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Note 1 - Organization | 12 Months Ended
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Dec. 31, 2017
Notes to Financial Statements |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] |
1. | ORGANIZATION :
Northwest Pipe Company (collectively with its subsidiaries, t he “Company”) operates in one business segment, Water Transmission, which primarily produces steel pipeline systems for use in drinking water infrastructure and has manufacturing facilities located in Portland, Oregon; Adelanto, California; Parkersburg, West Virginia; Saginaw, Texas; St. Louis, Missouri; Salt Lake City, Utah and Monterrey, Mexico.

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