FLASHBACK

[theglasszone]

Oooo, thanks Ziggy! I knew that bathroom scale would come in handy for something SOMEDAY

~De

[ziggys]

Originally Posted by theglasszone

Oooo, thanks Ziggy! I knew that bathroom scale would come in handy for something SOMEDAY

~De

LOL! It's also good for weighing my cat.

[Blueflameart]

Such conflicting info out there ... both AmeriGas and Suburban propane here in S.C. said no no no to flashback arrestors. They say that a line running 1 - 10 psi could never "come back" through a line with psi running through it. They said only when the tank has just a little bit and pressure has somehow revered could it even be possible.

BY NO MEANS am I saying don't or do use one. I am NOT an expert but after talking to many experts, owners and people that work with propane everyday it seems very conflicting imho. Dunno but what they are saying does make sense and having one on there for "peace of mind" makes really great sense too!

[andreajane]

My husband has worked with flammable gasses, tanks, torches and ventilation issues for thirty years. I swear if I didn't have him to rely on I would be totally confused.


Andrea

[Blueflameart]

Originally Posted by andreajane

My husband has worked with flammable gasses, tanks, torches and ventilation issues for thirty years. I swear if I didn't have him to rely on I would be totally confused.


Andrea

Heya Andrea

What does he say about them? Hope all is well

[theglasszone]

BUMP (for the benefit of some newer members!)

De

[ruca]

Originally Posted by Blueflameart

Such conflicting info out there ... both AmeriGas and Suburban propane here in S.C. said no no no to flashback arrestors. They say that a line running 1 - 10 psi could never "come back" through a line with psi running through it. They said only when the tank has just a little bit and pressure has somehow revered could it even be possible.

BY NO MEANS am I saying don't or do use one. I am NOT an expert but after talking to many experts, owners and people that work with propane everyday it seems very conflicting imho. Dunno but what they are saying does make sense and having one on there for "peace of mind" makes really great sense too!

I've seen a lot of conflicting info, too, & by no means am I an expert on shop set up or anything, but I am absolutely neurotic about safety, so this is my opinion on flashback arrestors:

Whether you have a surface mix or premix torch, just hook them up. Even if it's a one in a million chance you will blow up, FBAs are such an inexpensive piece of equipment compared to what the cost of setting up shop is that it is better to be safe than sorry. Your life is more important than saving $60. And even if there was an incident & you escaped with little to no bodily harm, I know if I had a tank explode I'd sure as sh!t be too scared to ever torch again - or atleast for a very long time.

(P.S. Blueflame- Even though I quoted you & am saying "you" in this statement, I don't MEAN you in particular. I just was thinking off of your statement, you means everyone. LOL you probably got that, sorry, I ramble)

[melabe]

I just ordered a mega minor torch. When placing the order I asked about flashback arrestors and was told that I did not need one as my torch is a surface mix. ????? any feedback?

[ruca]

Originally Posted by melabe

I just ordered a mega minor torch. When placing the order I asked about flashback arrestors and was told that I did not need one as my torch is a surface mix. ????? any feedback?

there's debate on the issue, & its very unlikely that it will happen, but it has happened before. i say always use flashback arrestors, no matter what. if i were you, i would hook them up.

it's better to be safe than exploded.

[melabe]

I asked that question prior to reading everything. Man this torch stuff get confusing and complicated.

[theglasszone]

Melabe~~~

In my opinion, no confusion, no complication, no debate! And I agree with Jes...

The way I see it, USE FLASHBACK ARRESTORS, NO MATTER WHAT OXY/FUEL TORCH YOU'RE ON!!!! That way, if they are never needed, it's wonderful. Alternatively, if you do have a flashback (no matter how unlikely or random the possibility), the "Why didn't I..." question will never be asked!!! (Assuming you survive, along with your house and neighborhood, in order to be around to ask!)

De

[Alison D]

Remember, anyone running natural gas, Carlisle makes the firecheck for your natural gas line.


Alison

[RaymondMillbrae]

Yes! You need a flashback arrestor.

My DWP has been distracted a few times and turned on her Mega Minor (oxy first, THEN propane) and gotten a loud crack/pop.

This can only mean one thing.

Make sure you have a flashback arrestor protecting your PROPANE TANK.

I know some folks will say that a hose flasback arrestor is the think to do. But in my opinion, guard the PROPANE TANK with your life - hence, purchase a regulator flashback arrestor.

Or you can also order the set (regulator and hose arrestors) from ARROW SPRINGS. They have a great price on this package! (Make sure you also order a set of quick connects to make your life easier).



Flashback Arrestors
American
Complete 2 Piece Set ..... $65.00 Part# FLASHAR-USA
1 Piece Oxygen Only ..... $34.00 Part# FLASH-OXYUSA
1 Piece Fuel Gas Only ..... $34.00 Part# FLASH-PROUSA
Import
Complete 2 Piece Set ..... $30.00 Part# FLASH-CHIN
1 Piece Oxygen Only ..... $15.00 Part# FLASH-OXYCHN
1 Piece Fuel Gas Only ..... $15.00 Part# FLASH-PROCHN



Best wishes.

