Clamping check valve is also known as reverse flow valve, reverse check valve, back pressure valve, one-way valve. These valves are automatically opened and closed by the flow of the medium itself in the pipe.

Technical parameters

Nominal pressure or pressure level: pn1.00-16.0 MPa, ANSI CLASS 150-900, jis10-20k
Nominal size or bore: DN15 ~ 900, NPS 1/4 ~ 36
Connection: flange, butt welding, thread, socket welding, etc
Applicable temperature: 196 ℃ ~ 540 ℃
Body material: WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8(304), CF3(304L), CF8M(316), CF3M(316L), Ti.
Different materials can be used for water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea and other media.

Job characteristics

The operating characteristic of check valve is that the load changes greatly, the frequency of opening and closing is small. But when there is a "switch" requirement, it must be flexible, which is more demanding than the usual mechanical movement.

Due to the check valve in the most practical use, qualitatively determine for fast shut down, and at the instant of the check valve is closed, the medium is a direction, with the disc in closing, the medium from the rapid rate of maximum back down to zero, while the pressure rise rapidly, generating possible damage to pipeline system of "water hammer" phenomenon.

For high pressure pipeline systems with multiple pumps in parallel, the water hammer problem of check valve is more prominent. Water hammer is a kind of pressure wave in the transient flow in the pressure pipeline. The physical reason is the result of the combined action of incompressibility of fluid, inertia of fluid motion and elasticity of pipeline. In order to prevent the water hammer hidden trouble in pipeline, some new structures and new materials have been adopted in the design of check valve for many years, which has made great progress in ensuring the application performance of check valve and minimizing the impact force of water hammer.

Use

The check valve is used in the pipeline system. Its main function is to prevent backflow of medium, reverse of pump and its driving motor, and discharge of medium in the container. The check valve can also be used to provide a supply line to the auxiliary system where pressure may rise above the main system pressure. Check valve can be applied to all kinds of medium pipe according to different materials. When the check valve is installed on the pipeline, it becomes one of the fluid components of the complete pipeline. In turn, the closing characteristic of the disc affects the flow state of the fluid.