The valve that  prevents backflow of blood from right ventricle to right auricle.

The valve that prevents backflow of blood from the right ventricle to the right auricle is the tricuspid valve. Here are the steps of how it works:

1. Blood flows into the right atrium from the superior and inferior vena cava.
2. The blood then moves from the right atrium into the right ventricle through the tricuspid valve, which opens to allow this flow.
3. When the right ventricle contracts to pump the blood out to the lungs, the tricuspid valve closes to prevent the blood from flowing back into the right atrium.
4. The blood is then sent to the lungs where it is oxygenated, and the process begins again.

So, the tricuspid valve is the one that prevents the backflow of blood from the right ventricle to the right atrium (auricle).