Abstract: A construction for inflatable rafts and the like wherein two inflatable tubes are joined together approximately at right angles, the end of the first tube being joined to the side of the second tube. Both tubes are maintained integral in themselves except for small pierced openings to permit the passage of inflating gas between them. The method of fabricating the construction includes partially forming a first tube from a flat strip of fabric and providing a folded length of seam tape, the outer surfaces of which are joined to the inside of the first formed tube at the end margin thereof. The folded seam tape thus seals the end of the first tube. The sealed end of the first tube is then cemented to a length of fabric which will form the second tube. The area of cementing the two tubes is over a portion of the second tube which is the normal area of incidence of the two tubes as they intersect.

Abstract: A pressure relief valve including a sleeve having means to be suitably attached to the walls of a container, the end of the sleeve remote from the wall carrying an annular shaped sealing edge cooperating with a spherically shaped piston resiliently urged toward the sealing edge by means of a conically shaped volute spring.