I have a hand vacuum pump I'm using to evacuate air out of a container and hold the vacuum for a long period of time. This pump came with a valve that eventually failed. I bought a few more just like it and those failed as well. I guess the diaphragm inside the valve is too weak to hold a vacuum for extended periods of time. I think this hand vacuum pump is for pools or something. I'd get a stronger hand pump or stronger valve, but I'm not sure what kind of company would be in that business. I don't necessarily have to get just a stronger valve. I'll buy a new hand pump if I need to. But does anyone know if there's a manual pump that won't fail from having a decent vacuum for extended periods of time? Thanks.