Abstract: A fast and flexible pressure testing apparatus includes two parallel pressure channels having independent pumps and pressure regulators. Pressure pulse cycle times are minimized by using large diameter hydraulic lines. A fluid accumulator in each channel stores pre-pressurized fluid to avoid pressure delivery delays due to limited pump output. In embodiments, the outputs of the two delivery channels can be combined to deliver pressure pulses to the part under test (PUT) from either channel in any desired sequence, or one channel can be used to return the PUT to its initial status. Embodiments gate the pressure pulses using servo valves, which can have pressure outputs that are proportional to their control signals, thereby enabling shaped output pressure profiles according to shaping of the control signals. The pressure channels can be further split into first and second branches which set the ranges over which the channel output can be varied.

Abstract: A modular ladder includes interconnectable segments that have utility conduit sections fixed thereto. The conduit sections interconnect to form a utility conduit when the ladder is assembled, thereby allowing safe use of a utility at any ladder height, without the inherent risks and inconvenience of providing a separate conduit. The conduit sections are separated when the ladder is disassembled, thereby saving time, effort, and storage space. In various embodiments, the modular ladder can be configured as any of a step ladder, single ladder, articulated ladder, combination ladder, extension ladder, fixed ladder, mobile ladder stand, and ladder stand platform, among others. Angle-adjusting accessories can enable assembly of the modular ladder in free-standing configurations. Addition of various accessories can provide casters, tilt stabilizers, and trays optimized for various tasks, thereby allowing a user to purchase accessories to expand the modular ladder's capabilities over time.