For a new low pressure boiler using undiluted propane gas, which size corrugated stainless steel tubing should be used to supply 820,000 BTU of gas per hour?

To determine the appropriate size of corrugated stainless steel tubing (CSST) for supplying 820,000 BTU per hour of gas, it is essential to consider the capacity of the tubing in relation to the gas flow requirements specified. In this scenario, using a low-pressure boiler with undiluted propane gas, the correct size of the CSST must effectively accommodate the volume of gas required to support the rated input.

The sizing chart or tables for CSST generally provide maximum gas flow capacities for different sizes. The critical factor is that the selected tubing must sufficiently deliver the necessary BTU input without causing excessive pressure drop or insufficient flow, which could hinder the effective operation of the boiler.

The selected size of 60 EHD CSST aligns with the requirement of 820,000 BTU per hour based on standard practices and industry guidelines. This size is designed to handle high BTU loads and ensures that the gas supply maintains adequate pressure and flow rate. Sizing larger than the actual need could lead to unnecessary costs and complexity, while under-sizing could cause operational inefficiencies or hazards.

In contrast, the other sizes listed may either be too small to adequately supply the required gas volume for the boiler’s operation or exceed the necessity, leading to potential mis