摘要:
A high strength bolt fastens a baffle plate and a former plate of a pressurized water nuclear reactor pressure vessel together. The bolt has a head portion and an integral locking member extending from the head portion for engaging one of the structural members to lock the bolt with the structural member. The integral locking member portion has a lower yield stress than the yield stress of the shank. A lower yield stress may be obtained by selective annealing. The locking member is less susceptible to stress corrosion cracking in high temperature, high pressure water of commercial nuclear power reactors.
摘要:
A shock absorber system was designed to absorb the energy imparted to doors in a nuclear reactor ice condenser compartment as they swing rapidly to an open position. Each shock absorber which is installed on a wall adjacent each door is large and must absorb up to about 40,000 foot pounds of energy. The basic shock absorber component comprises foam enclosed in a synthetic fabric bag having a volume about twice the foam volume. A stainless steel knitted mesh bag of the same volume as the fabric bag, contains the fabric bag and its enclosed foam. To protect the foam and bags during construction activities at the reactor site and from the shearing action of the doors, a protective sheet metal cover is installed over the shock absorber ends and the surface to be contacted by the moving door. With the above shock absorber mounted on a wall behind each door, as the door is forcibly opened by steam pressure and air resulting from a pipe break in the reactor compartment, it swings at a high velocity into contact with the shock absorber, crushes the foam and forces it into the fabric bag excess material thus containing the foam fragmented particles, and minimizes build-up of pressure in the bag as a result of the applied compressive force.
摘要:
A nondestructive method for determining the amount of deformation induced in a material by a compressive force is provided that includes the steps of uniformly dispersing a quantity of a particulate tagging substance in the material whose presence and distribution is detectable by a form of radiant energy, applying a compressive to the material, and then determining the extent to which the material is compressively deformed by transmitting the appropriate radiant energy through the material to determine changes in the density and distribution of the particulate tagging substance. The method may advantageously be applied to determine the extent to which a granular material such as asphalt concrete has been compacted over a roadbed, as well as to determine strain and wear patterns in gaskets formed from elastic materials.
摘要:
A nondestructive method for determining the thickness of a non-electrically conductive material is provided that comprises the steps of uniformly dispersing a quantity of a ferromagnetic particulate tagging substance in the material whose presence and distribution is detectable by a form of radiant energy, such as the high-frequency electromagnetic field emanated from an eddy current probe, and then calibrating the output of the eddy current probe with a sample material having a known thickness that has been tagged with the same tagging substance at the same density. The thickness of the material is then determined by comparing the amplitude of electromagnetic coupling with the material with that obtained with the sample. The method may advantageously be applied to determine the thickness of a granular material such as asphalt concrete over a roadbed, as well as the strain and wear patterns in gaskets formed from elastic materials.
摘要:
Shock absorbing missile launch pad for Mx type missiles having molded ethylene propylene diene terpolymer composition. Pad has curved resilient rubber pad with a Teflon-fiberglass laminate bonded to outer convex surface thereof, and has a support plate bonded to the inner concave surface thereof. Springs are provided to urge pad away from missile at launch to prevent damage to missile.
摘要:
An elastomeric seal for sealing a large annular space having a groove on the low pressure side so that the seal will deflect easily when inserting a cylinder from the low pressure side and will withstand high differential pressure without blowing through.
摘要:
A method and apparatus for approximating the life of a gasket used in a predetermined environment is provided which allows for the long-term exposure to the environment to be simulated over a shortened period of time. The method and apparatus utilize the steps of placing a gasket sample in a test assembly, clamping the gasket sample within the test assembly at a predetermined clamping pressure whereby a chamber is formed within the interior of the gasket sample, filling the chamber with a gas at a predetermined pressure from a gas fill system, changing the temperature of the gasket sample over a predetermined number of temperature cycles, and measuring the amount of the gas which leaks from the chamber. The apparatus may also include a pressure control system for changing the pressure within the chamber over a predetermined number of pressure cycles or in response to predetermined temperature conditions.
摘要:
A resilient, strong, high modulus polyurethane elastomer structural member is made from (A) a prepolymer prepared from a composition consisting essentially of 4,4'-diphenylmethane diisocyanate, low molecular weight triol, and polyoxytetramethylene glycol, and (B) hydroquinone di-(.beta.-hydroxyethyl) ether, as a chain extender.
摘要:
A novel seal is provided for sealing the annular gap between a tube and a cylinder, such as between a missile and its launch canister, which comprises an annular base for engaging the outer surface of the missile, an annular flap formed integral with the base and extending radially outwardly and downwardly to seal the annular gap between missile and canister, the annular flap having formed thereon means to control the location of buckling around the periphery thereof upon compression of the seal within the gap. The means to control the buckling of the flap include, in one representative embodiment, a plurality of prebuckling webs or, in an alternative embodiment, a plurality of slit pairs regularly spaced around the circumference of the flap, to promote buckling of the seal at predetermined locations.