In Christ: Raymond

[Shane]

I have one on my propane but not my oxycon.

[melabe]

Thanks for the price range. Cheap when compared to a life!

[ICBeads]

Originally Posted by Shane

I have one on my propane but not my oxycon.

You don't need an arrestor on your oxycon. An oxycon typically contains 2 small canisters that alternate filling with oxygen at about 20 psi per canister and deliver around 6 to 9 psi at the hose, IIRC. The arrestor would further restrict your oxygen flow to your torch as well, maybe by 1 psi. An oxycon is safer, in a couple of ways, than tanked oxygen.

[theglasszone]

Originally Posted by ICBeads

You don't need an arrestor on your oxycon. An oxycon typically contains 2 small canisters that alternate filling with oxygen at about 20 psi per canister and deliver around 6 to 9 psi at the hose, IIRC. The arrestor would further restrict your oxygen flow to your torch as well, maybe by 1 psi. An oxycon is safer, in a couple of ways, than tanked oxygen.

Agreed!

De

[NMLinda]

Quote:
Originally Posted by melabe
I just ordered a mega minor torch. When placing the order I asked about flashback arrestors and was told that I did not need one as my torch is a surface mix. ????? any feedback?

The vendor who sold me my Minor torch many years ago, before boards like this had taken off, insisted that I get flashback arrestors. They didn't seem to care where I got them, just that I got them. I had reason to be extremely greatful to them later. Even though the minor is a surface mix with less oomph than the mega minor, I somehow managed to develop a flashback in my hose. The hose stayed intact and carried the flash all the way back toward the tank. If I hadn't taken their advice, I probably would have had a bomb like the video!

This is a great thread - I'm setting up a new studio, this time with much longer hoses and multiple torches, and I greatly appreciate the information and experiences others have posted here. In addition to running my propane/oxy through my exterior walls with inside/outside gas shut-offs and black pipe, as Dale and DeAnne posted (thank you!!), I will be putting flash-back arrestors at my tanks. To minimize the risk of damaging my hoses accidentally, I will be running them under my bench. That said, I'm considering putting backer-board or metal barrier on the underside just in case I have a 'hose event'.

Finally, I bought quick connects for each torch with what I was told had internal flashback arrestors. The brand is Western, which is what my welding supply place carries, but in researching them further, it appears that what they have are actually reverse flow check-valves.

My question for folks here is, will the reverse flow check-valves act in the same or similar manner as flashback arrestors, or will I also need to add flash-backs to protect me from the torch back through the hose?

Thanks!

Linda

[theglasszone]

Hi Linda!

Sorry to hear about your "event" but I'm glad you had the forethought to use Flashback Arrestors, and even more grateful we didn't hear about your event on the Evening News (THANK GOD!!!)

I don't know personally about the difference (if any) between "flow check valves" and "flashback arrestors" so I'll hope someone with more knowledge pops in and advises... It may be they are one and the same, or have significant differences that truly matter! I'll be watching to see what's said.

Take care and good luck with the new studio! Glad your safe and Happy Holidays to you!

DeAnne in CA

[ruca]

What is the difference between a check valve and a flashback arrestor? Do I need both?
Flashback arrestors are typically constructed with a sintered filter to absorb the flame in the event of a flashback and typically have a reverse flow check valve integrated into them. The check valve is designed to prevent gases from flowing in the wrong direction which could help produce flashback. In the event that a flashback still occurs, the sintered filter on the flashback arrestor is designed to pull the heat energy away from the flame and extinguish it.

Because check valves are generally present in flashback arrestors, it is not necessary to install additional devices. In fact, doing so can cause gas flow restrictions that may lead to torch and/or tip overheating, backfires, or even a flashback.

source: http://enet.smithequipment.com/publi...%26Zoomed%3DNo

[NMLinda]

Thank you, DeAnne and Jes, for responding. Gotta give credit to the great folks at Arrow Springs, where it's due, for pushing safety and making sure I understood the importance of flashbacks. I appreciate the kind words on my new studio!

Thank you for the link, Jes, and the section you copied in your post. That was very helpful info.

Best wishes for a great holiday season to all

Linda

[cadia]

I thought the reason someone suggested FBA on my OXYCON was more to protect "IT" ( aka: my investment ) rather than a straight safety issue.

[NMLinda]

I remember seeing that advice. My first studio was set-up was for tanked 02, so I was advised to get flashbacks for both. In light of the experiences folks posted here, as well as my own, I'm glad I did! In my new studio, I'm setting up to switch between either tanked 02 (for the occasional yen to do big stuff) or an oxycon (I mostly do smaller beads). I have flashbacks for the tanked 02 side, but hadn't considered the oxycon side until I saw the advice you were given, although it conflicts with opinions posted recently, here, and in other threads.

Do you have quick-connects with reverse-flow check valves at your torch, like the ones I bought, or are you going straight from your oxycon to your torch? It may make a difference in what folks recommend to either or both of us. The reference Jes was kind enough to post seems to be more specific to the gas (ie propane) side being problematic. Now that I read it again, I guess I'm not clear whether it applies equally to the oxy side.

