Engineer IV E& at Sinclair Tulsa Refining LLC Engineer IV E& at Sinclair Tulsa Refining LLC in Tulsa, Oklahoma Posted in 15 days ago. HF Sinclair Tulsa Refining LLC in Tulsa, OK seeks an Engineer IV E&I to provide engineering support, guidance, and development assistance to colleagues in the field of instrumentation. Ensure the reliability and integrity of instrumentation systems across operating units. Up to 10% domestic travel is required. To submit resume, please apply online at . Resume must include job code 14976. recblid 8cnpk3716iy1ceplku54gn8lr227pv