing Process ● Wide-bo...
The lug type knife gate valve is designed per MSS-SP-81.Made by stainless steel CF8, the 4 inch gate valve has 150 LB flange connection and handwheel operation.
Payment:
30% when order confirmed, 70% before shipmentProduct Origin:
ChinaColor:
CustomizationShipping Port:
Shanghai, ChinaLead Time:
30~60 days Ex Works after order confirmationMaterial:
CF8Product Description
|
Type |
Gate Valve |
|
Size |
4 Inch |
|
Pressure |
Class 150 |
|
Construction |
Knife Gate Valve |
|
Connection |
Lug |
|
Operation |
Handwheel |
|
Body Material |
CF8 |
|
Design Code |
MSS-SP-81 |
|
Face to Face Code |
ANSI B16.10 |
|
Pressure & Temp Code |
ANSI B16.34 |
|
Test & Inspection Code |
API 598 |
|
Temperature Range |
-196℃~+600℃ |
|
Medium |
Water, Oil and Gas |
|
Origin |
China |
Product Range
Body material: Carbon Steel, Stainless Steel, Alloy Steel, Cast Iron
Normal diameter: 2” ~ 60” (DN50 ~ DN1500)
End connection: Flange, Wafer, Lug
Operation: Handwheel, Gearbox, Electric, Pneumatic, Electro Hydraulic Actuator, Gas over oil actuator
Seat Type: Metal to Metal Seat, Soft Seat
Certificates
As a 14 years valve exporter, we have collect many different kinds of certificates to meet our customer demands. It also testifies our quality is top on valve industry.We have certificates like EAC, ISO 9001, PED CE, API607 and so on.
If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.
The 6 inch stainless steel gate valve, designed as per MSS-SP-81, has the lug type connection per Class 150 and electric actuator. Quick Detail Type Knife Gate Valve Size 6'' Design Pressure ANSI 150 Construction Knife Type Gate Valve ConnectionType Lug Type OperationType Electric Actuator Body Material ASTM A351 CF8 TrimMaterial SS304 Design Code MSS SP81 Medium Water, Oil and Gas Origin China Related Knowledge What are knife gate valves used for? Knife gate valves are originally designed for paper industry. The knife gate valve is especially applicable for heavy liquids with solid particulates, like slurry liquid, that are most corrosive, erosive and abrasive. Compared to wedge gate valve, the knife gate valve has a shorter end to end dimension and lighter weight. Plus, the knife valve has a more sharpened disc to cut through slurry and viscous medium. Both wedge gate valve and knife gate valve can only be used for on-off function not for regulating the flow. Dervos Customer Service With Dervos customer service, you will not have any concern before, during and after buying valves. Pre-sales We will reply on time and also provide technical support upon your request. Order We will check the production details with factory and customers. Sales confirmation will also be sent. During production, we will also send weekly report to let you know the order status. Before shipment, delivery note will be sent to let you know the situation. 18 Month warranty Dervos is always responsible for their products. We will provide 18 months warranty to let our customers without concern.
The stainless steel knife gate valve is designed with DN800 PN6 flange end and gearbox operation. The soft seated knife gate valve has a unidirectional sealing. Quick Detail Type Gate Valve Size DN800 Design Pressure PN6 Construction Unidirectional, Soft Seated ConnectionType Flange End OperationType Gearbox Operated Body Material CF8M DiscMaterial SS316L StemMaterial SS316 SeatMaterial PTFE Design Code MSS SP81 Medium Water, Oil and Gas Origin China Dimension Checking Pressure Tesing
The knife gate is a bi-directional lug type valve designed according to MSS-SP-81 and for industrial service applications. The design of the body and seat assures non-clogging shut off on suspended solids in industries.
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 knife gate valve is made according to MFS standard. The valve body is made of ASTM A351 CF8. It has the structural characteristics of bilateral sealing and with flow deflector. Its connection mode is lug. And it has hand wheel operation mode.
The 6 inch 150 LB single disc wafer check valve, designed per API 594, has one disc and wafer connection. It will have the best performance under -29 to 350 Celsius degree.
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.
The API 6D through conduit gate valve is designed with 600 LB flange and gearbox connection. Made of carbon steel WCB, the 20 inch gate valve has soft seat design without diversion hole.
2" 300LB Carbon Steel Y Type Strainer is made according to ASME B16.34 standard. The valve body is made of LCC. It has the structural characteristics of Y Type. Its connection mode is RF. Product Parameters Type Carbon Steel Y Type Strainer Size 2” Pressure 300LB Connection RF Body Material ASTM A352 LCC Design Norm ASME B16.34 Face to Face ASME B16.10 Flange Ends Dimensions ASME B16.5 Test & Inspection Code API 598 Temperature -46~ 350°C Applicable Medium Water, Oil and Gas Features 1.Carbon steel body designed to ASME B16.34, providing high strength and reliable performance under Class 300 pressure. 2.Y-type strainer with RF flanged ends ensures efficient particle filtration and easy installation in industrial piping systems. Technical Drawing Dimension Checking Pressure Testing Nameplate & Packing Inspection Report
The stainless steel CF8 non return valve features in non slam type disc, ANSI 150 flange end, and full port design. Quick Detail Type Non Return Valve ( Check Valve) Size 8'' DesignPressure Class 150 Construction Non Slam Type Connection RF Flange Design & Manufacture ASME B16.34 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A351 CF8 Trim Material SS304 Media W.O.G. Available Modifications for Dervos Valves -Valve Pressure -Valve Size -Reduced Bore & Full Bore -Body & Trim Material (Disc, Seat, Pin, Spring) -End Connection (Flange, BW, SW, Thread, Wafer, Lug) -Available Operation (Bare Stem, With Actuators) -Available Counterweight -Available Cylinder -Customizing Coating -Customizing Packaging Related Knowledge What is non-slam check valve? Water hammer is a hydraulic phenomenon that undergoes an abrupt change in its rate of flow and are caused by sudden shutting or slamming. Water hammer will reduce process efficiency, cause valve damage, gasket joint leaks and other problems. The non-slam check valve is designed to reduce water hammer. An internal spring can prevent the disc from slamming close.The design of a non-slam check valve could eliminate pressure flutuations, vibration and damges. Plus, the disc and spring experience minimal wear over time, which will largely extend the service lives of non-slam check compared to swing check valve.
DN125*DN80 PN25 ball valve is made according to ISO 17292 standard. The valve body is made of ASTM A105. It has the structural characteristics of fixed ball and insulation jacket. Its connection mode is EN1092-1 B. And it has gear operation mode.
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
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