Pressure rise rate test method for vacuum furnace

The pressure rise rate test of a vacuum furnace is primarily used to evaluate the furnace's sealing performance and is a crucial method for determining whether a vacuum system exhibits leaks or venting. Before testing, the vacuum furnace must be evacuated to the specified working vacuum level and maintained in stable operation for a period to allow the internal pressure to reach equilibrium. The formal test typically begins after all vacuum pump valves are closed.

During the test, the pressure changes within the furnace are recorded over a specific time period. Pressure is generally monitored continuously using a vacuum gauge, and the "pressure rise per unit time" is used as the pressure rise rate indicator, commonly expressed in Pa/h or Pa/min. A rapid pressure rise usually indicates a leak or significant material venting; a slow and stable change indicates good sealing performance.

After the test, the pressure rise rate needs to be evaluated in accordance with equipment standards. Industrial vacuum furnaces typically require a low pressure rise rate to ensure long-term stable operation; for example, high-vacuum equipment generally requires a low rate (e.g., ≤0.5 Pa/h or lower, depending on process requirements). If the test results are not up to standard, the flange seals, welds, valves and sealing rings should be checked and repaired point by point.