When the maximum allowable working pressure exceeds 100 psig, what is required for blowoff piping materials?

When the maximum allowable working pressure exceeds 100 psig, blowoff piping materials must be at least XH (extra heavy) thickness and not galvanized. This requirement is crucial because at higher pressures, the integrity and strength of the piping material become essential for safety and functionality.

Using XH thickness ensures that the piping can handle the increased pressure without the risk of failure, such as rupturing or leaking. Galvanization, while useful for corrosion resistance, may not be suitable in high-pressure applications because it can affect the mechanical properties and reduce the overall strength of the piping. Therefore, the specification explicitly states that non-galvanized materials are preferable in these scenarios. This combination of thickness and material type helps ensure the safety and effectiveness of the blowoff piping.