Josie has been tasked with testing two different compact mouthpieces for blowing 260's and similar small entertainer balloons. The red one has been in use for a while at the Lab, and includes a tiny check valve, which contains a spring that gives it a "cracking pressure" of about 1 psi. While we do not believe this adds to the pressure required to inflate the balloon, the cross-sectional area of the opening and tube does seem to restrict airflow for fast blowers. So we built another one with no check valve and a slightly larger tube, which means that the user must manage the back pressure i...

Josie has been tasked with testing two different compact mouthpieces for blowing 260's and similar small entertainer balloons. The red one has been in use for a while at the Lab, and includes a tiny check valve, which contains a spring that gives it a "cracking pressure" of about 1 psi. While we do not believe this adds to the pressure required to inflate the balloon, the cross-sectional area of the opening and tube does seem to restrict airflow for fast blowers. So we built another one with no check valve and a slightly larger tube, which means that the user must manage the back pressure in the event they have to take a breath. Which will she prefer?