The SafeGuard Turns a Standard LPG Regulator Into a Smarter, Safer, Leak-Monitoring Watchdog
When a gas leak is detected a servo shuts off the supply automatically — and it can even warn you when the cylinder is getting low.
Pseudonymous maker "drabtech" has designed a device that improves the safety of liquified petroleum gas (LPG) regulators — by constantly checking for leaks and tracking the amount of gas left in the cylinder.
"The idea for SafeGuard came from a very real fear. After witnessing a kitchen fire at my neighbor's house, I realized how easily a small mistake or unnoticed leak could turn into a disaster," drabtech explains. "This project was built under pressure, tested in my own home, and refined through plenty of trial and error late nights, burnt fingers from soldering irons, and more failed 3D prints than I'd like to admit. There was a moment around 2 AM when everything finally worked together, and that's when I knew this was something worth sharing."
The SafeGuard system is powered by an Espressif ESP32-C6, linked to the popular and low-cost MQ-2 gas sensor and four 50kg-capable load cells connected to a suitable amplifier module. The latter is used to weigh the gas cylinder, triggering an alert when it drops to a weight equivalent to 10% remaining gas; the former, naturally enough, samples the air in order to detect leaks before they can become a problem.
SafeGuard isn't just about monitoring, though: the 3D-printed add-on includes a servo motor that shuts the gas supply off, fitting straight onto standard LPG regulators without needing any permanent modification. The system is not, however, intrinsically safe: while it's all low-voltage DC stuff, there is the theoretical risk of a spark when the servo motor is activated — though it's considerably less likely than an unnoticed gas leak causing a problem.
When a leak is detected, the valve is closed and alerts triggered — audible, visual, and remote to the owner's smartphone. In testing, the system developed on its creators' vision: three leaks were detected and correctly alerted with no false positives, and the low gas alert system triggered correctly with a calculated 9.8% gas remaining in the cylinder.
The project is documented in full, including 3D print files and source code, on Instructables.