<SEC-DOCUMENT>0001144204-17-008693-index.html : 20170214
<SEC-HEADER>0001144204-17-008693.hdr.sgml : 20170214
<ACCEPTANCE-DATETIME>20170214152431
ACCESSION NUMBER:		0001144204-17-008693
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20170214
DATE AS OF CHANGE:		20170214

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHWEST PIPE CO
		CENTRAL INDEX KEY:			0001001385
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL PIPE & TUBES [3317]
		IRS NUMBER:				930557988
		STATE OF INCORPORATION:			OR
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-44989
		FILM NUMBER:		17607854

	BUSINESS ADDRESS:	
		STREET 1:		5721 SE COLUMBIA WAY
		STREET 2:		SUITE 200
		CITY:			VANCOUVER
		STATE:			WA
		ZIP:			98661
		BUSINESS PHONE:		3603976250

	MAIL ADDRESS:	
		STREET 1:		5721 SE COLUMBIA WAY
		STREET 2:		SUITE 200
		CITY:			VANCOUVER
		STATE:			WA
		ZIP:			98661

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
		CENTRAL INDEX KEY:			0001644956
		IRS NUMBER:				472614791
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		222 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		312-236-1600

	MAIL ADDRESS:	
		STREET 1:		222 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>v459205_sc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: v459205_sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>