Abstract: A portable flood barrier section is located on a ground (2) to form a barrier (3) against flooding water (4), comprising an erectable wall (5) which along one of its edges (6) is hinged to a basis. The hinge (7) enables a rotating erection (A) of the wall (5) from an essentially horizontal position to an erected position. A flexible or rigid tie (8, 9), which extends from the basis to the wall (5) on the flooded side (10) of the wall (5), prevents an erection of the wall (5) beyond the erected position. A seal (12) is in the erected position of the flood barrier section (1) located between the flood barrier section and the ground (2). The flood barrier section (1) is adapted to, prior to flooding, to expose the seal (12) to a positive sealing pressure exceeding a pressure caused by the weight of the flood barrier section (1). The invention also relates to a flood barrier (3) comprising flood barrier sections (1).

Abstract: The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe areation, hinges, and bladder manufacture technology are disclosed herein.

Abstract: A Sediment control devices and systems generally includes a core made up of granular material encased within a puncture resistant fabric, a compressible layer enwrapping the core and a geotextile fabric outer casing. A plurality of such devices provide a system for controlling erosion and sedimentation.

Abstract: A system for anchoring fabric panels having an anchor housing which includes, a base, walls on the ends of the base, a chamber, and an extension attached to the first wall, wherein the extension projects over the chamber. The system includes a key disposed in the chamber of the anchor housing adjacent to a wall, wherein the key comprises a locking edge, a chock disposed in the chamber adjacent to the key, wherein the chock has a locking edge that engages the locking edge of the key, a deformable tube disposed in the chamber of the anchor housing between the first wall and the chock and beneath the extension, and wherein a space is created between the tube and the extension. A fabric panel attached to a mooring which is located in the space, and wherein the fabric panel extends from the mooring and over the extension.

Abstract: A portable flood water barrier system is disclosed having one or more portable, attachable, flexible modules. Each module comprises an elongated tubular member sealed at either end by rigid, flanged end caps. Each module is provided with one or more openings to permit the introduction of water, sand or similar material into the tubular member interior cavity. Each module is also provided with one or more sealable openings to permit any water, sand or similar material to be removed from the tubular member interior cavity. The material provides weight the module to hold it in position against the force of the moving floodwaters. With the tubular member interior cavity partially filled with the material the portion of the tubular member in contact with the ground substantially conform in shape to the ground contours to minimize any water seepage under the tubular member.

Abstract: Sediment control devices and systems are provided. The device generally includes a core made up of granular material encased within a puncture resistant fabric, a compressible layer enwrapping the core and a geotextile fabric outer casing. A plurality of such devices provide a system for controlling erosion and sedimentation.

Abstract: Every year, during the summer and fall seasons, we experience heavy rainfall and floods. Whenever we have heavy rainfalls, we worry about the streets flooding and the safety of the levees. The flooding of streets and cities results in the loss of human life, as well as a loss in millions of dollars of property. The mobile levee system will protect the streets, properties, and cities from flood. It is easy and quick to install, and it is more secure than sand bags. The mobile levee system will protect millions of dollars in property as well as save human lives.

Abstract: A tractor carries a vertically adjustable frame supporting a horizontal shaft for a supply roll of silt fence fabric. A vertical plow blade is mounted on the frame, and a vertical fin is supported directly behind the plow blade by a horizontal fabric guide bar attached to the frame. The fin receives an intermediate portion of the fabric directed around the guide bar for folding an edge portion of the fabric into a slot formed within the ground by the plow blade. The frame also supports a hydraulically actuated stake driver rearwardly of the supply roll and directly above the folded edge portion of the fabric. In one form, the stake driver comprises a vertically sliding ram having wide steps for receiving different length stakes. In another form, the stake driver comprises an impact hammer attached to a vertically and horizontally adjustable boom carried by the frame.

Abstract: A water structure formed from at least a pair of sleeves from a puncture resistant flexible material joined along common longitudinal surfaces, as by sewing, and include sleeve ends that are formed into closed to maintain closed-off ends of water filled tubes, and including an arrangement, such as an outer sleeve, for maintaining the pair of sleeves in side by side relationship and/or may includes at least one ground sheet for anchoring the water structure.

