A four-layer-structured water passing device is provided, in which a first sleeve and a second sleeve are disposed between an elastic inner tube and an outer cloth sheath. When the water passing device is connected with a pressurized water source, the first sleeve can quickly eliminate or reduce the impact wave strength when receiving a strong expansion impact from the elastic inner tube, such that the first sleeve can gently transmit the fluctuation to the second sleeve, and the second sleeve extends the outer cloth sheath to the limit length, so as to avoid damage caused by frequent direct contact friction between the elastic inner tube and the outer cloth sheath. The water passing device is also configured to avoid permanent deformation and abrasion at the joint position between the elastic inner tube and the outer cloth sheath, and thus prolong the service life of the water passing device.

A hose is provided comprising a rubber backing layer directly bonded to a continuous polyamide layer without an intervening adhesive layer, wherein the hose exhibits increased low and high temperature capability and decreased permeation compared to standard automotive refrigerant hoses.

A flexible pipe comprising at least one layer of ethylene-vinyl alcohol resin (EVOH) as the innermost layer, wherein the pipe is suitable for use under high pressure, is configured to retain mechanical properties at pressures up to at least about 1500 psig, and can also retain its structural function upon decompression.

Provided is a method of determining whether a multilayer tubular structure (MLT) satisfies an extractables test by filling the multilayer tubular structure MLT with an alcohol-containing petrol of FAM B type to obtain a filled MLT and measuring the amount of extractable material. The MLT satisfies the extractables test when the residue of the filtrate is less than or equal to 6 g/m.sup.2 of the inner surface area of the MLT.

Multilayered motor vehicle tube, wherein the tube has at least five layers with the following layer structure from the outside to the inside: An outer layer made of at least one polymer from the group polyamide, polyolefin, a first carrier layer made of polyamide, a barrier layer made of at least one component from the group ethylene vinyl alcohol copolymer (EVOH), fluoropolymer, a second carrier layer made of polyamide, an inner layer made of a thermoplastic polyurethane (TPU).

The total layer thickness of the tube is 0.7 to 2 mm.

Use of tubing as temperature control tubing in motor vehicles, wherein a temperature control medium is passed through the tubing. The tubing has the following layer structure from the outside inward: an exterior layer of at least one polyolefin, a first adhesive barrier, a barrier layer of at least one polyamide, a second adhesive barrier and an interior layer of at least one polyolefin. The entire wall thickness of the tubing is 0.5 to 3.5 mm.

There is provided a multilayered tube for transporting liquid chemicals containing an outermost layer and an innermost layer, the innermost layer containing a polyamide (A), an impact modifier (B), and a carbon nanotube (C), wherein the number of projections each having a height of 5 m or more and a longitudinal width of 20 m or more, which are present on the surface of the innermost layer, is 2 or less per 1 mm.sup.2 of surface area; and the number of agglomerates each having a longitudinal width of 5 m or more, which are present in the cross section of the innermost layer, is 15 or less per 1 mm.sup.2 of cross-sectional area. There is also provided a polyamide resin composition constituting the innermost layer of the multilayered tube for transporting liquid chemicals.

A peelable heat-shrink tubing includes a base polymer comprising fluorinated ethylene propylene (FEP), and at least one fluoropolymer coextruded with the base polymer. The peelable heat-shrink tubing may have a haze between about 40% and 80%, inclusive, and/or a total luminous transmittance between about 70% and 85%, inclusive. In some embodiments, the haze may be between about 50% and 70%, inclusive, and/or the total luminous transmittance may be less than about 80%. The base polymer may comprise FEP NP-130 and constitute between about 87.5% and 92.5% by composition of the peelable heat-shrink tubing, inclusive, and the at least one fluoropolymer may comprise ethylene tetrafluoroethylene (ETFE) and constitute between about 7.5% and 12.5% by composition of the peelable heat-shrink tubing, inclusively. In some embodiments, the at least one fluoropolymer may comprise 7.5% of ETFE and 5% of perfluoroalkoxy alkane (PFA), each by composition of the peelable heat-shrink tubing, inclusive.

A multi-layered pipe comprising a wall having a polyolefin inner layer and a barrier layer being an outer layer relative to the polyolefin inner layer, the barrier layer being formed of a non-metallic barrier material, which barrier material has relative to polyolefin an enhanced resistance to permeation therethrough of hydrocarbon molecules, the pipe further comprising a protective layer being an outer layer relative to the barrier layer, the pipe further comprising a peelable layer between the polyolefin inner layer and the barrier layer, the peelable layer being formable around the polyolefin inner layer by means of extrusion. The protective layer and the barrier layer may together be incorporated in a single layer.

Multi-layer motor vehicle tube for conducting at least one fluid medium, in particular for conducting of motor fuels, wherein the tube comprises at least five layers, The tube features the following layer structure, from outside to inside: an outside layer made of at least one polyamide, a first adhesion-promoting layer, a barrier layer with barrier properties, a second adhesion-promoting layer, an inside layer made of at least one thermoplastic polyurethane (TPU) and/or at least one partly aromatic polyamide (PPA). The total layer thickness of the tube amounts to 0.7 to 3 mm.