Abstract: A valve system for gas or liquid, comprising a hydraulic power transmission (19) where the pressure of hydraulic fluid is controlled by fluid pressure actuated members (15) and the changes of the fluid pressure actuate operative members (5, 7, 10) of the valve system, where the fluid pressure actuated members and the operative members comprise a tubular expandable bellows (10, 14, 25) with one gable (21) closed and the other (22) connected via tubes (11, 23) or similar to other expandable bellows (10, 14, 25) in the valve system and the thus arisen closed space in filled with hydraulic fluid (24), and that the expandable bellows (10) in the operative member stand in connection with a valve body (5) in a valve tube (1) and that the fluid pressure actuated members (15) is placed outside the valve tube (1). The valve body (5) is movable in the longitudinal direction of the valve tube (1) and in close contact with a seat (3) when the valve system is closed.

Abstract: A minimum flow valve device includes a housing providing a liquid passageway therethrough having an inlet end and an outlet end; a guide element mounted in the liquid passageway which provides an internal chamber that is open towards the inlet end of the liquid passageway, the guide element including a discharge orifice communicating with the internal chamber; an unloading pipe extending through the housing and communicating with the discharge orifice; an annular non-return valve element; and a valve sleeve member connected to the non-return valve element and extending within the internal chamber. The valve sleeve member includes orifices such that when the non-return valve element and the valve sleeve member are positioned to block liquid flow through the liquid passageway, liquid will flow through the discharge orifice and out the unloading pipe.

Abstract: The present invention provides a method for producing hot rolled steel products having high strength and ductility. The method is particularly suitable for low alloy structural steels which contain about 0.02 to 0.15 wt. % C and 0.100 to about 0.015% Nb, the higher Nb percentage being used for steels with the lower C content and vice versa. In the method, the steel is heated to a temperature of about 1150.degree. to about 1250.degree. C. The steel is then rolled during a first sequence of passes so that the average austenite grain size at the end of the first sequence stays below about 50 um and so that the last pass in this sequence is conducted within the temperature range of about 950.degree. to 1100.degree. C. In a second rolling sequence directly following the first sequence, the rolling is continued with further reductions that do not exceed about 15% in each pass. Subsequently, the steel may be cooled to ambient temperature in a conventional manner.

Abstract: The invention relates to a steel and a process for its manufacture which is suitable for the production of springs, especially leafsprings for vehicles. The steel which is vacuum-treated is an ordinary low-carbon steel with 0.20-0.04% C. Its composition is incidentally characterized in that the oxygen content does not exceed 0.040% and in that boron is added to an amount of 0.002-0.004% and titanium to an amount of 0.015-0.050%. The addition of boron causes the hardenability to increase greatly, thus making it possible to keep the carbon content low and, in consequence, reducing the danger of destructive decarbonization.A characteristic of the process of production consists in the fact that the steel is produced in an oxygen converter in such a manner that the nitrogen content in the ladle does not exceed 20 ppm, in that it is subsequently subjected to vacuum treatment and in that Al is added so that the amount of uncombined oxygen drops to max.