Abstract: A water structure that includes at least a pair of sleeves formed from a puncture resistant flexible material that are joined to one another along common longitudinal surfaces, as by sewing, and include sleeve ends that are formed into closures to contain and maintain closed-off ends of water filled tubes that are individually contained in each sleeve, and including an arrangement, such as an outer sleeve, for maintaining said pair of sleeves in side by side relationship, resisting movement when subjected to transverse forces as by wave action in a body of water maintained by the water structure.

Abstract: A rapidly deployable breakwater is disclosed having a primary barrier containing liquid under pressure, and one or more overtopping barriers. The primary barrier floats at, and extends substantially below, the surface of the water, while the overtopping barriers are positioned on the primary barrier and extend substantially above the surface of the water, the combination being adapted to attenuate wave action in open water. The liquid in the primary barrier is pressurized to a level substantially greater than the pressure of the surrounding water, and such pressure may be maintained or varied during the period of deployment of the breakwater.

Abstract: In a method for providing a portable flood barrier (1), flood barrier sections (2, 3, 4) comprising two parallel, spaced apart, inflatable, elongated tubes (5,6 or 5,7) which are joined by a waterproof web (8) are placed on the ground (9) with the side of one of the tubes (6 or 7) facing the flooded area (10), and the other tube (5) facing away from the flooded area (10). Both tubes (5,6 or 5,7) are inflated, and ballast water (13) is filled on the web (8), whereupon, when floodwater (14) rises, the tube (6 or 7) facing the flooded area (10) floats in the floodwater (14) and due to its buoyancy rises, thereby forming a flood barrier (1).

Abstract: A flood control barrier for separating water in a wet area from an area to be maintained substantially dry comprises a flexible exterior membrane made of liquid impervious material and including elongated upper and lower membrane sections joined at a closed longitudinal downstream end of the exterior membrane opposed to an open longitudinal upstream end thereof. The upper and lower membrane sections are connected by internal partition walls and are displaceable between expanded and collapsed positions, wherein in the collapsed position, the upper membrane section overlies the lower membrane section, whereas in the expanded position, the upper membrane section is spaced from the lower membrane section at the open end of the exterior membrane such that water may flow through the open end and be received between the upper and lower membrane sections such as to be trapped therein, i.e. by the closed downstream end thereof which prevents the water from flowing past the barrier.

Abstract: A barrier device includes a first containment chamber and a second containment chamber. The first containment chamber is secured to the second containment chamber by a connector. A barrier wall includes a first barrier device having a first containment chamber, a second containment chamber, and a connector. A containment chamber of a second barrier device is positioned between the first containment chamber and the second containment chamber and is positioned in overlying relationship to the connector. A barrier wall is built by positioning a first barrier device, having a first containment chamber, a second containment chamber, and a connector on a support surface. A containment chamber of a second barrier device is positioned between the first containment chamber and the second containment chamber of the first barrier device and overlying the connector.

Abstract: A method of constructing a section of an elongated dike comprises the following steps: First, an uninflated tube is positioned along an axis. Second, a strap is positioned at a first end along a second axis. Third, the strap is disposed subjacent to the first tube. The portion of the strap extending from the first tube defines a free portion of the strap. Fourth, the first tube is inflated with liquid. Fifth, a second tube is positioned parallel to and along side the first tube, opposite the first end of the strap. Sixth, the free portion of the strap Is disposed over the top of, down and subjacent the second tube and disposed over the top of the first tube. Seventh, the free portion of the strap is loosely coupled with a first buckle. Eighth, the second tube is inflated. Finally, the strap is tightened to secure the tubes together.

Abstract: A rapid emergency dam is disclosed. During adverse weather conditions heavy rain can lead to rivers breaking their banks and lakes overflowing causing flooding to the surrounding countryside. Coastline defenses can also be breached by increased sea swell and large waves. A fluid barrier section (1) of the present invention comprises an elongate rectangular fluid barrier sheet 2, an apron 4 extending from the lowermost edge 6 of the fluid barrier (2), an elongate rectangular front panel (7) and support means in the form of a plurality of support ribs (8). The fluid barrier sheet (2) is of a flexible fluid impermeable material such as plastics, rubber, waterproof canvas, nylons or any other suitable natural or man made material. A preferred material for the barrier sheet (2) is a fluid impermeable tear resistant flexible foil. In one preferred embodiment of the present invention the lowermost edge (6) of the fluid barrier is bonded to one edge of the apron (4).

