Valves and control systems for pressure relief

A system for overpressure control, the system comprising:

• at least two valve assemblies positionable on a bypass conduit downstream from a connection point with a main conduit, each of the two valve assemblies comprising:
• a valve actuation system including a source of actuation fluid,
• a valve housing having a longitudinal bore therethrough, and including an upstream connection and a downstream connection, and
• a ball valve positioned in the valve housing between the upstream connection and the downstream connection, the ball valve comprising:
• a valve body having a throughbore, wherein an open position of the valve body provides flow-through alignment of the throughbore with the upstream and downstream connections of the valve housing, and a closed position of the valve body provides an out of flow-through alignment of the throughbore with the upstream and downstream connections of the valve housing,
• an upstream seal comprising an outward facing surface positioned perpendicular to the longitudinal bore of the valve housing, wherein a fluid pressure on the outward facing surface forces the upstream seal against a sealing face of the valve body, and
• a downstream seal;
• a pressure sensor configured to detect a fluid pressure in the main conduit wherein the pressure sensor comprises:
• at least two pressure transducers positioned in a main housing of the system, and
• a pressure chamber having a deformable diaphragm surrounding a pressure fluid within the pressure chamber,
• wherein the pressure fluid is fluidly connected to the at least two pressure transducers to transfer an external fluid pressure on the deformable diaphragm to the at least two pressure transducers, and
• wherein the pressure chamber is configured to be positioned on the main conduit line such that the fluid pressure in the main conduit line comprises the external fluid pressure on the diaphragm;
• and
• a control system in electronic communication with the pressure sensor and the valve actuation system,
• wherein the control system is configured to receive a signal from the pressure sensor indicating the fluid pressure in the main conduit, and communicate with the valve actuation system to change a position of the valve within the valve housing, such that when the fluid pressure in the main conduit exceeds a user-defined high pressure limit the valve is opened, and when the fluid pressure in the main conduit falls below a user-defined low pressure limit the valve is closed.

A method for overpressure control in a fluid line, the method comprising:

• providing an overpressure relief system comprising:
• at least two valve assemblies, each comprising:
• a valve actuation system including a source of actuation fluid, and
• a valve housing having a longitudinal bore therethrough, the valve housing comprising an upstream connection, a downstream connection, and a valve positioned therebetween;
• at least one pressure sensor comprising:
• at least two pressure transducers, and
• a pressure chamber having a diaphragm surrounding a pressure fluid within the pressure chamber, wherein the pressure fluid is fluidly connected to the at least two pressure transducers to transfer an external fluid pressure on the diaphragm to the pressure transducer, and wherein the diaphragm comprises a flexible and deformable structure;
• and
• a control system in communication with the pressure sensor and the source of actuation fluid;
• attaching a first end of a first bypass conduit to the upstream connection of the valve housing of a first valve assembly, and a second end of the first bypass conduit to the fluid line;
• attaching a first end of a second bypass conduit to the downstream connection of the valve housing of the first valve assembly;
• attaching the pressure chamber of a first pressure sensor on the fluid line such that an outward facing side of the diaphragm is in contact with a fluid in the fluid line;
• and
• setting a high pressure limit and a low pressure limit for the first valve assembly using a user interface on the control system,
• wherein the control system is configured to receive a signal from the at least one pressure sensor indicating a fluid pressure in the fluid line, and communicate with the valve actuation system of the first valve assembly to change a position of the valve, such that when the fluid pressure in the fluid line exceeds the high pressure limit the valve is opened, and when the fluid pressure in the fluid line falls below the low pressure limit the valve is closed.