None of us ever expect to face disaster. For the most part, people are generally safety conscious. It is usually the unexpected things that catch us off guard, such as an accident. Many times neglect, or lack of maintenance (even if unknown) can cause an accident. That is why we offer our experience with safety issues surrounding HHO that may help you prepare for disaster, and even avoid it. First let's talk about the various components of a typical electrolyzer configuration. Click on each of the links below for information on device configurations.

Electrolyzers
Reservoirs & Gas Separators
Bubblers
Flash Arrestors

To Avoid Disaster, or Control Disaster?
That is the question.
As I tell everyone that asks me about HHO safety; expect to have a flashback. If you expect it and plan for it, you can prepare yourself to avoid it or control it. Personally, I prefer to control a flashback. But in all reality, we must do both. HHO is an extremely fast burning fuel, and should be highly respected. It can be ignited without any external oxygen source. We must avoid the inevitable, yet have the ability to control what we can't avoid. Sound confusing? Let me explain.

Follow the Path of the Gas.
First, acquaint yourself with your setup, and make sure you are aware of where the HHO is at all times. Be aware of every hose, barb fitting, elbow, gas pocket and device. Anywhere HHO resides, you have the potential for a flashback. Pay special attention to large pockets of gas in areas like Wet Cell containers and Dry Cell reservoirs. If large enough, these can pack a lethal punch in the event of a flashback. The most vulnerable place in any HHO setup is the point of exit. Avoid flames or sparks directly in front of your exit hose, unless you are using a torch designed specifically for sustaining a flame. The point of exit isn't the only vulnerable part, though. Sometimes a flashback can occur from within. In the early days of my research, I once had an electrical short in the bottom of a glass jar cell (cookie jar size). Of course, at the time, I didn't realize how dangerous it was to use a glass jar. I didn't know I had a short until it ignited the gas all the way up through the electrolytic bath and into the large pocket of HHO at the top. The blast blew off the metal lid which was securely screwed onto the jar. The noise left my ears ringing for hours. Fortunately, the glass didn't shatter. I should have taken proper steps to avoid the short, yet had blast relief in place to control the outcome of the blast.

Blast Control
Secondly, let's consider blast control. In every HHO setup, there is generally an area where HHO is concentrated in a particular area. This area can be the gas pocket at the top of a reservoir or Wet Cell container, or within a pressurized chamber. Sometimes this area can be a Liter in size or more. This is especially true for reservoirs or cell containers if the electrolyte level is allowed to fall below a certain level. This scenario should be avoided by keeping the electrolyte level high enough to prevent large standing pockets of HHO from forming. When you have the potential for a large pocket of HHO to form, you should install one or more pressure relief valves. They should be designed to open around 20-PSI over the ambient pressure of the entire system. For instance, if you are running your system at 20-PSI, the blast relief port should open at 40-PSI. The design should also be able to safely dissipate a flashback and reseal itself, automatically. We recommend the opening of the pressure relief valve to be AT LEAST 1/5th the diameter of the container it is attached to for each Liter of standing HHO. This number can be combined by installing multiple valves. In other words, if your reservoir has a 3 inch diameter with no more than 1 Liter of standing HHO, your blast relief should be at least .6 inches diameter. Of course, the larger the blast relief port, the better. To provide point of contact protection, we developed the EPDv2, or Explosive Pressure Dissipater. It fits a 3/4 threaded port, and safely dissipates a blast of up to 1 Liter of HHO. It opens at about 20 PSI above normal atmosphere. A single EPDv2 works well on devices from 3 to 4 inches in diameter. Not only that, every part of the EPDv2 is user serviceable.

