Back-pressure prevention devices in fuel gas systems may include check valves, three-way valves, and normally closed automatic shut-off regulators.

Back-pressure prevention devices in fuel gas systems may include check valves, three-way valves, and normally closed automatic shut-off regulators.

• A. All Choices Are Correct
• B. Check Valves
• C. Three-Way Valves
• D. Normally Closed Automatic Shut-Off Regulators

Answer: (A)

Back-pressure prevention in fuel gas systems is about keeping gas moving only toward the intended direction and stopping any tendency for pressure or gas to push backward toward the supply. Check valves are the classic solution: they permit flow in one direction and automatically close if downstream pressure tries to push gas back upstream, blocking reverse flow. Three-way valves offer directional control, so they can be arranged to isolate a branch or redirect flow in a way that prevents a back-pressure path from affecting the supply side. Normally closed automatic shut-off regulators add a safety mechanism that automatically shuts off flow when conditions indicate a fault or abnormal pressure, preventing continued flow into a line that could experience back-pressure or leakage. Since each of these devices can serve to prevent back-pressure when used appropriately, all of the listed options together represent valid back-pressure prevention devices.

Back-pressure prevention in fuel gas systems is about keeping gas moving only toward the intended direction and stopping any tendency for pressure or gas to push backward toward the supply. Check valves are the classic solution: they permit flow in one direction and automatically close if downstream pressure tries to push gas back upstream, blocking reverse flow. Three-way valves offer directional control, so they can be arranged to isolate a branch or redirect flow in a way that prevents a back-pressure path from affecting the supply side. Normally closed automatic shut-off regulators add a safety mechanism that automatically shuts off flow when conditions indicate a fault or abnormal pressure, preventing continued flow into a line that could experience back-pressure or leakage. Since each of these devices can serve to prevent back-pressure when used appropriately, all of the listed options together represent valid back-pressure prevention devices.