The Jumbo Balloon has a one-way emergency screw valve inside, make sure it is screwed down very tight. On the opposite end of the tube make sure it is securely fastened into the black port coming out of the balloon. Do not forget to install the Pinch Clamp once inflated. Light Poles of the Jumbo Balloon must be free of burrs, etc. that could puncture your Jumbo Balloon, but the Jumbo Balloon has added material thick enough to prevent damage.
Also, once inflated, top off a little tighter a few hours later once material has expanded/stretched into place.