HHO Safety Valve “Piston Popper”

24,00 € each Weight: 100 g


HHO safety valve protects your vehicle from the unlikely occurrence of a flame emerging from the engine air intake. The safety valve is spring loaded and designed to temporarily open when a flashback causes extreme pressure.

  • Automatically resets


When a flashback occurs, the flame in the air inlet travels back to the HHO bubbling tank in a split second, and the gas above the water level immediately explodes.

Most bubbler tanks are not strong enough to withstand the explosion pressure of the HHO gas.

During a flashback, the piston spring will collapse allowing high pressure to escape through the exhaust ports, relieving pressure instantly.

Then, the stainless steel spring pushes the piston down, to automatically seal the tank.

Simple but effective way to control flashback!


  • Four 12.5mm (1/2 inch) exhaust ports provide pressure relief
  • Automatically resets and in a split second is ready to protect your vehicle against another flashback


It has internal moving parts:

  • Stainless steel spring
  • with an O-ring at the base, an axial moving piston made of Acetyl provides the perfect seal

The piston is made of acetyl and is machined on a lathe. Moving parts are enclosed with (unscrew) removable lid on top (1 1/2 inch water pipe thread) for easy opening and inspection.

The bottom of the housing is threaded polyethylene (1 inch water pipe thread) for attachment to the bubbler tank.

A nut (water pipe thread) is used inside the bubbling tank for fixing the safety valve, providing strength to withstand a flashback.

There is also an O-ring mounted between the housing and the outside of the bubbler for a 100% airtight seal.


Other methods include "In line arresters" and "seals blowing out". Blown seals are very effective and 100% guaranteed to work, but do not return to automatically seal.

So far we have not seen "in line arresters" we can trust. Most do not arrest the flame, some end up melted, and some blow through. They all eventually fail causing a violent explosion in the bubbler.

Our HHO safety valve "Piston Popper" has the advantage of being effective against flashbacks and reseals itself ready for another flashback if it happens.


In the case of an explosion, the bubbler must exhibit water above the bottom of the tank, or the electrolyte reservoir may explode!

If you experience a flashback, it is advisable to open the HHO Piston Popper (unscrew the top) and make sure it is free of debris and not blocked!

The bubbler tank should have walls of at least 2 mm thick (if made from plastic materials), to provide the necessary strength to withstand the force of an explosion, otherwise it may break before the "Piston Popper "relieves the pressure.

Caution: Never install our product in a glass or any other fragile container!!!


We absolutely guarantee this product for materials and labor.


AutoHydrogen not liable for damages or injuries that occur due to improper use of this product. If in doubt, email us and ask if it is right for your application.

Common sense is all that is needed. Installation is a breeze.