How does the tiny rubber ring around a water resistant phone’s SIM tray hold back all the water? If you pinch or sit on it, is it broken?

Question

I get how the charge port and buttons are protected, you can’t remove them. But when you change the SIM, there’s just a small strip of soft gooey material near the top of the tray. It looks like it can’t possibly protect against the force of dunking the entire thing underwater. Is it the weakest part of the waterproofing, does it wear out?

In: Technology

Answer 1

I haven’t looked at the SIM tray, but seals work by using the force of the liquid pushing them into their seats to increase their ability to cover the opening. Most seals will still work even with some damage, but will often fail if the either of the surfaces they come in contact with are warped or cracked. Pinching or sitting on the seal itself should have no effect.