Abstract: A flood control system including a substantially rigid exterior shell and a flexible bladder having one or more valves for introducing and removing a desired amount of fluid, the shell including opposite first and second rigid sides hingedly connected to one another to permit the shell to be positioned in a desired orientation exterior to and substantially overlying the flexible bladder.

Abstract: A portable flood control revetment comprising an elongated collapsible and inflatable tube of flexible material impervious to air and water, the tube having a bottom wall and other walls defining an internal compartment, and a multiplicity of cables in the compartment, each extending from one of the walls to another of the walls to hold the tube in a selected shape when the tube is filled with air or water. The bottom wall defines at least one pocket for receiving a corresponding at least one hold-down member, and other of the walls are provided with closeable orifices for permitting flow of air and water into and out of the compartment to respectively inflate, fill, and collapse the tube.

Abstract: A liquid filled dike is described. The dike is formed of a flexible material selected to contain water. The dike includes at least two bladders which extend at least a portion of the length of the dike. The dike can be transported in empty condition and filled on site. When it is no longer required at a particular site, the dike can be emptied and stored for later use. The dike is self-leveling and may include a leak detection system.

Abstract: A fitting structural body, fittings included in the structural body, and a flexible sheet inflatable gate installed inside a culvert using the structural body are disclosed. In the fitting structural body, a first fitting element and a second fitting element are respectively made into one body at corner portions of the structural body. At each corner portion, no gap between each set of fittings, and no acute parts contacting an upper sheet of the gate exist.

Abstract: A portable flood control revetment comprising an elongated collapsible and inflatable tube of flexible material impervious to air and water, the tube having a bottom wall and other walls defining an internal compartment, and a multiplicity of cables in the compartment, each extending from one of the walls to another of the walls to hold the tube in a selected shape when the tube is filled with air or water. The bottom wall defines at least one pocket for receiving a corresponding at least one hold-down member, and other of the walls are provided with closeable orifices for permitting flow of air and water into and out of the compartment to respectively inflate, fill, and collapse the tube.

Abstract: A structure for detecting an inflated state of a dam formed by a flexible membrane disposed in a conduit, with the detection unaffected by pressure resulting from fluid flow through the conduit when the flexible membrane is not completely inflated. The structure includes a metal plate mountable at a center of the flexible membrane and covered by a covering sheet and a metal detector for detecting the metal member only when the flexible membrane has been inflated to a desired state.

Abstract: The invention comprises frame members for use as a portable dam. Each frame structure is comprised of a support beam, a base beam and at least one brace beam connected together in pivoting relationship so that the beams may be folded down together for quick assembly and disassembly. The collapsed beams are configured to lie parallel to each other in a folded arrangement to permit efficiency in stacking multiple units together for storage and transportation. The erected frame structures are connected to each other and held in a spaced relationship through the use of couplers that are adapted to slide over the ends of the beams forming the frame structures. The individual frame structures may be erected in place in the water, or a section comprising several connected frame structures may be pre-fabricated and lifted and placed as a unit in the water. A stiffener member is affixed to adjacent frame structures to hold them together in rigid relationship.

Abstract: The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe aeration, hinges, and bladder manufacture technology are some of the advancements disclosed herein.

Abstract: A set of elements for erecting a transportable dam, the set comprising at least a first inflatable flexible element which, in an inflated state, forms a tube, and a filler element, which is mountable to one end of the inflatable element, whereby, when mounted to the inflatable element, the filler element defines a first end of the tube. The filler element has at least one filler plug opening for filling air and/or liquid into the inflatable element. A coupling arrangement is provided for defining a second end of the tube. The invention further relates to a method of erecting a transportable dam.

