A sealing device includes a tubular central core (1, 40, 61) of generally U-shaped cross section. The central core has a degree of elasticity to deformation of its shape in a plane perpendicular to its longitudinal direction (2). A membrane (5, 41, 65) is disposed around said central core. The membrane is made of a flexible and elastic material having a much higher coefficient of elasticity than the central core. The membrane is sealed with edges of side walls (15) of the central core and at the longitudinal end of the membrane to the core to form a closed deformable chamber (8, 42, 68) of substantially crescent-shaped cross section. A fluid under pressure is admitted to the inside of the chamber (8, 42, 68).

An apparatus for blocking the flow of fluid through a conduit such as a sewer inlet or the like is provided. The flow-blocking apparatus includes an expandable bladder, a compressed-gas source for supplying compressed gas to effect expansion of the bladder, and a handle device for supporting the compressed-gas source while the bladder is positioned in the conduit to be blocked. The handle device is configured to permit an operator to actuate the flow of compressed gas to the bladder while continuing to support the compressed-gas source. The handle device preferably includes a base portion, a movable portion pivotable relative to the base portion and an actuating member movable in response to pivoting of the movable piston for controlling the flow of compressed gas from the compressed-gas source to the bladder. The apparatus also includes a burst protection plate which deflects compressed gas escaping from the bladder to thereby prevent any injury to an operator.

A plumbing tool and its method of use are disclosed wherein the plumbing tool includes a tube for insertion into a pipe beyond an area of such pipe that is to be soldered, such tube having an inflatable balloon structure at one end thereof. After the tube is inserted in the pipe and the balloon structure is positioned at the location where fluid stoppage is desired, the balloon structure is inflated to allow for soldering operations to be completed. A water bypass can be disposed within such tube for directing any fluid flow to the exterior of the pipe.

An inflatable flow control apparatus and method for controlling the flow of a fluid through a drain passage are provided. The apparatus includes an inflatable bladder with first and second opposite sides and an outer surface extending between the sides. A plurality of tubular passages extend through the bladder between the first and second sides. The bladder is configured to be inflated in the drain passage so that the outer surface is disposed against the drain passage and the fluid in the drain passage is directed through the tubular passages. The flow of the fluid through the tubular passages can be selectively controlled, e.g., by opening and closing valves connected to the passages.

A pipeline flow stopper is insertable in a collapsed, deflated form in a pipeline through a tap hole and then inflated to temporarily block fluid or gas flow through the pipeline. The stopper comprises an inner inflatable bladder encased within an outer bladder casing. The inflatable bladder receives a pressurized gas and inflates to an inflated form within the pipeline. The bladder casing is constructed of fabric coated with a flexible polymer to render the fabric impervious to the fluid or gas in the pipeline. The fabric is joined together along seams either by stitching which is thereafter sealed by liquid seam sealer, cementing, vulcanization or the like, or the stitching can be eliminated entirely and all the seams electronically heat sealed to join them and prevent fluid or gas from escaping past the stopper through the seams. The bladder casing encloses the inflatable bladder and sealingly engages with the inner wall surface of the pipeline when the inflatable bladder is inflated to seal off the pipeline. In order to assist in preventing leakage of fluid or gas past the outside of the inflated pipe flow stopper and the inside of the pipeline wall, a flexible sealing member, such as an O-ring made of soft rubber or plastic, is placed circumferentially around the outside diameter of the bladder casing for sealingly engaging with the pipeline wall.