After operating various aspects of the ammonia training system such as DX, flooded, recirculated, cascade, and water chiller, the operators in these pictures observed and controlled hot gas defrost and hot gas heating using hand expansion, dual pressure regulators, and float drainers.  The operators and instructors, including our RETA Authorized Instructor, also had thorough discussions and dialogue concerning troubleshooting and   cause / effect.  After the completion of the Operator III course, several students took the RETA’s CIRO examination.