Charging Systems Not Requiring A Permit
When performing work on the refrigerant circuit and when handling refrigerant, observe all general safety precautions and pressure canister regulations.
Charging systems not requiring a permit are ones used for transferring compressed gases to mobile compressed-gas canisters for internal use only.
Note:
Some A/C service units are charging systems not requiring a permit. When working with such equipment, the refrigerant is not transferred to mobile compressed-gas canisters, but rather into a permanently-installed charging cylinder with visible level gauge and floater switch.
Recommendation:
It is advisable to use a portable charging cylinder with visible level gauge and pressure relief valve for surplus refrigerant for internal use.
Attention must be paid to various technical regulations for compressed gases (for example TRGS 400, TRGS 402, TRGS 407 TRGS 510 TRGS 725 / TRBS3145) when transferring compressed gases to other compressed-gas canisters.