For a low pressure boiler using undiluted propane gas and located 156 feet away from the gas meter, which size corrugated stainless steel tubing should be used to supply an 820,000 BTU of gas per hour boiler?

In this scenario, the proper selection of corrugated stainless steel tubing (CSST) size is critical for ensuring that the low-pressure boiler receives adequate gas supply for optimal performance. The boiler's requirement of 820,000 BTU per hour and the distance of 156 feet from the gas meter are key factors in determining the correct tubing size.

The correct choice of 60 EHD (Extra Heavy Duty) shows that this size is capable of handling the specified BTU demand at the distance from the gas source without experiencing excessive pressure drop. Propane has specific characteristics, including its flow rate and pressure requirements, which must be taken into account. CSST sizing tables provide guidance on the amount of gas that can be delivered through various sizes of tubing over certain distances, factoring in the type of gas being used.

Selecting a CSST size that is too small might lead to insufficient gas flow, which could result in the boiler not operating efficiently or failing to ignite due to low gas pressure. Conversely, using a size that is too large could be wasteful in terms of material costs and installation complexity.

In this case, the 60 EHD size balances the requirement of delivering 820,000 BTUs at a distance of 156 feet while adhering to