Size: | DN50-DN900 |
Pressure: | PN16-PN250 |
Body Material: | WCB, WC6, WC9, CF8, CF8M, CF3, CF3M, CN7M, LC1, LC2, LC3, LCB, LCC, Monel, 20# Alloys, 4A, 5A, C95800, C95500, A105, F304, F304L, F316, F316L, LF1, LF2, LF3, LF9, F51, F53, F11, F22, etc. |
Seal Material: | STELLITE, 13Cr, SS304, SS316, etc. |
Connection Type: | Flanged, Butt Welded, Socket Welded, NPT |
Face to Face Dimension: | EN558-1/DIN3202 F1 |
Flange End Dimension: | EN1092-1/DIN2545 |
Design and Manufacture: | EN 13709/DIN3356 |
Test Standard: | EN14341/DIN3840 |
Bolted bonnet & welded bonnet & pressure seal bonnet & union bonnet
Swing type & Piston type & Dual plate type & Tilting type
The wafer check valve is divided into hard seal and soft seal.
Suitable for petroleum, chemical, pharmaceutical, chemical fertilizer, power industry, low temperature, and other conditions of the pipeline
Sealing surface seated with stellite, wear resistance, corrosion resistance, good anti-friction performance, long service life
The basic working principle of a check valve is quite simple. It consists of a valve body with an inlet and an outlet, and a movable valve element, often referred to as a disc or a flap. The valve element is designed in such a way that it can move freely within the valve body. api 6d ball valve
Here's how a check valve works:
Flow Direction: Check valves are designed to allow fluid to flow in one specific direction. The inlet is where the fluid enters, and the outlet is where it exits. The check valve is installed in a way that ensures the fluid flows from the inlet to the outlet.
Valve Element: Inside the valve body, there is a valve element (typically a flat or conical disc) that is mounted on a hinge or pivot point. This valve element can move freely within the valve body.
Opening and Closing: When fluid flows in the desired direction (from the inlet to the outlet), the pressure of the fluid pushes against the valve element, causing it to open, allowing the fluid to pass through the valve unimpeded. forged ball valve
Preventing Backflow: If there is a reverse flow, meaning fluid tries to move from the outlet to the inlet, the valve element is forced by the pressure difference to close. The valve element seals off the passage and prevents backflow.
Check valves are designed to work passively, relying on the force of the fluid itself to open and close the valve. They do not require any external power source or control system. Check valves are essential in applications where it is crucial to prevent the reverse flow of fluids, such as in preventing backflow in plumbing systems or maintaining the direction of flow in certain industrial processes. carbon steel gate valves
Check valves do not typically reduce flow when they are operating in the intended direction. In the direction in which the check valve is designed to allow flow (from the inlet to the outlet), the valve remains open, and the fluid can pass through with minimal resistance. This is because the check valve is designed to open fully in response to the pressure of the flowing fluid. high temperature gate valves
However, it's important to note that while check valves are intended to allow flow in one direction and prevent it in the reverse direction, they can introduce some minor resistance or pressure drop to the system, particularly when the valve element is in the closed position. This resistance is generally minimal in most applications and is often a necessary trade-off to prevent backflow and maintain system integrity.
The level of resistance or pressure drop introduced by a check valve can vary depending on several factors, including the type and design of the check valve, the size of the valve, the type of fluid, and the flow rate. For example, swing check valves and ball check valves may introduce slightly more resistance compared to other types of check valves due to the design of their valve elements.
In situations where minimizing pressure drop is critical, careful selection of the appropriate type and size of check valve can help to mitigate any potential flow reduction. Additionally, regular maintenance and cleaning of check valves can ensure that they continue to function efficiently and do not cause unnecessary flow restrictions, low temperature ball valves.
The DIN (Deutsches Institut für Normung or German Institute for Standardization) standards are commonly followed for a wide range of industrial components, including check valves. DIN standards include specifications for pressure testing check valves to ensure their performance and reliability. For DIN check valves, the relevant standards for pressure testing are typically DIN EN 12266-1 and DIN EN 12266-2. These standards provide guidance on the testing procedures and acceptance criteria for different types of industrial valves, including check valves, api602 forged gate valve.
A Screw Down Non-Return Valve (SDNR valve), also known as a non-return globe valve, is a type of valve designed to allow fluid to flow in one direction while preventing backflow in the opposite direction. It is similar in function to a conventional globe valve but with a specific design intended for applications where backflow prevention is essential. Here's how an SDNR valve works:
Valve Design: An SDNR valve consists of a valve body with an inlet and an outlet, a valve seat, a disc, and a stem with a handwheel or actuator. The key feature of an SDNR valve is that it includes a non-return or check valve mechanism in the design.
Flow Direction: SDNR valves are designed to allow fluid to flow from the inlet to the outlet. The flow direction is typically indicated on the valve body.
Valve Operation:
Globe Valve Function: When the handwheel or actuator is turned in the open position, the valve functions like a globe valve. In this position, the disc is lifted away from the valve seat, allowing fluid to flow through the valve in the intended direction.
Check Valve Function: The SDNR valve also incorporates a check valve mechanism. When the fluid flow direction tries to reverse (i.e., fluid flows from the outlet to the inlet), the check valve mechanism prevents this backflow. The disc moves to the closed position under the influence of the check valve, blocking the reverse flow.
The key component that enables the check valve function is the disc, which has a design that provides a tight seal against the valve seat to prevent backflow. When the valve is closed, the disc is pressed firmly against the valve seat, ensuring a secure seal.
Wafer-type check valves come in two main variations known as "long pattern" and "short pattern." These terms refer to the design and dimensions of the valve body and have implications for the installation and use of the valve in different applications. Here's an explanation of each:
Long Pattern Wafer Check Valve:
Design: Long pattern wafer check valves have an elongated, extended body design. The length of the valve body is typically longer than that of a short pattern wafer check valve.
Application: Long pattern wafer check valves are often used in applications where there is ample space for installation, and they can accommodate a longer face-to-face dimension. They are suitable for systems that require higher flow capacity or where reduced pressure drop is desired.
Short Pattern Wafer Check Valve:
Design: Short pattern wafer check valves have a more compact, shorter valve body design. The length of the valve body is shorter compared to the long pattern version.
Application: Short pattern wafer check valves are used in applications where space is limited or when a shorter face-to-face dimension is acceptable. They are often more cost-effective and may be used in systems where lower flow rates and pressure drop are acceptable.
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