A pressure seal is a valve design concept that offers distinct advantages when compared to a conventional bolted body-to-bonnet sealing mechanism. It uses the valve system pressure to provide sufficient forces against the valve body’s internal diameter (ID) and the bonnet surfaces. As the system pressure increases, the force on the pressure seal gasket also increases.
Although the only working part of the gasket is the apex or toe, the pressure seal conforms to the inside diameter of the valve. When the system pressure is activated, the toe forms a seal that can maintain thousands of pounds of pressure and keep the system media contained within the valve.
Most often, it is used for high pressure in power generation, pulp and paper, refineries and even chemical plants. Because of the reliance on system pressure to maintain a seal, these valves are best applied in systems in which the minimum operating pressure is more than 500 psi.
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