Hi there, excuse my ignorance but I have recently purchased a 12ft avon inflatable (hypalon) and was wondering whether it is possible to over inflate it. My friend has a similar military avon inflatable and his has pressure release valves fitted on his so I was wondering if I may need something similar to this or some sort of pressure measuring device so I can stop it exceeding the recommended psi (Does anyone know what the psi is?). Any suggestions are most welcome. Many thanks Murphoir....