What is the maximum pressure loss allowed between the termination of the utility installation and an appliance for a piping system with supply pressure exceeding 14" W.C.?

The maximum pressure loss allowed between the termination of the utility installation and an appliance is determined by standards related to gas piping systems. For systems where the supply pressure exceeds 14" W.C., a maximum pressure loss of 1.0" W.C. (equivalent to 0.250 kPa) is specified. This value ensures that the appliance receives sufficient pressure to operate safely and efficiently.

The rationale behind this maximum pressure loss is to maintain functional performance and safety for the appliance. If the pressure drop were to exceed this level, there could be insufficient gas pressure at the appliance, leading to improper combustion, reduced efficiency, and potential safety hazards.

In contrast, other values listed either represent pressures that are too low and may not provide adequate performance (like 0.25" W.C. or 0.375 kPa) or pressures that exceed what is generally permissible (like 2.0" W.C.). Therefore, the choice of 1.0" W.C. aligns with industry standards aimed at maintaining operational integrity of gas appliances under high supply pressures.