This disclosure relates generally to corrugated pipe, and more particularly to corrugated pipe with an outer wrap. In one embodiment, a pipe includes an axially extended bore defined by a corrugated outer wall having axially adjacent, outwardly-extending corrugation crests, separated by corrugation valleys. The pipe also includes an outer wrap applied to the outer wall. The outer wrap may include fibers and plastic. The outer wrap may span the corrugation crests producing a smooth outer surface.

A hydropower installation includes a water supply and an energy generating station, with the supply at a higher level than the energy generating station; and a duct extending between the supply and the energy generating station. The energy generating station of the hydropower installation is configured based on high water velocity and low pressure. The duct may comprise plastic pipes. The duct may be arranged on a foam support and enclosed by a foam embedment. The duct may comprise at least two duct sections, with an intermediate energy generating station arranged between the duct sections of the duct. The duct may comprise internally extending protrusions, such as dimples to promote a laminar flow of fluid through the pipe. The duct may taper. Water pressure inside the duct may be maintained at atmospheric level. The proposed features all contribute to a pressure free velocity based system.

A heterophasic copolymer composition obtained by a process comprising polymerising in multiple steps and multiple polymerisation reactors propylene monomer and a comonomer selected from ethylene, alpha-olefins having 4 to 10 carbon atoms and their mixtures, in the presence of an olefin polymerisation catalyst comprising a solid catalyst component and a co-catalyst, wherein the solid catalyst component comprises titanium, magnesium, halogen and an internal donor of the formula (I):

##STR00001##

wherein R.sub.1 and R.sub.2 are the same or different being a linear or branched C.sub.1-C.sub.12-alkyl group and R is hydrogen or a linear, branched or cyclic C.sub.1 to C.sub.12-alkyl.

A heterophasic copolymer composition obtained by a process comprising polymerising in multiple steps and multiple polymerisation reactors propylene monomer and a comonomer selected from ethylene, alpha-olefins having 4 to 10 carbon atoms and their mixtures, in the presence of an olefin polymerisation catalyst comprising a solid catalyst component and a co-catalyst, wherein the solid catalyst component comprises titanium, magnesium, halogen and an internal donor of the formula (I):

##STR00001##

wherein R.sub.1 and R.sub.2 are the same or different being a linear or branched C.sub.1-C.sub.12-alkyl group and R is hydrogen or a linear, branched or cyclic C.sub.1 to C.sub.12-alkyl.

The present invention relates to a pipe suitable for conveying fluids in HVACR applications, which pipe comprises an inner tube delimiting an inner space or passageway for a fluid, an insulating cover and an anti-corrosion layer.

An ink supply tube includes: a first layer that is made of an unmodified ethylene-tetrafluoroethylene copolymer resin and is in contact with ink; a second layer that is made of a modified ethylene-tetrafluoroethylene copolymer resin and is formed on an outer periphery of the first layer; a third layer that is made of a polyamide resin or a basic functional group-modified polypropylene resin and is formed on an outer periphery of the second layer; a fourth layer that is made of an ethylene-vinyl alcohol copolymer resin having a gas barrier property and is formed on an outer periphery of the third layer; and a fifth layer that is made of an acid functional group-modified polypropylene resin and is formed on an outer periphery of the fourth layer.

In some embodiments, a polyethylene composition includes has 80 wt % to 99.9 wt % ethylene content and 20 wt % to 0.1 wt % a C3 to C40 α-olefin comonomer content, based on ethylene content plus comonomer content. The composition has a Mw/Mn of 15 to 45, a density of 0.93 g/cm.sup.3 to 0.97 g/cm.sup.3, a complex viscosity (at 628 rad/s, 190° C.) of 600 Pa*s or less, a zero shear viscosity by Cross model of 150,000 Pa*s to 350,000 Pa*s. It may also have a V index of less than 7. In some embodiments, an article includes the polyethylene composition. In some embodiments, the article is a pipe.

In some embodiments, a polyethylene composition includes has 80 wt % to 99.9 wt % ethylene content and 20 wt % to 0.1 wt % a C3 to C40 α-olefin comonomer content, based on ethylene content plus comonomer content. The composition has a Mw/Mn of 15 to 45, a density of 0.93 g/cm.sup.3 to 0.97 g/cm.sup.3, a complex viscosity (at 628 rad/s, 190° C.) of 600 Pa*s or less, a zero shear viscosity by Cross model of 150,000 Pa*s to 350,000 Pa*s. It may also have a V index of less than 7. In some embodiments, an article includes the polyethylene composition. In some embodiments, the article is a pipe.

A pipe bell-end ring flare device for use with a mandrel to form bell ends with a flared outer edge in plastic pipe sections either as part of the pipe manufacturing process or subsequent to the manufacturing process. The flared edge creating a wider bell end opening to make it easier to insert a non-bell end of another pipe into the flared bell end.

A sheet of material is crumpled and flattened so that it is longitudinally compressed while remaining substantially uncompressed in the lateral direction. Once so formed, the sheet may be stretched to conform to complex three-dimensional shapes. When applied to thermally insulated piping, for example, such sheets may serve as barriers to the movement of water in the insulation system.