US 7,066,203 B2 · Gas flow control

Abstract

Gas flow control is addressed using a controllable approach that facilitates safe operation. According to an example embodiment, a control arrangement for gas flow comprises two main valves connected in series and two servo valves operated by an actuator, the opening of the main valves being controlled via said servo valves. The main valves are operated by means of diaphragms limiting a first gas chamber, wherein the first servo valve is connected to the first gas chamber of the first main valve, to a second gas chamber in the inlet area of the first main valve and to the first gas chamber of the second main valve. Due to this construction a leakage gas flow out of the first gas chamber of the first main valve leads, if the first servo valve fails, to an increase in pressure in the first gas chamber of the second main valve, whereby it is ensured that the main valve is safely closed.

Claims22

Dependent claims

A gas flow controller comprising:

first and second main valves connected in series and first and second servo valves operated by an actuator, the opening of the first and second main valves being respectively controlled via said first and second servo valves, each of the main valves being operable by means of a diaphragm limiting a first gas chamber for each main valve;
and
said first servo valve being connected to said first gas chamber of the first main valve via a first gas line, to a second gas chamber in the inlet area of said first main valve via a second gas line and to said first gas chamber of the second main valve via a third gas line.

Dependencies are inferred from the claim text.

Gas flow control

Life of this patent

Gas flow control

Life of this patent

Abstract

Claims22