Abstract: Method for manufacturing a double-walled heat exchange tube with leak detection, wherein inner tube is slipped into an outer tube, after a surface profiling has been provided on at least the outer surface of the inner tube or the inner surface of the outer tube, and at least the outer surface of the inner tube or the inner surface of the outer tube has been provided with a layer of soldering material. After the tubes have been slipped into one another, the inner tube is expanded such that the outer tube is expanded as well and the surface profiling forms a leak detection channel between the two tubes, and the soldering material between inner and outer tube is caused to melt. In a heat exchange tube thus obtained at the location of the contact between the inner and outer tube, a film-thin, optionally porous layer from soldering material is present, which layer is bonded, through melting, to both the inner tube and the outer tube.

Abstract: Method and apparatus for operating a closed hot water installation provided with a pipe system, a boiler, heat exchangers, an expansion tank, a water make-up provision and a de-aerator, the method including the steps of opening a non-return valve to allow air to escape, detecting a water level in the de-aerator, feeding water to the closed installation when the level falls below a predetermined level, blocking opening of the non-return valve until the water level has fallen to a first level and starting the feed of water when a second lower level is reached.

Abstract: A heat exchanger tube is composed of a metal outer tube having an inner profile and a metal inner tube having an outer profile, wherein the profiles are in an undercut engagement with each other so that the inner and outer tubes are in rigid abutment and at least one longitudinal channel, formed between the outer tube and the inner tube is provided for leak detection and the heat exchanger tube may be manufactured by designing the profile so that the inner and outer tubes may be screwed or slid into one another to provide a rigidly abutting configuration.

Abstract: A method for expansion control in a closed fluid circulation system with varying temperature, in which system air is drawn from the circulating fluid through the formation of an air head wherein air to be withdrawn is collected and from which air can be blown off, controlled by a valve, to the environment or a receiving space, while further off, measures are taken for taking up, when the temperature varies, an attendant expansion and shrinking of the fluid within the closed system, and measures for enabling adding fluid to the system, which fluid is withdrawn from an external stock of fluid under pressure, and the air head volume is measured and when a predetermined value is exceeded, a fluid valve is opened through which fluid is introduced into the air head until the volume of the air head is substantially equal to the predetermined value and the fluid valve is closed.

Abstract: A method and apparatus for deaerating a liquid in a substantially closed liquid circulation system, wherein an amount of liquid is withdrawn from the circulation system and is introduced into a closed reservoir via a valve which is alternately open and closed, wherein by a pump which is operative in the open as well as the closed positions of the valve an underpressure can be created in the reservoir for the purpose of deaerating the liquid, and the liquid can be sucked from the reservoir and added to the circulation system again, separated air being discharged via a vent unit to the environment. For the valve adapted to be opened and closed alternately, preferably a throttling valve is used.

Abstract: A method and device for maintaining a fluid at a working pressure in a substantially closed fluid circulation system wherein the temperature of the fluid can vary and which is preferably deaerated continuously. The maintenance of a working pressure is realized by keeping the system filled automatically by connecting said system, by means of a closable connection, to a stock of fluid which is under atmospheric pressure, the fluid circulation system and the stock of fluid being connected directly, which connection is opened at and below atmospheric pressure at the location of the connection and, when the working pressure rises, is automatically closed at atmospheric pressure at the location of the connection. If so desired, replenishment of the stock of fluid, which is preferably disposed in the vicinity of the highest point of the system and may serve as expansion possibility for the system, may be effected automatically.

Abstract: A fastening element with an adjustment flange and an eccentric segment for objects to be suspended as, in particular, heating elements or convectors, which engages into bores of an attachment wall and a rear wall of the object lying opposite each other, has between an outer adjustment flange and an inner flange an adjustment eccentric clamped eccentrically with respect to the flanges for compensation of alignment errors of the bores, whereby the surface of the inner flange facing away from the eccentric comes to rest against the attachment wall externally of the bore receiving a bolt and the adjustment eccentric slid loosely upon the bolt is arranged only in the area of the bore of the rear wall to be pivotable around the bolt from outside of the bore.

Abstract: The liquid flowing through a heat circulation system including a boiler can be maintained in an air absorbing condition even at the highest elevation in the circulation system. The air absorbing condition is attained by alternately subjecting the liquid in the boiler to the high pressure of the circulating system and at least to atmospheric pressure and effecting deaeration while the liquid is at atmospheric pressure. During deaeration the liquid is blocked from flowing from the boiler into the circulation system. Following deaeration, the liquid is brought up to the high pressure of the system before it is directed back into the system.

Abstract: An economical pipe for use in a utility or service system, particularly a circulating hot water supply system or a heat exchanger system requiring outgoing and incoming hot water paths. The pipe possesses a partition wall dividing it longitudinally into two ducts.

Abstract: In a method of reducing the gas content of a liquid in which the liquid is propelled, preferably in a closed circuit, by a centrifugal pump (1), an improved degasification capability is achieved by extracting a portion of the liquid from the suction side of the pump blades (5, 18) in the region of the impeller axis, preferably via a passage (20) extending through a hollow drive shaft (21) of the impeller (14), and conducting this portion of the liquid through a liquid stilling zone (55, 56) where fine gas bubbles are separated from the liquid. The degassed liquid is preferably returned to the liquid in the inlet pipe (15) upstream of the pump (1), where it is set in rotation by a helical member (10). The liquid extracted from the pump (1) may be sucked out by means of an auxiliary rotary pump (3), or it may be entrained by injecting a high speed stream through a venturi nozzle (39) housed by the impeller (14) coaxially with the hollow drive shaft ( 21).

Abstract: In a closed circulation system containing a constant amount of liquid, a force is generated for driving the liquid through the system. A branch line extends from the circulation line of the system at a point adjacent to and closely downstream from the location at which the force generating circulation is effected. A collecting chamber is provided in the branch line spaced from the circulation line. Gases dissolved in the liquid are released at the location of the force generation and the gases are removed through the branch line and the collecting chamber. Downstream from the branch line the liquid is either cooled or returned at least to normal pressure for its continued circulation so that it is able to absorb air from the air accumulations within the system with which the liquid comes into contact.

Abstract: An apparatus for venting and/or degassing a pipeline system includes an upwardly extending casing formed of a top part and a bottom part with a cap located within the casing and extending transversely of the upward direction in the region where the top part is connected to the bottom part. A valve is located in the upper end of the top part and has a horizontally extending valve needle projecting into the interior of the casing. A float needle is located within the top part of the casing and is in interengaged contact with the valve needle. A float is freely slidable on the float needle between the cap and the upper end of the casing. The top part of the casing and the float needle are dimensioned so that the float can move upwardly and downwardly on the float needle from the region of the cap toward the valve needle so that during a pressure increase within the casing up to a predetermined value there will be an accurate safety dimension maintained between the liquid surface in the casing and the valve.