What working pressure is required for steel fittings in an LP gas system that will operate at 30 psi?

In an LP gas system that operates at 30 psi, the working pressure required for steel fittings is determined by safety regulations and the potential for surge pressures within the system. Steel fittings must be able to handle pressures significantly above the maximum operating pressure to ensure safety and prevent potential failures.

Typically, the working pressure rating for fittings is set well above the operating pressure to account for pressure fluctuations and safety factors. For an LP gas system that operates at 30 psi, fittings are usually required to withstand a minimum working pressure that exceeds the operating pressure by a safe margin, which is often standardized in relevant codes.

The choice of 128 psi reflects this safety requirement, being above the maximum operating pressure while providing a sufficient margin for unexpected increases in pressure. Fittings rated lower than this could potentially fail under surge conditions, leading to hazardous situations. Moreover, standards often dictate that fittings on a system must be rated for higher than the operational pressures to minimize risks associated with gas leaks or ruptures.

Thus, recognizing the need for robust fittings capable of handling significantly higher pressures than the system operates at underscores why 128 psi is the correct working pressure rating in this context.