| DRAIN AID LIMITED | Private company limited by shares | Dissolved |
| DRAIN AID LIMITED | Private company limited by shares | Live |
| HUNTINGDON SEWER DRAIN AND PIPE CLEANING SERVICES COMPANY LIMITED | Private company limited by shares | Dissolved |
| DRAIN WORKS LIMITED | Private company limited by shares | Live |
| FU TAT DRAINAGE CO. LIMITED | Private company limited by shares | Live |
| STT DRAINAGE LIMITED | Private company limited by shares | Live |
| Kin Ming Drainage CCTV Limited | Private company limited by shares | Live |
| CHIN NGAI DRAINAGE COMPANY LIMITED | Private company limited by shares | Dissolved |
| KIN MING DRAINAGE LIMITED | Private company limited by shares | Dissolved |
| PACKAGE DRAINAGE LIMITED | Private company limited by shares | Live |
| NEW DRAGON DRAINAGE SERVICE COMPANY LIMITED | Private company limited by shares | Live |
| Sunning Drainage Limited | Private company limited by shares | Live |
| DRAIN-TECH LIMITED | Private company limited by shares | Dissolved |