| Business | Phone |
| Dli 6911 Mayard Rd A, Houston 77041 | (713) 937-6400 |
| Metallurgical Systems Inc 5302 Chandler St, Houston 77007 | (713) 861-5773 |
| Heat Recovery Corp 1657 Oak Tree Dr, Houston 77080 | (713) 827-0202 |
| Heat Transfer Specialists Inc 2115 Cypress Landing Dr 100, Houston 77090 | (281) 580-6700 |