Waterproof Tests Against Drops Under Extreme Pressure

High-pressure sealing usually means trapping liquids at pressures above 5.000 psi. Below these pressures, standard energized urethane lip seals and U-bottom seals operate satisfactorily without special provisions. Above them, some kind of special sealing device is required. To be effective, seals must perform these three basic functions:

• There should be sealing elements. The seals must be close enough to the microscopic irregularities of the mating surfaces to prevent the entry or passage of pressurized fluid.
• It should be adjusted for clearance or clearance changes. The gasket must have sufficient flexibility to accommodate changes in the distance between mating surfaces during a cylinder stroke. This gap spacing changes size due to differences in roundness and diameter of the cylinder parts. The gap spacing can also change size in response to side loads. As the size of the cavity changes, the gasket must match the size change to maintain the compressive sealing force against adjacent mating surfaces.
• They must resist extrusion. The gasket must resist shear forces caused by the pressure difference between the pressurized and unpressurized sides of the gasket. These shear forces work to push the elastomeric seal into the gap between adjacent metal surfaces. The gasket must have sufficient strength and stiffness to resist deformation and damage or destruction to the cavity.

Elastomeric materials must also seal while adapting to dimensional changes caused by manufacturing tolerances, side loads, and cylinder deformation under pressure. In general, sealing improves as fluid pressures increase. System pressure on the gasket surface tries to compress the gasket axially. This compression forces the gasket tighter into the union and helps increase the gasket's compatibility with the metal surfaces in contact.

The difficulties caused by high pressure are not primarily sealing problems. As increased system pressures force the seal into the cavity, they are a problem of keeping the seal in its union while maintaining its structural integrity.

The ability of a gasket to resist a gap depends on the interaction of: system operating pressure, system operating temperature, size and type of gap gap, gasket material, and gasket design.

Our organization also provides waterproof testing services against drops under extreme pressure, with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.