Training Objective and Scenario
📌 The training module aims to prepare participants for obtaining the refrigerant fluid handling aptitude certificate (Category I), adhering to current regulations.
⚙️ The core practical scenario involves replacing a leaking filter-drier in a refrigeration installation.
🔧 Required tasks include: brazing/unbrazing service valves, recovering refrigerant, repairing the fault, pressure testing with nitrogen, vacuuming, recharging, and leak detection using an electronic detector.

Refrigeration System Components Overview
1️⃣ The schematic identifies key components in order: Compressor (1), Condenser (2), Liquid Receiver (8), Filter-Drier (7 - the component to be replaced), Liquid Sight Glass (6), Solenoid Valve (5), Expansion Valve (4), and Evaporator (3) inside the cold room.
💨 The refrigeration cycle involves gas leaving the compressor, cooling in the condenser, becoming liquid, passing through the filter-drier, then expanding in the evaporator to cool the chamber, and returning as a gas to the compressor.
🔧 Service valves (marked 'H' and with a green arrow) are essential for maintenance and diagnostics, featuring two pressure ports.

Service Valve Functionality and Positions
⚙️ The service valve has two pressure taps: one for permanent safety devices (like HP/LP pressostats) and one for connecting the manifold gauges to read HP and LP pressures.
🔧 The valve's operation is controlled by the adjustment stem/square drive (handle mechanism), which moves the pintle/needle (5).
🔄 The valve offers three primary positions achieved by turning the square drive (6):
1. Rear Set Position (Cale Arrière): Achieved by unscrewing (counter-clockwise); the gauge connection is inaccessible.
2. Reading Position (Cale de Lecture): Achieved by screwing (clockwise); the pintle moves slightly, opening the path to the manifold pressure tap for measuring HP/LP.
3. Front Set Position (Cale Avant): Achieved by screwing completely closed; this fully obstructs the line, stopping refrigerant flow.

Key Points & Insights
➡️ The primary focus is mastering the procedure for replacing the filter-drier following industry standards.
➡️ Proper manipulation of the service valve is critical, requiring depressurizing the gland packing/stuffing box (pressostat d'étanchéité) before adjusting the stem/square drive.
➡️ Accurate pressure readings (HP/LP) are only possible when the service valve is in the reading position, where the pintle allows flow to the gauge connection port.

📸 Video summarized with SummaryTube.com on Dec 04, 2025, 19:44 UTC