At what psi should low pressure accessory hoses used on a wheeled extinguisher be tested?

Low pressure accessory hoses used on a wheeled extinguisher should be tested at 300 psi to ensure their integrity and safety during operation. This testing pressure is established to verify that the hoses can withstand the pressures they might encounter in actual use, ensuring they do not fail or leak when the extinguisher is deployed.

The choice of 300 psi is significant because it reflects a standard that balances safety and functionality. Testing at this pressure helps to identify any potential weaknesses in the hoses that may not be apparent under normal operating conditions. It ensures that the hoses can handle the pressures during discharge without compromising the effectiveness of the extinguisher.

Choosing lower pressures would not adequately test the durability of the hoses, potentially leading to failures during an emergency situation. The selection of 400 psi, while higher, may exceed what is necessary for operational performance, posing unnecessary risks during testing and potentially damaging the hoses. Hence, 300 psi provides an appropriate and effective testing standard for low pressure accessory hoses on wheeled extinguishers.