Abstract: The present invention relates to methods of attenuating underwater transmission of sound or shock waves as well as boom systems designed for such use. The boom system is characterized by a material (e.g., curtain or combination curtain and skirt) which extends substantially the entire water column when placed in a body of water, thereby defining a perimeter and a gas injection system which includes a plurality of outlets which are positioned between the perimeter and the site of underwater activity. In use, the boom system is installed such that it surrounds the site of underwater activity and then gas is injected into the water through the plurality of outlets to form a gas curtain during performance of an underwater activity capable of generating sound or shock waves.

Abstract: An artificial roof unit and method of forming it under water on a base includes locating a tube of a flexible material divided by dividing walls of a flexible material into an array of compartments running the length of the tube, with a first end of the tube on the base and a second end of the tube above the first end of the tube and under water, securing the tube in position on the base using flexible or rigid elements attached to the base; and partially filling some of the compartments with a filler material so that some of the compartments are adjacent two or more other compartments filled with a filler material to support and be supported by the adjacent compartments. The artificial reef unit may be designed to promote an increase in marine life, or to protect a shore line or harbor wall from damage.

Abstract: A flood control barrier for separating water in a wet area from an area to be maintained substantially dry comprises a flexible exterior membrane made of liquid impervious material and including elongated upper and lower membrane sections joined at a closed longitudinal downstream end of the exterior membrane opposed to an open longitudinal upstream end thereof. The upper and lower membrane sections are connected by internal partition walls and are displaceable between expanded and collapsed positions, wherein in the expanded position, the upper membrane section is spaced from the lower membrane section at the open end of the exterior membrane such that water may flow through the open end and be received between the upper and lower membrane sections such as to be trapped therein, i.e. by the closed downstream end thereof which prevents the water from flowing past the barrier.

Abstract: A precaution hose is a hollow cylindrical body made of waterproof material with a length thereof being cut as the actual need. Two seal plates are attached to the two ends of the cylindrical body respectively. A valve is mounted to the cylindrical body. The seal plates are touched to the edges of a gap thereof tightly and the cylindrical body is filled with the liquid till being full completely so that a lower part of the cylindrical body can press against the floor due to an inner liquid pressure to keep the floodwater out.

Abstract: A structure for detecting an inflated state of a dam formed by a flexible membrane disposed in a conduit, with the detection unaffected by pressure resulting from fluid flow through the conduit when the flexible membrane is not completely inflated. The structure includes a metal plate mountable at a center of the flexible membrane and covered by a covering sheet and a metal detector for detecting the metal member only when the flexible membrane has been inflated to a desired state.

Abstract: A water structure formed from at least one flexible tube or sleeve, that functions as a water containment vessel when at least partially filled with water and closed at its ends, and includes a rope positioned therein. The rope is for connection, on one end, to a second flexible tube or sleeve and is for use in pulling the second flexible tube or sleeve through the first tube or sleeve. The second tube is then to receive a volume of water therein, that expands the second tube against the first tube inner surface to function as a water structure.

Abstract: There is provided an internal pressure regulating system in which when a flexible bag body used for a collapsible dam is excessively pressurized, gas within the bag body is discharged. The system includes a flexible bag body which can be inflated with gas, and a pipe having opposite ends, with one end connected to an exhaust opening in the bag body, and the other end introduced into the upstream region of a watercourse.

Abstract: A flood protection device, system and method. The flood protection device consists of an elongated liquid-tight container, which may be filled through a nozzle thereon. The container is secured to the ground where needed by at least one stake, which stake is coupled to at least one eyelet located on the container. The container is preferably formed of polyvinyl chloride. The container may be filled, and emptied, on-site.

Abstract: A length of material, such as woven polyethylene, woven polypropylene, burlap, or other woven material, divided into a series of two or more substantially equal sized sections. Every other section is filled with sand, or other material. When the length of material is put in place, each row alternating a filled section and an unfilled section, a very secure, interlocking, substantially water-tight structure is formed which is much more effective in preventing the flow of water, mud or silt. Because each section is substantially square, the sections can be stacked in a parallel or transverse direction, to effect a wider and stronger structure which is substantially impervious to the flow of water, mud or silt.

Abstract: A rapidly deployable breakwater is disclosed having a primary barrier containing liquid under pressure, and one or more overtopping barriers. The primary barrier floats at, and extends substantially below, the surface of the water, while the overtopping barriers are positioned on the primary barrier and extend substantially above the surface of the water, the combination being adapted to attenuate wave action in open water. The liquid in the primary barrier is pressurized to a level substantially greater than the pressure of the surrounding water, and such pressure may be maintained or varied during the period of deployment of the breakwater.

