Device for retaining rising hot air which can be vertically fitted to pipes, tubes or channels

摘要

The structure to prevent the escape of warm air and gas from vertical pipes, hoses or channels through building walls and prevent the entry of particles, has an elastic surface material (11) with a number of flaps (19) operated by a drop in pressure between the outer and inner surfaces. At least one flap has a self-return characteristic through a slit (17) at one end and a bending hinge line at the other end. The elastic material is of rubber or plastics with reinforcement.