Abstract: A self-supporting system for positioning and restraining the U-bend tubes in the U-bend region of a nuclear steam generator includes arrays incorporating unique support bars having nubs projecting in the out-of-plane direction of the tube planes. The system also includes assemblies for spacing the arrays, tie bars to prevent the arrays from splaying and saddle bar assemblies to support the outermost tube layers. The system provides positive restraint to nub engaged tubes in both the in-plane direction of the tube planes and the out-of-plane direction.

Abstract: A self-supporting system for positioning and restraining the U-bend tubes in the U-bend region of a nuclear steam generator includes arrays incorporating unique support bars having nubs projecting in the out-of-plane direction of the tube planes. The system also includes assemblies for spacing the arrays, tie bars to prevent the arrays from splaying and saddle bar assemblies to support the outermost tube layers. The system provides positive restraint to nub engaged tubes in both the in-plane direction of the tube planes and the out-of-plane direction.

Abstract: A self-supporting system for positioning and restraining the U-bend tubes in the U-bend region of a nuclear steam generator includes arrays incorporating unique support bars having nubs projecting in the out-of-plane direction of the tube planes. The system also includes assemblies for spacing the arrays, tie bars to prevent the arrays from splaying and saddle bar assemblies to support the outermost tube layers. The system provides positive restraint to nub engaged tubes in both the in-plane direction of the tube planes and the out-of-plane direction.

Abstract: A self-supporting system for positioning and restraining the U-bend tubes in the U-bend region of a nuclear steam generator includes arrays incorporating unique support bars having nubs projecting in the out-of-plane direction of the tube planes. The system also includes assemblies for spacing the arrays, tie bars to prevent the arrays from splaying and saddle bar assemblies to support the outermost tube layers. The system provides positive restraint to nub engaged tubes in both the in-plane direction of the tube planes and the out-of-plane direction.

Abstract: A support bar for tubes in a heat exchanger, such as the U-bend tubes in the U-bend region of a recirculating, nuclear steam generator, provides positive restraint in both the in-plane direction of the tube planes and the out-of-plane direction. The bar has pairs of parallel surfaces aligned with first and second axes such that the bar may be positioned with either axis arranged parallel to the tube planes. The bar can be used in place of other types of tube support bars, and can also be used as an auxiliary bar for installation into a fully assembled heat exchanger to provide additional support to supplement other tube support arrangements.

Abstract: A support bar for tubes in a heat exchanger, such as the U-bend tubes in the U-bend region of a recirculating, nuclear steam generator, provides positive restraint in both the in-plane direction of the tube planes and the out-of-plane direction. The bar has pairs of parallel surfaces aligned with first and second axes such that the bar may be positioned with either axis arranged parallel to the tube planes. The bar can be used in place of other types of tube support bars, and can also be used as an auxiliary bar for installation into a fully assembled heat exchanger to provide additional support to supplement other tube support arrangements.

Abstract: A lattice high bar for a nuclear steam generator tube support bar array has scalloped indentations along its length. The scalloped indentations are located at points on the high bar where water tubes will contact the high bar. The indentations extend from one edge of the high bar to about two-thirds of the distance across the bar. When the high bars are used in a lattice bar array, only the unscalloped portion of the high bar contacts an adjacent supported tube, thereby reducing the contact area and the likelihood of corrosion and cracking and also reducing the length over which inspection is impeded. Additionally, the flow path created by opposed but overlapping scallops at the 120° intersections at certain points along the high bars improves the flow sweeping over the surface of the supported tube.

Abstract: A one-piece curved floating primary divider plate (40) is described which is suitable for retrofit in an existing steam generator. The one-piece curved floating primary divider plate eliminates most loose parts and reduces leakage of the primary flow resulting in an improvement in the thermal performance of a steam generator. A method of retrofitting a primary divider plate in an existing steam generators is also described to improve the thermal performance of the steam generator.

Abstract: A one-piece curved floating primary divider plate (40) is described which is suitable for retrofit in an existing steam generator. The one-piece curved floating primary divider plate eliminates most loose parts and reduces leakage of the primary flow resulting in an improvement in the thermal performance of a steam generator. A method of retrofitting a primary divider plate in an existing steam generators is also described to improve the thermal performance of the steam generator.

Abstract: An improved articulated sludge lance with a retractable movable extension nozzle for cleaning a steam generator. The extension nozzle includes a flexible conduit adapted to be moved with a wire cable to place the nozzle in close proximity to a support plate for effectively cleaning the broached holes therein. A bumper member fastened to the flexible conduit provides a side-to-side motion from impact with the tubes when the lance is moved therethrough.

Abstract: An articulated lance for cleaning sludge located between steam generator tubes is disclosed. A plurality of radius blocks are attached to the end of manipulator member and are actuatable by a cam assembly to form an arc permitting the lance to be received between adjacent tubes within a tube bundle. A plurality of fluid passageways interconnect a fluid inlet on the manipulator member with one or more outlet orifices adjacent the end of the lance. The outlet orifices are positioned outwardly with respect to the end of the manipulator member so that fluid passing therethrough can be directed to impinge upon sludge surrounding the tubes. A spring backing place biases the radius blocks and the manipulator member back into the same plane upon deactuation of the cam assembly.

Abstract: Warning lights at a railroad grade crossing are energized at a predetermined flash rate when a train is approaching through the use of an essentially fail-safe solid state crossing controller employing circuitry that is active in creating an off condition of the warning lamps. A controller unit operates a pair of warning lamps alternately in synchronism with a warning rate (flash rate) signal having a predetermined repetition rate, such as 55 pulses per minute. When the crossing is safe, an RC circuit in the lamp driver responds to a 500 Hz safe status signal by providing continuous control excitation to a normally conductive lamp switching circuit to maintain the lamps deenergized. In a failure mode, the normal condition of the switching circuit maintains one lamp of each pair continuously energized.