Patent · US Expired

Multi-layered pipe

US6684910B2 · kind B2 · utility

6Cited by

9References

10Claims

0Family size

Assignee

Wavin B.V. · NL

Inventors

Jan Stoffelsma · Hoevelaken, NL
Volker Koestring · Twist, DE
Ali Guettouche · Geeste, DE
Helmut Schroeder · Wiesbaden, DE

Key dates

Filing date	Jan 6, 2003
Grant date	Feb 3, 2004
Priority date	—
Expiry date	Jan 6, 2023

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/1393
WIPO fieldSurface technology, coating
WIPO sectorChemistry

Abstract

A pipe of layers of thermoplastic polyolefins of the same type, however with different properties, which are connected inseparably with one another, an outer first layer and a second layer, adjoining the first layer on the inside, consisting of a material, which has not been cross-linked, the second layer approximately having the FNCT the value or the NPT value of a one-layer standard pressure pipe and the first layer having an FNCT or NPT value, which is higher by a factor of at least 3 than that of the second value. Moreover, a third layer is provided, which adjoins the second layer on the inside, also consists of material that is not cross-linked and has a PNCT, which is higher by a factor of at least 3 than that of the second layer and an NPT layer, which is higher by a factor of at least 2 than that of the second layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.