| Business | Phone |
| Assoc Pipeline Contractors 3535 Briarpark Dr 135, Houston 77042 | (713) 789-4311 |
| Amf Intl 512 Heights Blvd, Houston 77007 | (713) 863-0522 |
| Anchor Pipe Intl Inc 9310 Campbell Rd, Houston 77080 | (713) 465-8377 |
| Apache Oil & Gas Transmission 700 Louisiana St, Houston 77002 | (713) 225-4187 |
| Arguss Pipeline Svc 2626 South Loop W, Houston 77054 | (713) 839-1494 |
| Benson Pipeline Maintenance 14141 Gulf Fwy, Houston 77034 | (281) 481-2239 |
| Conestoga-Rovers & Assoc 6320 Rothway St 100, Houston 77040 | (713) 734-3090 |
| Collins Pipeline Constr Llc 11331 Charles Rd, Houston 77041 | (713) 849-4040 |
| Girard Industries 6531 N Eldridge Pkwy, Houston 77041 | (713) 466-3100 |
| Milbar Hydro-Test Inc Houston 77056 | (832) 444-3375 |
| Greene's Pipline Svc 3347 Frick Rd, Houston 77086 | (281) 820-1716 |
| Greens Pipline Svc 2207 Oil Center Ct, Houston 77073 | (281) 821-8469 |
| Gregory & Cook Inc 7575 San Felipe St 350, Houston 77063 | (713) 780-7500 |
| H H Null Inc 215 Lockwood Dr, Houston 77011 | (713) 926-8816 |
| Lyle C Reed Co Houston 77069 | (281) 580-9385 |
| Hollico Inc 12866 Nimitz St, Houston 77015 | (713) 453-0146 |
| Houston Contracting Co 2901 W Sam Houston Pkwy N, Houston 77043 | (713) 622-7919 |
| Kinsel Industries Inc 8121 Broadway St 300, Houston 77061 | (713) 641-5111 |
| Inert Gas Svc Inc 2690 Appelt Dr, Houston 77015 | (281) 457-9700 |
| Insituform Technologies Inc 16619 Aldine Westfield Rd, Houston 77032 | (713) 643-9990 |
| International Piping Products 16623 Aldine Westfield Rd, Houston 77032 | (281) 443-7171 |
| J & B Technologies Inc 13700 Veterans Mem Dr 355, Houston 77014 | (281) 440-5154 |
| Laney Directional Drilling 7615 Mount Houston Rd, Houston 77050 | (281) 987-3054 |
| Morco Testing Inc 1720 Preston St, Houston 77002 | (713) 947-1510 |