CARO Study Guide 2026
Everything you need to pass the CARO exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 CARO Exam Format at a Glance
📚 CARO Topics to Study (69)
✍️ Sample CARO Questions & Answers
1. When draining oil from an ammonia vessel, which practice is safest?
A spring-loaded valve shuts if released, and constant attendance keeps an ammonia release from going unnoticed.
2. Before opening a section of ammonia piping for maintenance, which step is required first?
Isolating, evacuating, and applying lockout/tagout protects workers from releases of energy and ammonia.
3. Why is it important to pitch refrigerant suction lines toward the compressor?
Suction lines are pitched toward the compressor so that oil and any liquid refrigerant flow back naturally, preventing oil logging in the evaporator and liquid slugging in the compressor.
4. Increasing the clearance volume in a reciprocating compressor cylinder will:
Gas trapped in the clearance space re-expands on the suction stroke, so less fresh suction gas enters each cylinder.
5. Where must ammonia pressure relief valves on a system ultimately discharge?
Relief discharge must be piped to a safe outdoor location away from people, openings, and air intakes.
6. An operator measures a condenser pressure that is well above the saturation pressure for the liquid temperature leaving the condenser. What does this most likely indicate?
Pressure above the saturation pressure at the measured temperature points to air or other noncondensables in the condenser.