Rubber-Lined Diaphragm Valve

Design & structural Features
Rubber-lined diaphragm valves include weir type, straight-through, and reciprocating designs. The straight-through diaphragm valve has no weir, allowing fluid to flow directly through the valve body. This feature makes it particularly suitable for viscous fluids, cement slurry, and fluids containing sediments. Compared with weir-type valves, straight-through diaphragm valves have a longer diaphragm stroke, which limits the selection range of synthetic rubber materials for the diaphragm.
The straight-through fluid passage is linear, resulting in lower fluid resistance and reduced wear. While low-pressure operation increases diaphragm deflection and stress, it also leads to a lower pressure rating.
Rubber-lined diaphragm valves require minimal operating force and a short diaphragm stroke to open and close, reducing diaphragm disturbance, extending service life, minimizing maintenance and downtime, and lowering production costs. This makes them among the most widely used types of diaphragm valves.
Depending on the medium, the valve body can be lined with different types of rubber, and the diaphragm can be made of rubber or PTFE lined with synthetic rubber. The diaphragm is connected to the pressure-bearing sleeve, which is attached to the threaded valve stem. When closing the valve, the diaphragm is pressed down to seal against the weir-shaped structure of the body, the valve cavity contour, or another internal sealing surface, depending on the internal design.

Key Structural Features:
Elastic Sealing Element: Ensures zero internal leakage.
Streamlined Flow Path: Minimizes pressure loss.
No Packing Box: Prevents external leakage.
Separated Valve Cover: The valve cover and stem above the diaphragm are isolated from the medium, preventing corrosion of moving parts.
Replaceable Diaphragm: Lowers maintenance costs and simplifies servicing.
Variety of Lining Materials: Suitable for various media with excellent corrosion resistance.