Abstract: A receptacle made of air-impervious sheet material which is heat-sealable at least on one face thereof. The receptacle has portions with the heat-sealable face of one portion opposed to the heat-sealable face of another. The portions are heat-sealed together forming a seal for the receptacle. The receptacle has a check valve for venting air therefrom for deflation of the receptacle while checking ingress of outside air. The check valve comprises an elongate flat tube of heat-sealable sheet material extending between the portions of the receptacle through the seal from the inside to the outside of the receptacle. The tube has opposed walls with an elongate longitudinal passage between them from one end of the tube to the other. The opposed portions of the receptacle are heat-sealed to the outside of the tube in line with the seal.

Abstract: A balloon comprising first and second balloon sheets and a self-sealing valve positioned between the balloon sheets. Each balloon sheet has a body portion and a stem portion extending outwardly from the body portion and terminating at a stem end. The balloon sheets are bonded together generally around their peripheries to define a balloon body and balloon stem. The stem portion of the first balloon sheet is shorter than the stem portion of the second balloon sheet so that the stem end of the second balloon sheet extends beyond the stem end of the first balloon sheet to define an extended portion of the second balloon sheet. The valve comprises first and second valve sheets each having an inlet end, an outlet end, and an intermediate region between the inlet and outlet ends. The inlet end of the second valve sheet extends outwardly beyond the inlet end of the first valve sheet to define an extended portion of the second valve sheet.