Linda

[ChrisCamac]

Standard quick disconnects by themselves do not have FBA's included. There are models that do have them that are known as "Safe Mates". These are made by Western and are quick disconnects with a built in FBA. You would have to research the model of quick disconnect you have or are purchasing, to know if it has the FBA's also.

[cadia]

I do not have quick disconnects.
Just the FBA's.
The more I read the more confused I am.

[theglasszone]

Cadia:

Click this link to Sundance Art Glass, and scroll about half way down the page. These are great photos of what the "Flashback Arrestors" "Quick Disconnects" and the "All-in-One" combo (Arrestors/Q Disconnects together") look like:

http://www.sundanceglass.com/gas%20equipment-r.htm

There are "Flashback Arrestors", and there are "Quick Disconnects" and then there's the "All in One" combination - which is what I have. You can order each component separately depending on your application or need, but they cannot necessarily be combined, which is why I went with the "All in One".

Hope this helps.
DeAnne in CA

[NMLinda]

Thanks for your response, Chris. The quick-connects I bought are the QDB-10's. I looked at your website and also googled safe-mate quick connects you mentioned, which got me to Western's web page. Looks like the safe-mate quick-connects are the QDB-10 thru 30 and have internal reverse-flow check valves rather than flash-back arrestors (I didn't find the latter combo anywhere on Western's webpage, at any rate). The ones you show on your website look like the QDB series, also. Is that your understanding? Based on the info that Jes sent me, perhaps the check-valve is sufficient and it's not necessary to have a true flashback in a quick-connect, at least if one is mounting it at the torch. True??

Cadia - I agree, this can be confusing. Since it appears that oxycons don't store the 02, perhaps that's why nothing is needed for them for personal safety reasons? Maybe a check-valve is sufficient for either added personal safety or investment protection? Maybe a flashback-arrestor is overkill, but if you bought already and can get enough flow to your torch, you're fine to use it?

I'm no expert in this! I hope the more knowledgeable chime in, and I certainly welcome the input.

Linda

[NMLinda]

Just saw DeAnne's post and poked in Western's web-page harder. I see that the Safe-mates are, indeed, Flashback arrestors and not just reverse-flow check-valves.

[kbinkster]

I know that this is an old thread, and maybe I should start a new one, but this thread is being discussed on another thread and there are some things that I would like to add.

Flashbacks are more likely to happen on premix torches, but they can certainly happen on surface mix torches given the right set of cirumstances. For a flashback to occur on a surface mix torch, there has to be a mix of oxygen and fuel inside one of the chambers of the torch. When it ignites, there is an explosion. Sometimes, the fire from the explosion travels upstream out of the torch and up one of the lines. It usually travels up the oxygen line.

It's important to understand how fuel and oxygen can mix inside the torch. There are at least two ways that this can happen.

The most common cause of the premixing that can cause a flashback is a leak inside the torch. If there is a leak inside the torch, gas from one chamber can enter another chamber and mix with its gas. Since we usually turn on the fuel first, it is most common for the fuel to leak into the oxygen chamber, instead of the other way around. When the torch is lighted and the oxygen turned on, there is a very loud "POP." That is the explosion inside the torch and it could continue to burn and go upstream and out of the torch. If you follow the POOP procedure (Propane, Oxygen, Oxygen, Propane) for turning on and shutting off your torch, the explosion will have happened in the oxygen chamber of your torch. This is part of the reason, I believe, that flashbacks tend to go up the oxygen line and not the fuel line.

But a leak is not the only way a flashback can occur. You can have a premix inside a surface mix torch even if there are no leaks. It is very rare that this can happen, but it can and does. If fuel somehow travels back into the torch, you can have a premix. A change in line pressures can sometimes cause this, too. Another thing to look out for is shutting off your valves all the way. If you ever turn your fuel valve off almost all the way but not quite all the way, a tiny stream of fuel will still bleed out of the torch. Sometimes, it finds its way back into the torch, going up in through the oxygen ports. If it does this, then it can pool inside the oxygen chamber of the torch and when you go to light up, you will have fuel in the oxygen chamber and this will cause a premix and possible flashback.

How do you know if the premix was caused by a leak or by the fuel bleeding back into the torch? Well, if it is a leak, it will happen repeatedly. If it never happened before, and has not happened since, then, the premix was likely caused by not turning the fuel off completely.

So, what about the role of flashback arrestors(FBAs)? Well, where ever the FBA is installed, that is where the FB will be stopped. If the FBAs are installed at the torch, that would keep the flashback from traveling further up the lines to the source of the oxygen (most likely path) and fuel (less likely, but I guess still possible). Some people insist on putting the FBAs at the regulators for added protection against line failure, but I don't agree with this.

The way that I understand FBAs to work is that the explosion from the premix that causes the flashback triggers the valve in the FBA to close. It's the pressure change (the burst from the explosion) that triggers the FBA to shut. If you burn through a line, the pressure actually drops in the line and the gas still flows. Unless you have a FBA that has the added feature of closing due to overheating, the FBA valve will not be triggered shut and it will do you no good.

[bshelle]

Kimberly, thank you for that information; it is very helpful!

What imput do you have regarding oxycons & flashbacks?