Leak test system
AssigneeWoodbury Leak Advisor Co.
InventorsH. Allan Woodbury, James R. North
Life of this patent
Estimating the term…
Abstract
A leak test system is disclosed for a double block and bleed valve arrangement, the system including a second vent valve disposed along the bleed line and a secondary gas supply line connected to the bleed line for introducing gas at a known pressure into the bleed line to test the valves and ensure that they are not leaking. A pressure transducer is positioned to monitor the pressure within the bleed line. The pressure transducer is in communication with a processor which generates an alarm if the pressure in the bleed line changes, thereby indicating a leak. A method for testing each valve in the arrangement is also disclosed.
Claims23
A leak test system for a double block and bleed valve arrangement having first and second safety shutoff valves disposed along a gas supply line, and a vented bleed line extending from the gas supply line between the first and second safety shutoff valves with a vent valve disposed along the bleed line, the leak test system comprising:
- a second vent valve disposed along the bleed line downstream from the vent valve;
- pressure monitoring means in communication with the bleed line line for monitoring pressure in the bleed line between the first and second vent valves and for generating signals indicative thereof;
- and
- processor means disposed in communication with the pressure monitoring means for processing said signals.
A leak test system for monitoring leakage through a first vent valve disposed on the bleed line of a double block and bleed arrangement, the system comprising:
- a secondary vent valve disposed along the bleed line at a point distal to the first vent valve;
- pressure monitoring means for monitoring pressure in the bleed line between the first and second vent valves;
- processor means disposed in communication with the pressure monitoring means for receiving signals from the pressure monitoring means;
- and
- secondary gas supply means connected to the bleed line between the first and second vent valves for introducing gas into the bleed line between the first and second vent valves to achieve a known pressure.
A method for testing leakage comprising:
- (a) selecting a double block and bleed valve arrangement having a gas supply line, first and second safety shutoff valves disposed along the gas supply line in series, a vented bleed line extending from the gas supply line between the first and second safety shutoff valves and a vent valve disposed along the bleed line between the gas supply line and a vent;
- b) disposing a second vent valve on the bleed line between the vent valve and the vent;
- c) closing the second vent valve;
- d) selectively opening and closing the other valves while the second vent valve remains closed and prior to a predetermined time interval to isolate gas supply line segments for detection of leaks through valves bounding the segments;
- e) causing known gas pressure to be present in the bleed line between the first and second vent valves at a beginning of the time interval;
- and
- f) generating signals indicative of gas pressure during the time interval and identifying any change in pressure.
Dependencies are inferred from the claim text.