The one-way valves we use for most of our hot water bottle investigations are an essential safety device. But when our models try to blow the more difficult hot water bottles, which we know are able to inflate at pressures well below the maximum pressure capability of our technician's lungs, there must be a cause. In this clip, Summer will blow up a Chinese hot water bottle part-way, and record the pressure seen by the hot water bottle. She then mashes the vent pedal to let the air out, and we move the pressure sensor to a tapoff located before the one-way valve, so we can see the pressure ...

The one-way valves we use for most of our hot water bottle investigations are an essential safety device. But when our models try to blow the more difficult hot water bottles, which we know are able to inflate at pressures well below the maximum pressure capability of our technician's lungs, there must be a cause. In this clip, Summer will blow up a Chinese hot water bottle part-way, and record the pressure seen by the hot water bottle. She then mashes the vent pedal to let the air out, and we move the pressure sensor to a tapoff located before the one-way valve, so we can see the pressure she must exert to open the valve.