What should be the design pressure for non-metallic hoses used indoors?

The design pressure for non-metallic hoses used indoors is established to ensure that the hoses can safely handle the pressures they will be exposed to during regular use. A design pressure of 350 psi provides a suitable safety margin for typical indoor applications involving gas or fuel lines, which reduces the risk of failure or leaks under normal operating conditions. This specification aligns with safety standards required for handling LPG or CNG in engine fuel systems, contributing to safe operational practices.

In contrast, lower pressure ratings, like 150 psi and 250 psi, may not provide adequate performance and safety for high-demand applications, while the higher rating of 450 psi would likely be unnecessary for typical indoor environments and could lead to increased costs and complexity in material selection. Therefore, choosing 350 psi strikes an appropriate balance between safety and practicality for non-metallic hoses in indoor settings.