Flush Plug Valve Working Principle

Flush Plug Valve is a special designed plug valve. The main feature of it is generating one or more flushing or grease injection ports, which are used for valve’s online cleaning, maintaince and sealing injection, solving the problem of easily stuck and wear under the certain working conditions of the regular plug valves.

1. Basic Structure and Working Principle
1.1 Core structure:
Body: It usually have a T or L type passage, is similar to a regular plug valve.
Plug: Conical or cylindrical plug and there is a through hole in the middle. Rotate it 90 degrees achieve the opening and closing of the valve.
Flushing/Grease System: This is the key point. At the bottom, side and top of the plug valve, there are one or multiple ports leading to the valve chamber and sealing surface. This port can connect with pressure source, like water, steam, cleaning liquid or sealing grease.

1.2 Working principle:
Normal opening and closing: Like a regular plug valve, the flush plug valve can control medium flows can be aligned or misaligned by rotating the valve stem or actuator by 90 degrees.

Flushing function: When the valve is partily open or fully closed, by inject high-pressure water, steam or chemical cleaning liquid, this can:
It can flush the solid particles, crystals, slurries or sediments which are gathered in the valve camber and around the plug.
Prevent the valve from stuck due to the accumulation of impurities and ensuring smooth operation.

Grease/Sealing Function: By injecting special sealing grease(lubricating oil) to the sealing surface through injection port. This can:
Form sealing film to fill the gap caused by wear between the plug and the valve body, improve the sealing performance, achieve "zero leakage".
Lubricate the plug surface, reduce operating torque and making switching easier.
Isolate corrosive or high-viscosity media, protecting the metal sealing surface.

2. Main Feature and Advantage
Anti-clogging and self-cleaning: The double flush plug valve is good at handling media that are prone to crystallization, scaling, or containing solid particles, such as mud, wastewater, and particulate matter, making it suitable for a wider range of applications.

Excellent sealing performance and maintainable: By regularly injecting sealing grease, it can the plug valve a good seal effect, extending valve service lifespan. Even after slight wear on the sealing surface, the seal can be restored by injecting grease.

Low operating torque: Lubricating effect of the seal grease greatly reduce the force required to operate the valve, especially for large-diameter valves.
Long service life: Effectively flushing and lubrication great reduce wear and corrosion on the flush plug and valve body sealing surface.

Online maintenance: Clean and sealing maintenance can perform without remove the valves from the pipeline, reducing downtime and maintenance costs.

3. Main Application Area
Flush plug valves is suitable for the following operating work condition:
○ Mining and Metallurgy: Pipelines for slurry, tailings, pulverized coal, dust, etc.
Wastewater Treatment: Pipelines for sewage and sludge containing large amount of impurities and solid particle.
○ Chemical Industry: Chemical media that easy to crystallize or polymerize, such as caustic soda, phosphoric acid, and slurries.
○ Paper Industry: Conveying pulp and fiber pulp.
○ Power Industry: Limestone slurry and gypsum slurry pipelines in flue gas desulfurization (FGD) systems.
○ Construction and Ceramics: Convey cement slurry and ceramic raw materials.

Flush plug valve is the upgrade of the normal plug valve, the core feature is it has the flushing and grease injection function. It can flush the impurities of the inside of the valve body, completely solve the stuck problem of the regular plug valve. At the same time, by injecting sealing grease, it can automatically repair sealing after wear. It can achieve zero leakage for a long time, and greatly reduce the torque. Compare to its slightly higher price, the overall benefits are remarkable.

In general, flush plug valve achieve a big progress compared to traditional plug valve, especially its flushing and grease injection functions. It is not a simple replace, but a enhanced tool to solve the certain industrial problems. When choosing between the flush plug valve and regular plug valve, if the medium is clean and the working condition is fine, the second one is the economic choice. But if the medium is challenging, the flush plug valve is the only option available.