ABEC, Inc.

Agrium Inc.

Anderson Development Company

Bahrain Petroleum Company - BAPCO

BHPBilliton Nickel West

Cenovus Energy Inc.

Chemetall Foote Corp.

Chevron Phillips Chemical Company, LP

Coffeyville Resources Refining & Marketing LLC

Covidien

Emerson Process Management

Engineering for the Petroleum & Process Industries (ENPPI)

Harvest Operations Corp.

HOVENSA L.L.C.

Invista S.à r.l.

KPS Technology & Engineering LLC

Kraton Polymers

L-Con Engineers & Constructors

Lloyd Engineering, Inc.

Lyondell Chemical Company

Marafiq

Northwest Upgrading Inc.

NuStar Logistics, L.P.

ONEOK, Inc.

Petroleum Company of Trinidad and Tobago Ltd.

Plasco Energy Group

PlusPetrol S.A.

Praxair

Sasol Technology

Saudi International Petrochemical Company - SIPCHEM

Seadrift Coke L.P.

Silver Eagle Refining

Sinclair Oil Corporation

Stepan Company

Sumitomo Chemical Company, Ltd.

The Sherwin-Williams Company

Tengizchevroil (TCO)

The University of Texas at Austin Department of Utilities and Energy Management

Valero Corporate Services Company

The Williams Companies

Wink Engineering - an InServ Company

Wynnewood Refining Company