It is the responsibility of the _____ to furnish documentation certifying that all installed piping materials are cleaned for oxygen service.

The responsibility for furnishing documentation certifying that all installed piping materials are cleaned for oxygen service lies with the installer. This is because the installer is directly involved in the installation of the medical gas systems and must ensure that all components are properly cleaned and safe for oxygen service. Oxygen enrichment can lead to hazardous situations if materials are not adequately prepared, which makes it crucial for the installer to follow industry standards and protocols for cleaning.

Moreover, as part of the installation process, the installer is typically required to provide documentation that verifies compliance with relevant safety and cleanliness standards. This documentation serves as proof that the materials used for the system are suitable and safe for transporting medical gases, thereby ensuring patient safety and system reliability. The installer is trained to understand these requirements and execute them as part of their responsibilities.