Air Liquide
Air Products & Chemicals, Inc.
Alon USA
Amerada Hess Corporation
Anadarko Petroleum
Aquila
Baker Petrolite
BASF Corporation
Black & Veatch Pritchard
BP
Buckeye Pipeline
Burns & McDonnell
Cabot Corporation
CBI
CDI Engineering Group
Cemex
ChevronTexaco
Chevron Unocal
CITGO
Colorado Interstate Gas
Compressor Systems, Inc.
ConocoPhillips
Devon Energy
Dresser Rand
Duke
EDI
Elk Corporation
El Paso
Englehard Corporation
Enogex
Enterprise Products
Equilon
ExxonMobil
Faskin Oil
Frontier Energy
General Electric
Giant Refining
Goodyear
Gulf Chemical and Metallurgical
Gulf Coast Waste Disposal Authority
 

Halliburton
Holly Refining
Huntsman Corporation
Kaneka Texas Corporation
KOCH Partners
Lyondell Refining Co., Ltd.
Lyondell Equistar
Marathon Ashland Petroleum
Marathon Oil
Messer Industries
Navajo Refining
Occidental Petroleum
Odfjell
Ortloff Engineers, Ltd.
OXY USA, Inc.
Pasadena Refining System Inc.
Praxair
Ranch Cryogenics
Rohmax USA Inc.
S&B Engineers & Constructors
Schenectady International, Inc.
Shell Chemical
Shell Refining
Shell Oil Company
Shell Pipeline
Shell Transportation
Sid Richardson Gasoline Company
Targa Resources
Tennessee Gas Processing USA
Tesoro
Tri Gas
txi
TXU Electric
Union Carbide
Unocal
US Gypsum
US Intec
Valero
Western Gas Resources, Inc.
Williams Field Services
XTO