| PIPE Fitters Local 120 | Related tax-exempt org | Provide labor benefits to members of the union | OH | 340553590 |
| PIPE Fitters Local 120 Insurance Fund | Related tax-exempt org | Provide health and welfare benefits to members | OH | 340747441 |
| PIPE Fitters Local 120 Scholarship Fund | Related tax-exempt org | Provide scholarships to dependent children of members of the union | OH | 237397291 |
| American Fire & Sprinkler LLC | Related partnership | — | — | — |
| Brett Zupka LLC | Related partnership | — | — | — |
| Crazeweld LLC | Related partnership | — | — | — |
| DSO Mechanical LLC | Related partnership | — | — | — |
| Fireline Sprinkler LLC | Related partnership | — | — | — |
| Great Lakes Piping LLC | Related partnership | — | — | — |
| Synergy LLC | Related partnership | — | — | — |
| AERO TECH Manufacturing INC | Related taxable corporation/trust | — | — | — |
| Alcon Mechanical Plumbing | Related taxable corporation/trust | — | — | — |
| Automatic Mechanical | Related taxable corporation/trust | — | — | — |
| Bassett Sprinkler | Related taxable corporation/trust | — | — | — |
| BMWC Contractors | Related taxable corporation/trust | — | — | — |
| Brewer-Garrett CO | Related taxable corporation/trust | — | — | — |
| Campbell INC | Related taxable corporation/trust | — | — | — |
| Carrier Corp | Related taxable corporation/trust | — | — | — |
| Climate PROS | Related taxable corporation/trust | — | — | — |
| Cline Mechanical INC | Related taxable corporation/trust | — | — | — |
| Coleman Spohn | Related taxable corporation/trust | — | — | — |
| Columbo Sales & ENG INC | Related taxable corporation/trust | — | — | — |
| Comunale CO SA | Related taxable corporation/trust | — | — | — |
| Conti Corp | Related taxable corporation/trust | — | — | — |
| Danner HVAC & Refrigeration | Related taxable corporation/trust | — | — | — |