Abstract: A relief valve is configured to fit between the outlet of a hand pump and the inlet of an inflatable device to prevent the inflatable device from being inflated beyond a desired pressure. The relief valve can also be used to bleed excess air out of an inflatable device that is above its desired pressure.

Abstract: A hand pump for inflating rafts or similar inflatables has a first piston with a relatively low pumping volume which is capable of pumping relatively small volumes of air into a raft as the raft becomes full and is approaching its maximum pressure, and a second piston with a larger pumping volume that can pump larger volumes of air into a raft when it is empty or only partially filled. Both pistons are operated with a single plunger. When the plunger is rotated in a first direction to a first position a locking mechanism allows it to operate only the first piston, and when the plunger is rotated in a second direction to a second position the locking mechanism allows it to operate only the second piston.