Which statement about fittings in clean agent systems is correct?

Which statement about fittings in clean agent systems is correct?

• A. Cast-iron fittings and Class 150 fittings are not permitted.
• B. Cast-iron fittings and Class 150 fittings are permitted.
• C. Cast-iron fittings are permitted, but Class 150 fittings are not.
• D. Only Class 150 fittings are permitted, not cast-iron.

Answer: (A)

Fittings in clean agent systems must be compatible with the agent and rated for the system’s operating pressure. Cast-iron fittings are typically not permitted because halogenated clean agents can be corrosive to iron and its porosity can harbor moisture, leading to leaks and contamination. Class 150 fittings are designed for lower-pressure service and may not withstand the higher pressures used to distribute clean agents; their seal materials and flanges may also be incompatible with the agent. For these reasons, both cast-iron and Class 150-rated fittings do not meet the requirements for clean agent piping. Approved options are fittings made from materials like stainless steel, carbon steel, or copper, with flange and gasket ratings appropriate to the system’s pressure and the agent’s compatibility.

Fittings in clean agent systems must be compatible with the agent and rated for the system’s operating pressure. Cast-iron fittings are typically not permitted because halogenated clean agents can be corrosive to iron and its porosity can harbor moisture, leading to leaks and contamination. Class 150 fittings are designed for lower-pressure service and may not withstand the higher pressures used to distribute clean agents; their seal materials and flanges may also be incompatible with the agent. For these reasons, both cast-iron and Class 150-rated fittings do not meet the requirements for clean agent piping. Approved options are fittings made from materials like stainless steel, carbon steel, or copper, with flange and gasket ratings appropriate to the system’s pressure and the agent’s compatibility.