Abstract: An inertia stop by which excessive movement between two members may be prevented, includes a unit that may be fixed to one of the members and a further unit that includes a free component and a component that may be fixed to the other of the members, one component being in the form of an externally threaded shaft and the other component being in the form of an internally threaded block that is loosely rotatable on, relatively to, the shaft with the threads engaging so that the free component may rotate relatively to the other between a position in which it is dissociated from the first unit and a position in which is engages with the first unit so that further rotation in that direction is prevented.

Abstract: Three burners are supplied with pulverized fuel entrained in air from a splitter and are brought to combustion under optimum conditions by adjustment of the secondary air flow to each. The rates of flow of primary and secondary air are determined and signals from these, and a representation of the total fuel supply are supplied to a computer by which the amount of fuel flowing to each burner is deduced from the ratio of the air supplied to the burners.

Abstract: A boiler safety valve installation with a safety valve discharging relief steam through an upstand into a separately supported vent pipe. The upstand discharges through a belled nozzle approximately 30.degree. (0.5 steradian) included angle into the vent pipe thereby, on discharge of relief steam, inducing a sub-atmospheric pressure in the space intermediate the discharge nozzle and the vent pipe and lessening the risk of escape of steam at a sliding junction between the upstand and the vent pipe. In installation where the relief steam flow reaches supersonic velocity at discharge from the belled nozzle the vent pipe diameter is constricted by about 5%-10% at a zone downstream of the discharge nozzle to produce a shock front and reduce the velocity to sub-sonic, thereby reducing the frictional flow loss effects while economizing in vent pipe size without causing a build-up of back pressure in the space intermediate the discharge nozzle and the vent pipe.

Abstract: A tool head assembly for use in preparing a tube for welding including a center pilot which is rotatable. The center pilot is adapted to enter a bore of a tube to center the tool head assembly by being provided with ball bearings which rotate around the internal surface of the bore of the tube. In addition, the ball bearings are moveable thereby enabling a required operative diameter to be selected which enables the center pilot to enter the bores of a batch of tubes having a range of internal bores. The center pilot is engageable with a tool holder which is connectable to a machine tool. The tool holder also supports a pair of bevelling tools and a facing tool.

Abstract: A tube bending machine with rotary arms carrying a bending moment roller and a bending fulcrum roller has arm shafts mounted for axial movement. The arms are rotated for the tube bending action, whereby the bend so made in the tube lies in a predetermined non-planar arc. The arm shafts are turned by a pinion engaged by a rack and are moved axially by suitable pins engaged in cam slots with the rack and the cam slots all being moved simultaneously. In order to retain the tube in proper location or position during the trusts of non-planar arc bending there may be included more than one roller.

Abstract: A vapor generating and vapor superheating installation for marine propulsion purposes, and a method of operating such an installation. The installation including a vapor generating and vapor superheating unit adapted to be fired with fluent fuel including tubulous vapor generating and vapor superheating surface proportioned to give a predetermined superheated vapor output at a maximum firing rate. The installation also including a fluent fuel fired fluidized bed furnace provided with a superheater tube bank connected to receive vapor from the vapor generating and vapor superheating unit and arranged to impart superheat to the vapor at part load operation of the unit.

Abstract: The invention is concerned to control the combustion conditions of a burner 1 supplied with a mixture of pulverized fuel and air. By use of a vortex amplifier 10 in the supply pipe 3, the supply of fuel is interrupted so that the flame is consequently first too lean and then too rich. The temperature of the burner flame is monitored by a photodiode device 6a and an indication is produced of the delay between the operation of the vortex amplifier 10 and the flame temperature passing through that indicating that the flame conditions are optimum. The length of the delay will indicate whether, and to what extent, the flame before the operation of the vortex amplifier was too lean or too rich. Adjacent burners can be controlled by operating the vortex amplifiers associated with each at different regular frequencies.

Abstract: A power plant forced-flow boiler operative with water letdown wherein the letdown water is arranged to deliver heat to partly expanded steam passing through a steam reheater connected between two stages of a prime mover. The heating of steam in the reheater by letdown water will partly or wholly replace the use of live steam for such purpose so that the live steam will be available for driving the prime mover.