What does the 195 in 4B195 denote?

What does the 195 in 4B195 denote?

• A. The normal operating pressure is 195 psi
• B. The hydrostatic test pressure is 195 psi
• C. The temperature rating is 195 degrees
• D. The model number is 195

Answer: (A)

The number after the class designation shows the cylinder’s operating pressure in psi. Here, 195 means the extinguisher is designed to operate at 195 psi when charged and ready for use. The hydrostatic test pressure is a separate, higher specification used during testing to prove the cylinder can withstand pressure, and would be listed elsewhere. A temperature rating would be shown as a temperature value, not a pressure, and a model number would be a different identifier. So the 195 denotes the normal operating pressure of the cylinder in psi.

The number after the class designation shows the cylinder’s operating pressure in psi. Here, 195 means the extinguisher is designed to operate at 195 psi when charged and ready for use. The hydrostatic test pressure is a separate, higher specification used during testing to prove the cylinder can withstand pressure, and would be listed elsewhere. A temperature rating would be shown as a temperature value, not a pressure, and a model number would be a different identifier. So the 195 denotes the normal operating pressure of the cylinder in psi.