The relief valve for a low pressure hot water system should be set at:

In a low pressure hot water system, the relief valve is a critical safety component designed to prevent excessive pressure buildup, which could lead to potential system failures or hazardous situations. The typical setting for the relief valve in such systems is established at 30 PSIG.

This pressure setting is considered standard for many low pressure hot water applications, as it balances safety and operational efficiency. A relief valve operates by opening to release pressure when it exceeds the set limit, thus protecting the system from damage due to overpressure.

Setting the relief valve at 30 PSIG ensures that it activates only at pressures that could be dangerously high for the system while still allowing for adequate pressure for system operation during normal functioning. By having it set at this level, the risk of the valve frequently opening and closing due to normal pressure fluctuations is minimized, ensuring reliability and longevity of the valve.

Overall, 30 PSIG is optimal for maintaining safe and effective operation in low pressure hot water systems, adhering to industry standards and safety regulations.