Abstract: The present invention relates to a system for maintaining a surcharge on a sanitary sewer collection system to minimize the pressure differential across conduit walls and to offset the buoyant effects of hydrostatic pressure on the outside of the pipe. Pinch valves or other remotely controllable pipe closing means are employed in combination with a system of monitors and a centralized control system to maintain and periodically release fluid from the surcharged system.

Abstract: A fitting structural body, fittings included in the structural body, and a flexible sheet inflatable gate installed inside a culvert using the structural body are disclosed. In the fitting structural body, a first fitting element and a second fitting element are respectively made into one body at corner portions of the structural body. At each corner portion, no gap between each set of fittings, and no acute parts contacting an upper sheet of the gate exist.

Abstract: A flood control barrier for separating water in a wet area from an area to be maintained substantially dry comprises a flexible exterior membrane made of liquid impervious material and including elongated upper and lower membrane sections joined at a closed longitudinal downstream end of the exterior membrane opposed to an open longitudinal upstream end thereof. The upper and lower membrane sections are connected by internal partition walls and are displaceable between expanded and collapsed positions, wherein in the collapsed position, the upper membrane section overlies the lower membrane section, whereas in the expanded position, the upper membrane section is spaced from the lower membrane section at the open end of the exterior membrane such that water may flow through the open end and be received between the upper and lower membrane sections such as to be trapped therein, i.e. by the closed downstream end thereof which prevents the water from flowing past the barrier.

Abstract: A water structure formed from a pair of flexible tubes or sleeves that each receive a volume of water and are maintained within a containment sleeve, and including a vertical tube fitted through the containing sleeve to pass between and is separated from the water filled flexible tubes or sleeves.

Abstract: A flexible membrane dam is provided which can be installed easily and in which a concentration of stress at a time the dam is made to stand is less than in conventional structures. Mounting hardware for the dam is also provided. When a fluid such as air is supplied to an interior of a flexible membrane, the flexible membrane inflates and stands, and tension acts on the flexible membrane . At inclined surface portions, a vicinity of an outer peripheral edge of the flexible membrane is, in a convex and concave shape, nipped and fixed between an upper pressing hardware and a lower pressing hardware . At the upper pressing hardware, a ratio (AE1/AE1′)×100 of a length AE1 from a point E1 of a concave portion to a point A, to a length AE1′ from a point E1′ of a convex portion to the point A, is 85 or more. Namely, the length AE1′ is close to the length AE1.

Abstract: A method of manufacturing a rubber weir main body, which manufactures a rubber weir main body intended to rise by the flow-in of a fluid and to fall by the discharge of the fluid by integrally bonding at least two main body segments divided in the circumferential direction to each other, including the steps of: forming a material removed portion with stepped portions at edges of the rubber weir main body segments previously manufactured; abutting the rubber weir main body segments on each other at the edges; laminating unvulcanized rubber sheets containing reinforcing canvasses and an unvulcanized rubber sheet on the material removed portion formed between both the rubber weir main body segments contacted with each other; and integrally vulcanizing and bonding them. With this method, a large sized rubber weir main body excellent in quality can be easily manufactured at a job site.

Abstract: A method of protecting and improving the quality of water in a body of water which comprises identifying areas of water runoff and/or points of storm water entrance into the body of water and the provision of floating booms to separate a small area(s) of a reservoir where surface and storm water run-off from the water shed or storm water entrance points enter the main body of water. Supported from the booms is a filter curtain of geosynthetic fabric material which is anchored to the floor of the reservoir along the profile of the reservoir floor. The fabric material has small openings in sufficient number to permit passage of a predetermined volume of water per unit time, but small enough to block particulate biodegradable organic particulate matter. The run off or storm discharge contains particulate matter, which is a carrier of microorganisms as small as one micron. The filter curtain prevents passage of the particulate matter and non-organic turbidity causing particles.

