Asea Brown Boveri Inc.

Asea Brown Boveri Ag

Abb Management Ag

Abb Alstom Power (schweiz) Ag

Heinz Frey

Kamil Prochazka

Franz Suter

Rico Plangger

Edi Burch

Meinrad Laim

The invention relates to a plate valve (,) as used for the actuator of a control valve. It comprises an inlet (,) with a sealing seat (,) around which the openings of the outlet (,) are arranged, and it has two plates (,), (,), between which there is an interspace (,). Both plates (,), (,) are attached to the housing (,) by springs (,) in a spring space (,). The spring space (,) is operatively connected to a proportional valve by an opening (,) and a line (,). If the pressure in the spring space (,) is lowered by the proportional valve, the additional plate (,) first of all drops as a result and thereby exposes the outflow openings (,) in the large plate (,). There is a slight flow of the oil from the inlet (,) through the orifice plates (,) situated in the plate (,) and through the outflow openings (,) to the openings of the outlet (,). In a second stage, the plate (,) then drops and thereby exposes the openings of the outlet (,). The plate valve (,) is open and the oil can flow unhindered from the inlet (,) to the outlet (,). The plate valve (,) is suitable for an actuator, the control valve of which is to have a short closing time since it has good dynamic characteristics by virtue of its configuration with two plates (,), (,).

Plate valve

This actuating drive (1) for a control valve (2) has a control circuit which sets the actuating drive (1) to correspond with a specified required value from an overriding installation control system. It has, in addition, a main piston (6) sliding in a main cylinder (5) with a drive volume (7), on one side of the main piston (6), which can be acted on in a controlled manner by oil under pressure and has a plate valve (17) fitted upstream of the drive volume (7). The intention is to create an actuating drive, for a control valve, whose dynamic behavior can be improved by relatively simple means. This is achieved by the plate valve (17) being provided with a separate reservoir volume, connected to a drain appliance, for the oil emerging from the plate valve (17).

Actuating drive for a control valve

This operating mechanism for a hydraulic actuator (2) having a pressure-proportional actuating signal is provided with an amplifier (33) for electric signals, with at least one electrohydraulic transducer (24) connected upstream of the hydraulic actuator (2) and with a hydraulic discharge amplifier connected between the electrohydraulic transducer (24) and the actuator (2). The aim is to provide an operating mechanism for a hydraulic actuator having a pressure-proportional actuating signal which can be produced simply and cost-effectively. This is achieved by interconnecting between the actuator (2) and the hydraulic discharge amplifier a piston/cylinder arrangement (4) acting as a transducer.

Operating mechanism for a hydraulic actuator having a

This pipe system has a pressurized feed conduit and an outflow conduit for a hydraulic fluid. It furthermore has parts (6, 8, 10) for connection to a hydraulically actuable device. The intention is to create a pipe system which is improved as regards safety of operation and fire protection and has a smaller space requirement. This is achieved by the fact that the pressurized feed conduit is arranged inside the outflow conduit, this arrangement being maintained right into the interior of the hydraulically actuable device.

Pipe system

A supply circuit for a hydraulic fluid system has at least one pressure generation device, at least one connecting valve, a main line and a safety deactivation unit. The supply circuit permits a hydraulic fluid to be fed in such a way that, in all operating states, occurrence of pressure surges in the system is prevented. The connecting valve is designed as a slide valve with three control edges for regulating filling, operation and testing functions. A plate valve, in fluid communication with the slide control valve, is designed as an outflow amplifier and fulfills the safety related tasks.

Supply circuit for a two-tube hydraulic system

This hydraulic safety and regulating system for a steam feed of a turbine has a rapid-action (4) and a steam regulating valve (3), and a line system monitored by a safety downward-control unit (22). The monitored line system is designed as both a power oil supply and as a safety oil system. This results in a hydraulic safety regulating system which is simple to build and has a reduced number of possible leakage points.

Hydraulic safety and regulating system

This hydraulic valve has a housing (2) with a feed line (12) and a discharge line (14) for a fluid. A sealing point is provided between the feed line and discharge line. A spring acts in the closing direction on the sealing point via a piston. The aim is to create a hydraulic valve which requires no additional energy source. This is achieved when the piston (8, 23) can be moved in the opening direction merely by a total of the pressures present in the feed line (12) and in the discharge line (14).

Hydraulic valve

Connecting valve and hydraulic oil safety and power system in which the connecting valve is used. This connecting valve (1) has at least one sealing location (5) which is actuated by means of a piston/cylinder arrangement. A piston (3) is subjected to a pressure fluid and moved against the force of a spring (7). A connecting valve (1) is created which can be inspected for freedom of movement without influencing operation. The hydraulic oil safety and power system should be particularly operationally reliable by means of the connecting valve (1) in accordance with the invention. This is achieved by at least two pipes (17, 18) entering the drive volume (2) offset in the axial direction, of which pipes only one first pipe (17) is initially effective.

Connecting valve and hydraulic oil safety and power system in which the

This actuating drive (1) has a main piston (4) which can be operated by means of an oil pressure and a pilot control system in effective connection to the main piston (4) by means of a linkage (15). The pilot control system includes a control orifice (14) controlling the oil pressure at the main piston (4) and a pilot control piston arrangement (18) which can be operated hydraulically. The actuating drive (1) is to be designed in such a way that it has improved dynamic characteristics during operation. This is achieved by the fact that the pilot control piston arrangement (18) can be operated by means of an electrohydraulic valve which is triggered by an electronic control unit (31).

Actuating drive

An actuator for a control valve with a control circuit has a main piston which slides in a main cylinder. On one side of the main piston, there is arranged a drive volume, which can be pressurized with oil in a controlled manner, on the other side of which there is arranged an oil-filled buffer volume. The actuator despite having a greater capacity, has a comparatively high dynamic performance which has positive effects particularly when closing the control valve. This is achieved in that the drive volume and the buffer volume can be connected through a connecting line which can be sealed off by a valve. This valve is activated directly hydraulically via a second valve.

Actuator

This hydraulic actuator has a drive volume (11) pressurized by extreme-pressure oil. The oil pressure is converted into a valve movement by a drive piston (10). A spring element acts upon the drive piston (10) in a manner opposing the oil pressure. The actuator is to be constructed such that extreme-pressure oil escaping from the drive volume (11) cannot cause any consequential damage. This is achieved in that the drive volume (11) is completely surrounded by a safety volume (3, 7) filled with low-pressure oil.

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Menziken, Switzerland

Heinz Frey