Sunshine tests one of the new, more difficult Chinese hot water bottles. After first trying to inflate it without a mouthpiece, she quickly decides that she prefers the safety of the mouthpiece, hose, and check valve. What's more, she wants to use our new two-channel pressure recording device to measure the pressure on both sides of the check valve, to see whether it adds any greater pressure requirement. In spite of a near-constant air leak, she manages to blow it to bursting with nothing but lung power!

Sunshine tests one of the new, more difficult Chinese hot water bottles. After first trying to inflate it without a mouthpiece, she quickly decides that she prefers the safety of the mouthpiece, hose, and check valve. What's more, she wants to use our new two-channel pressure recording device to measure the pressure on both sides of the check valve, to see whether it adds any greater pressure requirement. In spite of a near-constant air leak, she manages to blow it to bursting with nothing but lung power!