The present invention is a multi-layer tube comprising at least two layers having an (a) layer containing an aliphatic polyamide composition (A) and a (b) layer containing a semi-aromatic polyamide composition (B) containing a specific semi-aromatic polyamide (B1), wherein the aliphatic polyamide composition (A) contains a specific amount of an aliphatic polyamide (A1) and a specific amount of an elastomer polymer (A2) containing an unsaturated compound having a carboxyl group and/or acid anhydride group, and the product of the terminal amino group concentration [X] of the aliphatic polyamide (A1) per g of the aliphatic polyamide composition (A) and the total concentration [Y] of the carboxyl group and acid anhydride group of the elastomer polymer (A2) per g of the aliphatic polyamide composition (A) is a specific amount.

The present invention is a multi-layer tube comprising at least two layers having an (a) layer containing an aliphatic polyamide composition (A) and a (b) layer containing a semi-aromatic polyamide composition (B) containing a specific semi-aromatic polyamide (B1), wherein the aliphatic polyamide composition (A) contains a specific amount of an aliphatic polyamide (A1) and a specific amount of an elastomer polymer (A2) containing an unsaturated compound having a carboxyl group and/or acid anhydride group, and the product of the terminal amino group concentration [X] of the aliphatic polyamide (A1) per g of the aliphatic polyamide composition (A) and the total concentration [Y] of the carboxyl group and acid anhydride group of the elastomer polymer (A2) per g of the aliphatic polyamide composition (A) is a specific amount.

This disclosure relates generally to corrugated pipe, and more particularly to corrugated pipe with a reinforcing stiffener. The corrugated pipe may include an axially extended bore defined by a corrugated outer wall having axially adjacent, outwardly-extending corrugation crests, separated by corrugation valleys. In some embodiments, a stiffener may be positioned within the corrugation valleys. In other embodiments, a stiffener may be positioned within the corrugation crests.

This disclosure relates generally to corrugated pipe, and more particularly to corrugated pipe with a reinforcing stiffener. The corrugated pipe may include an axially extended bore defined by a corrugated outer wall having axially adjacent, outwardly-extending corrugation crests, separated by corrugation valleys. In some embodiments, a stiffener may be positioned within the corrugation valleys. In other embodiments, a stiffener may be positioned within the corrugation crests.

Disclosed is a fluid transport pipe which has an inner layer, coming in contact with a fluid, comprising at least one aliphatic polyamide and at least one impact modifier and also at least one outer layer which is connected directly to the inner layer and is formed from an aliphatic polyamide and at least one flame retardant. While the inner layer ensures the chemical resistance relative to the fluids to be transported and the mechanical resistance, the flame resistance is ensured by the outer layer.

Disclosed is a fluid transport pipe which has an inner layer, coming in contact with a fluid, comprising at least one aliphatic polyamide and at least one impact modifier and also at least one outer layer which is connected directly to the inner layer and is formed from an aliphatic polyamide and at least one flame retardant. While the inner layer ensures the chemical resistance relative to the fluids to be transported and the mechanical resistance, the flame resistance is ensured by the outer layer.

A pipe or fitting having a polymer liner and a replaceable component including an outer ring having an outside diameter matching the inside diameter of the pipe or fitting, a polymer liner bonded to the outer ring and having an inside diameter matching the inside diameter of the liner of the pipe or fitting. The replaceable component is disposed in an inlet or outlet of the pipe or fitting so as to form a continuous bore lined with a polymer.

A pipe or fitting having a polymer liner and a replaceable component including an outer ring having an outside diameter matching the inside diameter of the pipe or fitting, a polymer liner bonded to the outer ring and having an inside diameter matching the inside diameter of the liner of the pipe or fitting. The replaceable component is disposed in an inlet or outlet of the pipe or fitting so as to form a continuous bore lined with a polymer.

A webless corrugated dual wall foundation drain which is constructed as a hollow rectangular tubular member with an inner corrugated wall formed of HDPE and an integral outer smooth wall formed of the same material. The outer smooth wall of the foundation drain is attached to and integrally formed with the corrugations of the inner corrugated wall through a coextrusion process, thereby significantly enhancing the vertical beam stiffness of the foundation drain and eliminating the need for an internal supporting web.

A webless corrugated dual wall foundation drain which is constructed as a hollow rectangular tubular member with an inner corrugated wall formed of HDPE and an integral outer smooth wall formed of the same material. The outer smooth wall of the foundation drain is attached to and integrally formed with the corrugations of the inner corrugated wall through a coextrusion process, thereby significantly enhancing the vertical beam stiffness of the foundation drain and eliminating the need for an internal supporting web.