| Feature | 70-2006 | 70-2020 (Updated) | | :--- | :--- | :--- | | | HCFCs, HFCs, NH3 (Ammonia) | Added A2L (mildly flammable) and A3 (highly flammable) refrigerants like R-32, R-454B, and propane (R-290). | | Test Uncertainty | +/- 5% allowed | +/- 3% for critical flow; added rigorous uncertainty analysis protocol. | | Instrument Calibration | Annual calibration suggested | Mandatory traceable calibration to NIST every 6 months. | | Backpressure Correction | Simplified method | New complex correction factors for valves with built-in backpressure compensation. | | Reporting | Basic data sheet | Mandatory electronic data logging with a minimum 1 second sampling rate. |
Introduction: The Quest for the Right Standard ashrae standard 702006 pdf updated
This article will clarify the status of ASHRAE Standard 70-2006, explain what it actually covers, and guide you on how to obtain the correct, legal version of this standard. We will explore why the 2006 edition remains historically relevant, what superseded it, and how to ensure your facility is compliant with the latest safety codes. Part 1: What is ASHRAE Standard 70? Before hunting for a PDF, it is critical to understand what the document is . ANSI/ASHRAE Standard 70 , officially titled "Method of Testing for the Discharge Capacity of Pressure Relief Valves for Ammonia and Halocarbon Refrigerants," is a benchmark document for the refrigeration industry. The Purpose of the Standard Unlike general safety codes (like ASME Boiler and Pressure Vessel Code), ASHRAE 70 provides a uniform, reproducible laboratory method for testing the relieving capacity of pressure relief valves (PRVs). These valves are the last line of defense in a refrigeration system; if the pressure vessel overheats or malfunctions, the PRV must open and vent enough refrigerant to prevent a catastrophic explosion. | Feature | 70-2006 | 70-2020 (Updated) |