What is the maximum pressure increase allowed during an accumulation test for high-pressure boilers?

The maximum pressure increase allowed during an accumulation test for high-pressure boilers is 6% above the Maximum Allowable Working Pressure (MAWP). This is established to ensure safety while assessing the boiler's ability to handle pressure fluctuations without failing.

During an accumulation test, the pressure within the boiler is increased to this specified limit to evaluate its operational integrity and to ensure that all safety devices function as intended under extreme conditions. If the boiler can withstand this pressure without any signs of distress or failure, it confirms that the design and materials are adequate for service conditions.

Allowing up to 6% above the MAWP helps to balance safety margins with realistic operational parameters, reflecting industry standards and code requirements. Therefore, a threshold beyond this, such as 10% or higher, could pose risks of failure or damage to the boiler structure or components, making 6% the appropriate standard for such tests.