3.5.1 — Service & Access
Service and access valves make installation, commissioning, troubleshooting, and recovery possible. Good service design reduces leaks by minimizing unnecessary joints while still providing the access needed to measure and control the system responsibly.
Service Valves and Access Ports
Service valves (including compressor service valves) allow isolation and controlled access to system sections. Access ports (Schrader-type or coreless) allow gauges, sensors, and recovery hoses to connect — they also add leak potential, so use caps with seals and verify tightness after every connection.
Hose Connection Best Practices
- Purge air from hoses before connecting to the system to reduce the risk of introducing non-condensables.
- Verify that rated hose and manifold pressures match the expected system pressure ranges (kPa and psig) before connecting to high-pressure ports.
- Replace access port caps with sealing caps after each service connection — core leaks are a common source of refrigerant loss over time.
Hand Valves (Isolation)
Hand valves isolate components such as filter-driers, solenoids, or receivers for service. Valves should be operated fully open or fully closed unless they are specifically designed for throttling — a half-open globe valve causes seat erosion and unstable control.
Use proper stem packing practices and do not overtighten packing nuts — over-tightening damages packing and creates persistent leaks. If a valve stem seeps after service, replace the packing before the next call becomes an emergency.