Building Materials
This is one of the most important topics in HHO. Many experimenters starting out in HHO take the least expensive route. This is understandable, considering how expensive the components of a professional HHO system can be. Not to mention the time and research that goes into developing a high quality electrolyzer. Besides your time, the corrosion resistant metals alone can be a rather expensive investment. If you intend to seriously undertake HHO experimentation, invest in a professionally made electrolyzer. Avoid electrolyzer designs that are made of glass. Stick to the highly efficient Dry Cell designs. If you just want to try it out to see if you are interested, you can still start with Wet Cells, but be sure to implement proper safety precautions.

Electrode Metals:
Always use non-corrosive metals inside the electrolyzer, like Stainless Steel (some even use nickel, titanium or platinum). We recommend 304L or 316L Stainless Steel. Never make electrical connections in a Wet Cell chamber with copper wire, solder, or push-on electrical connections. The electrolyte can be highly corrosive, and will destroy these connections increasing your risk of a short or spark. In ANY electrolyzer design, whether Wet or Dry, bolt all connections inside and outside securely to avoid shorts or failure. Any loose connections will quickly overheat, especially if you are using high current.

Wire Gauge:
Be sure to use the proper gauge wire. This means use one size larger than the maximum amperage you expect to input. The following wire gauges are our recommendations, and do not necessarily represent pre-established wire tolerances.
10 gauge: 0-8 amps
8 gauge: 9-20 amps
6 gauge: 21-35 amps
4 gauge: 36-55 amps
2 gauge: 56-65 amps

Plastics:
PVC is okay to use for bubblers, cell containers, outer plates and gaskets, provided the overall operating temperature of your cell does not reach 140° F. PVC can soften with higher temperatures and cause failure. Do not use PVC for reducers in critical junctions. ABS should be used in these critical areas due to it's higher strength. Use of Acrylic is often sought after because it can be crystal clear and glass like. This is okay for bubblers. It shouldn't be used for Dry Cell end plates unless your electrolyte concentrations are very low. Certain electrolytes can attack acrylic over time. We recommend using Polypropylene anywhere possible, because it is rated "A" for all acids and bases. It has a normal operating temperature range of 0 to 180° F. If you have any questions about building materials, feel free to contact us. We will be happy to answer you as soon as possible.

Know how much you are producing!
Many experimenters will plan their build around how much HHO they THINK it will produce. This is a huge mistake. It is true that experienced builders can estimate gas output by simply looking at a hose in a bucket, or looking at the size of the cell. Don't make this a habit. Test your cell and know how much HHO it produces. You must understand that every cell configuration is different. It's output is subject to voltage, amperage, electrolyte, plate material, temperature and (guess who?) the operator! Every cell configuration is different, because everyone is different. You may have mixed your electrolyte differently, used thinner or thicker gaskets, or even implemented your own voltage and amperage scheme.

When you have your cell complete, you should perform two LPM tests. One should be performed while the cell is cool. Another should be performed after the cell has been conditioned for a few hours or days. DO NOT rely on traditional Flow Meters that are normally calibrated for a single gas like Hydrogen or Oxygen. For instance, a Flow Meter calibrated for Oxygen won't give an accurate measurement for HHO because you are also introducing two additional parts Hydrogen. An accurate flow test can be performed cheaply, and easily. You will need a five gallon bucket, drinking bottle and a stopwatch or clock. You can use anything from 500mL to 2 or 3 Liters. Push the bottle into the bucket of water and allow it to fill completely. Put the cap on and take it out. Turn it upside down and insert it back into the water with the cap down. Remove the cap. Insert your output hose into the neck of the open bottle and turn your electrolyzer on. Time how long the bottle takes to fill completely. This is your volume-per-minute test.
For example: If your bottle is 2 Liters in size and takes 2 minutes to fill, your cell has an output of 1 Liter Per Minute. If it fills in 20 seconds, your cell has an output of 6 Liters Per Minute. Now, without question, you have an accurate measurement. Now that you have an accurate measurement of the output of your cell, you can implement appropriate safety measures. Another method we recommend is building and using a YAHHO Flow Meter by LutherP40 on YouTube.