Debris resistant internal tubular testing system

A tubular string testing system for use with a tubular string having a flow passage extending longitudinally through the tubular string, the testing system comprising:

• a valve which selectively permits and prevents fluid communication between sections of the flow passage;
• a bypass passage which provides fluid communication between the sections of the flow passage when the valve is closed;
• a filter which filters fluid that flows through the bypass passage;
• at least one check valve which permits flow in one direction through the bypass passage, and prevents flow in an opposite direction through the bypass passage, wherein the check valve is positioned in a nonmagnetic portion of a housing assembly;
• and
• a magnetic device which causes the check valve to permit flow in both directions through the check valve.

A tubular string testing system for use with a tubular string having a flow passage extending longitudinally through the tubular string, the testing system comprising:

• a valve which selectively permits and prevents fluid communication between sections of the flow passage;
• a bypass passage which provides fluid communication between the sections of the flow passage when the valve is closed;
• a filter which filters fluid that flows through the bypass passage;
• at least one check valve which permits flow in one direction through the bypass passage, and prevents flow in an opposite direction through the bypass passage;
• and
• a magnetic device which causes the check valve to permit flow in both directions through the check valve.

A method of testing a tubular string, the method comprising:

• permitting fluid to flow through a bypass passage which connects sections of a flow passage extending longitudinally through the tubular string, a filter filtering the fluid which flows through the bypass passage;
• a valve of a tubular string testing system preventing flow of the fluid between the sections of the flow passage through the valve;
• and
• flow through the bypass passage being prevented in response to a predetermined pressure differential being created across the filter, wherein the filter displaces in response to the predetermined pressure differential being created across the filter.

A method of testing a tubular string, the method comprising:

• permitting fluid to flow through a bypass passage which connects sections of a flow passage extending longitudinally through the tubular string, a filter filtering the fluid which flows through the bypass passage;
• a valve of a tubular string testing system preventing flow of the fluid between the sections of the flow passage through the valve;
• flow through the bypass passage being prevented in response to a predetermined pressure differential being created across the filter;
• at least one check valve permitting flow in one direction through the bypass passage, and preventing flow in an opposite direction through the bypass passage, wherein the check valve is positioned in a nonmagnetic portion of a housing assembly;
• and
• operating a magnetic device, thereby causing the check valve to permit flow in both directions through the check valve.

A method of testing a tubular string, the method comprising:

• permitting fluid to flow through a bypass passage which connects sections of a flow passage extending longitudinally through the tubular string, a filter filtering the fluid which flows through the bypass passage;
• a valve of a tubular string testing system preventing flow of the fluid between the sections of the flow passage through the valve;
• flow through the bypass passage being prevented in response to a predetermined pressure differential being created across the filter;
• at least one check valve permitting flow in one direction through the bypass passage, and preventing flow in an opposite direction through the bypass passage;
• and
• operating a magnetic device, thereby causing the check valve to permit flow in both directions through the check valve.