Sealing device

A fluid sealing device comprising:

• a sealing member comprising a first surface and a second surface opposite the first surface,
• a first region of the first surface for forming a first seal about a process component aperture of a process component containing a fluid, and an inner region of the first surface to be exposed to the fluid via the process component aperture,
• a restraining member providing a support surface facing the second surface to limit an amount of movement of the sealing member in a pressurized condition by contact, and a perimeter portion of the restraining member adapted to seal with a first region of the second surface, the first regions of the first surface and the second surface corresponding with a first region of the sealing member, and
• wherein the restraining member comprises an aperture through the support surface, and the sealing member further comprising a projection aligned with the aperture in the support surface and configured to extend through the aperture,
• an inner region of the second surface spaced from the support surface to form a cavity between the inner region of the second surface and the support surface at least in an unpressurised condition,
• wherein the inner regions of the first surface and the second surface correspond with an inner region of the sealing member, the inner region of the sealing member moveable towards and away from the support surface under action of a pressure of the fluid on the inner region of the first surface to provide an indication of the pressure, by moving the projection in the aperture.