Abstract: A flood control barrier for separating water in a wet area from an area to be maintained substantially dry comprises a flexible exterior membrane made of liquid impervious material and including elongated upper and lower membrane sections joined at a closed longitudinal downstream end of the exterior membrane opposed to an open longitudinal upstream end thereof. The upper and lower membrane sections are connected by internal partition walls and are displaceable between expanded and collapsed positions, wherein in the collapsed position, the upper membrane section overlies the lower membrane section, whereas in the expanded position, the upper membrane section is spaced from the lower membrane section at the open end of the exterior membrane such that water may flow through the open end and be received between the upper and lower membrane sections such as to be trapped therein, i.e. by the closed downstream end thereof which prevents the water from flowing past the barrier.

Abstract: There is provided an internal pressure regulating system in which when a flexible bag body used for a collapsible dam is excessively pressurized, gas within the bag body is discharged. The system includes a flexible bag body which can be inflated with gas, and a pipe having opposite ends, with one end connected to an exhaust opening in the bag body, and the other end introduced into the upstream region of a watercourse.

Abstract: An artificial reef comprises at least one bag which is generally configured to define at least a portion of a reef and which is at least partially fillable with air. An anchor is attached to the bag for maintaining the bag at a desired location substantially underwater. A plurality of such bags may be attached to one another and configured so as to define a reef which enhances the suitability of waves for surfing or which mitigates beach erosion.

Abstract: A protective device for flooding, comprising a protective cloth provided in a housing and a float connected to the protective cloth. The housing is formed as boxes having elongated sides and open gable ends. Side edges of the protective cloth in the housing are connected to one another for providing a waterproof connection to protective cloths of adjacent housings. A protective cloth for flooding comprises at least one float provided along an edge of the protective cloth, and float elements are provided spaced apart along the surface of the protective cloth.

Abstract: A flexible film, of which a flexible film weir is composed, has a two-dimensional configuration when expanded, and the total length of the periphery of the flexible film is set longer than the mounting length of mounting faces (a river bed and faces of slopes). Weights are attached on the flexible film at appropriate intervals. Portions left redundant when the flexible film is mounted on the mounting faces are folded and fixed at toes of the slopes in such a way that they are overlapped. The two-dimensional configuration of the flexible film simplifies the structure. Further, as the weights prevents the weir from floating up, there is no need for forming irregularities on the river bed, thereby simplifying the construction.

Abstract: A system and method for rapid construction of temporary watertight barriers and walls by unskilled labor which comprise stacked tiers of fluid-filled water bag assemblies. Each water bag assembly comprises a rigid outer frame and a rugged, flexible waterproof bag. The outer frame is separable into a top panel having downwardly extending pivotally-attached connection rods and a bottom panel having upwardly extending pivotally-attached connection tubes. When opposed connection rods and tubes are joined and fixed together with quickly applied fasteners, a waterproof bag placed therebetween becomes sandwiched between the top and bottom panels. Two hose connections on each waterproof bag surface provide conveniently accessed fluid introduction and air vent openings for use in draining and filling them. A standard garden hose or water pump may be used to drain or fill the waterproof bags.

Abstract: Tubular structures are described which are composed of multiple layers of reinforced material. The structures include at least one terminal end portion which includes one or more wedges between adjacent layers of reinforced material. The structures may be, for example, hoses, expansion joints, or actuators (e.g., air springs). The terminal end portions can be readily clamped together to make appropriate connections, or a terminal end portion can be clamped to a desired mounting surface.

Abstract: A flexible membrane inflating structural body is fixed to a structure such as a bed and slope sides of a waterway by using a mounting metal fitting comprising a first metal fitting and a second metal fitting. The flexible membrane inflating structural body is erected by supplying a fluid to an interior of a flexible membrane, and is deflated by discharging the fluid within the flexible membrane. The first metal fitting is disposed at a side of the structure at which the flexible membrane inflating structural body is provided and contacts one surface of the flexible membrane. The second metal fitting contacts another surface of the flexible membrane and, together with the first metal fitting, sandwiches a portion of the flexible membrane in a vicinity of an outer peripheral edge of the flexible membrane. The first and second metal fittings, which form the mounting metal fitting, each include at least one convex portion which bends the flexible membrane while the flexible membrane is in a held state.