You may have noticed that FJC uses the term “backflow preventer” when describing our refrigerant dispensing tools—can taps, U-charge hoses and Hoses with gauge. You may have also noticed that our competitors might use the term when discussing R-134a tools, but not when discussing R-1234yf tools. That’s because our R-1234yf tools are patented with this ingenious safety device, and truth be told, the device is far more important for yf tools than R-134a tools.
Let me explain.
An integrated backflow preventer is a safety device located in the connector of a dispensing tool. The preventer may resemble a small ball bearing, and may or may not also include a spring. Essentially the device allows the flow of refrigerant in one direction only—away from the can and into the A/C
While charging an automotive A/C system, the can should be connected to the low side (low pressure) port with the dispensing tool. However, if a tech or home user accidentally connects to the high side (high pressure) port using a tool WITHOUT a backflow preventer a dangerous situation would occur. The high pressure from the port could cause the refrigerant to flow backwards into the can with great force, causing it to explode. Believe it or not, this is not an uncommon occurrence. This situation becomes all the more dangerous with R-1234yf as it is classified as mildly flammable, and mixing an explosion with a flammable liquid or gas exacerbates the severity of the impact of the explosion and increases the chance of serious injury.
So, to be safe when using R-1234yf, always use an FJC dispensing device to safely add the refrigerant to your automobile A/C