What size corrugated stainless tubing gas pipe should be left with the regulator for a system with a total connected load of 326,000 btu/hr and a design pressure drop of 0.5 in. w.c.?

• A. EHD 20
• B. EHD 25
• C. EHD 30
• D. EHD 37

Answer: (D)

The correct choice regarding the size of corrugated stainless tubing gas pipe to be left with the regulator for a system exhibiting a total connected load of 326,000 Btu/hr and a design pressure drop of 0.5 inches water column (w.c.) is based on the specifications and calculations related to gas flow and pressure requirements.

For a system with a significant connected load like 326,000 Btu/hr, it is essential to ensure that the gas pipe size can handle that flow efficiently while maintaining the acceptable pressure drop specified in the design. Corrugated stainless tubing (CST) is chosen for its flexibility and ease of installation while also having the capability to transport gas effectively.

When considering the pressure drop of 0.5 inches w.c. across the length of the tubing, the larger diameter options become more favorable, as they can deliver the required volume of gas with a minimal pressure drop.

Choosing EHD 37 allows for a larger flow capacity, ensuring that the system operates efficiently without creating undue strain on the regulator due to insufficient gas supply. The EHD 37 size provides an optimal balance, accommodating the load while adhering to the design specifications, thereby maintaining operational integrity.

In summary, EHD 37 is the appropriate size