Vertical check valve is a type of check valve with vertical lifting structure, and its working principle and structural design are specially optimised for vertical pipeline installation scenarios. The following analysis of its working principle, structural characteristics and installation requirements from three aspects of its working mechanism:
I. Working Principle
Forward flow stage
When the medium flows from the bottom up, the fluid pressure to overcome the self-weight of the valve and friction, pushing the valve flap vertically up to the full open state, the medium is unobstructed.
Valve opening height and flow rate related, the greater the flow rate, the higher the valve lift.
Reverse flow stage
When the media flow to stop or reverse flow, the valve flap in the self-weight + reverse pressure of the media under the action of the rapid descent, and the sealing surface of the valve seat close fit, blocking the media backflow.
Some models enhance the closing speed by spring assistance to reduce the risk of water hammer.
II. Structural characteristics
| subassemblies | design point |
|---|---|
| valve disc | Round or conical structure, mostly made of stainless steel or plastic (e.g. PVC), with a permanent guide bar at the bottom to ensure the accuracy of vertical movement. |
| Sealing surface of valve seat | Adopt soft seal (rubber/fluoroplastic) or hard seal (metal cladding), suitable for different media sealing needs. |
| valve body | Streamlined channel design, flanged or threaded connections, available in cast iron, stainless steel or PVC, suitable for low to medium pressure applications. |
III. Installation Requirements and Restrictions
Installation direction
Forced vertical installation: only applicable to vertical pipelines, and the medium flow direction must be from bottom to top.
Wrong installation (e.g. horizontal or reverse) will result in the valve not being able to reset properly, leading to leakage or malfunction.
Applicable Scenarios
Suitable for clean liquid or gas media, such as water supply and drainage systems, chemical low-pressure pipelines and PVC pipelines to prevent backflow control.
Not suitable for solid particles, high viscosity or corrosive media.
