Fast seal

grabcad

Here, I propose a sliding lock mechanism for sealing and locking, fixed by a wedge. It is fast and easy to use; only two sliding bars are required in the brick, which can be placed into the cavity after pumping out air. The lock is then secured with the insertion of a wedge into the cavity. However, certain challenges exist such as the long rectangular cavity form, plastic material deformation, and changing load directions. To solve these issues, I have designed an evenly load-distributed locking mechanism along the cavity and selected a plastic material with high elasticity modulus. Additionally, a seal suitable for working under varying load directions has been chosen. The sliding lock between the brick and cavity is fixed by a wedge, while the Parker four-corner spliced gasket made from Nitril (N7021, Durometer 60) with hollow-o profile B015 and friction fit installation serves as the seal. The pressure difference of 3 bar is applied to the cavity surface of 17564mm². This results in a total force of 5269N acting on the brick-cavity connection, with an additional 1226N from the seal preload of 20 pound/inch on a 42.3-inch seal length. The required seal preload force is achieved by pumping air from the cavity. The seal diameter is 3.52mm, with a maximum compression of 28% (0.99mm) and a minimum compression of 20% (0.3mm) to allow for tolerances and cavity + block deformations under loads. The cavity material chosen is DuPont Performance Polymers Rynite® 540SUV BK544 Polyethylene Terephthalate (PET), a 40% glass-filled polymer with a tensile modulus of 13.5 GPa and tensile strength of 162 MPa. FEA calculations show that with the maximum applied load, the cavity deformation in the Z direction is 35 microns, providing a safety factor of 2 for equivalent stress. The tensile strength estimate reveals a tensile stress of 3.7 MPa in the Z direction, which is comparable to the equivalent stress regions with minimal flexural stress. The rough deformation estimate without considering flexural deformation is approximately 3 microns between the point of contact and the seal gland, closely aligning with FEA deformation regions.