Abstract: The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered.

Abstract: A shock suppressing device adapted to be attached to the aft end of a shoulder fired rocket launcher. The device comprises an elongated, flexible, tubular member formed of a compressible, permeable fabric. The member has an expanded diameter substantially greater than the diameter of the exhaust opening in the aft end of the rocket launcher tube. In one embodiment, the rear of the member is covered with fabric so that the member forms a bag covering the exhaust opening of the rocket launcher. The member has a sufficient expanded volume to contain the exhaust gases generated by a launched rocket thereby confining these exhaust gasses and their associated flash, smoke and blast wave. The blast wave is dissipating by forcing it to penetrate the member. In another embodiment, the rear of the member is open thus causing the generated shock wave to be accelerated rearwardly while being dissipated. The full expansion of the shock wave is not allowed until the shock wave has been reduced significantly.