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Hi all,
Been looking at my robot and I don€™t have space to screw a relief valve into my reg (robots to small:sad:) and I considered this idea and didn€™t know if it was legal:
Would it be legal for me to unscrew the burst disc from my fire extinguisher and put a relief valve in its place? So the relief is constantly attached to my bottle? Just a thought...
Dave moulds
Team Turbine
Dave,
I strongly suggest you leave the burst disc in the extinguisher alone. Replacing the 190 bar with a 1000 psi relief valve is not wise, you could get the CO2 venting from the extinguisher on a warm day / in the car etc. There are other reasons why this is also not a good idea at all.
Paul
FRA Technical Team
cant you put the valve somewhere else on the HP pipe? assuming your still using the reg i made, the compression fitting on the reg and Co2 bit both have 1/8threads. why not one remove one of the compression fittings and put in a t piece and a 1/8 to 1/4 fitting.
Oh ok Paul, Ill leave It be :)
Yes, im still using the reg I got from you Alan...But space inside the robot wont allow me to put it in the reg
Guess ill have to make a fitting or somthing..
Do featherweights even need a relief valves yet?
Dave moulds
Team Turbine
YES!
High and low pressure.
Mr Stu
*sigh* why are LP rels really nessasairy!? I carnt see a surge of pressure going into the lp side of a setup and even if it did happen whats the worst that could happen?....A pipe comes out of a pneumatic push-fit, Am I missing the point?
Dave moulds
Team Turbine
what happens if the regulator blows and lets 1000psi into the system? BANG!
well.. thats why Dave suggested the fire extinguisher.. so if that does happen Alan, Daves got backups! *giggles*
*pats Dave on the shoulder for being so concerned about safety* :D
Ah, I see what you mean Alan....
Yes Audrey....tis like the oposite of fight fire with fire or sumit :)...
Dave moulds
Team Turbine
Dave, yes you are missing the point. This subject has been discussed on this very forum before. Perhaps you could advise me at what pressure a push-fit will fail.
Ok guys - I get the point now:sad:..
Isnt it somthing like...a 10bar pushfit will blow at 15bar? and a 12bar at 18bar etc...
Dave moulds
Team Turbine
stop picking on him you lot!!!! grrrrr!!
so hes forgotten summut and just need help, is it a crime? sheesh, you lot act like hes some kind of idiot, gawd.. that gets me so mad!!!!
He needs a lil help, the least you can do is to help him, its not like one of you remember everything is it?
Audrey, not that I need to explain myself to you, I have a lot of time for Dave and Im sure he knows it.
Thanks Paul, I know you have time for me, but I feel your comment about advise me on the push fits was harsh and sarcastic. I was not aiming any of my comments to ignore your comments, as I know you may have more knowledge on pneuamtics than I.
Thanks and sorry.
Dave moulds
Team Turbine
P.s. Thanks for your outburst of randomness Audrey :)
Dave, the question was not intended to be sarcastic and apologies if it came across that way. It was intended to encourage you to think through your argument rather than just be told no, do as you are told (which was in my opinion the Mentorn way).
Paul
I like discussions like this. Learning all the time.
Pauls got a good point about explaining your argument (and health and safety is pretty damn serious).
See http://www.fightingrobots.co.uk/discus/messages/9/1332.html?1077738986http://www.fightingrobots.co.uk/disc...tml?1077738986 for a more detailed explanation but in summary:
A failure mode of a regulator is to let by, thus pressurising the downstream low pressure components to full bottle pressure. This can be caused by foreign matter on the seat, a seat failure, scored seat etc. There are numerous manufacturers and types of pushfits, it would not be possible with any degree of confidence state at what over-pressure they will fail at. I have tested an 18 bar pushfit at 50 bar without failure. So, lets assume M2 has a regulator failure, the LP side pressure rises to 50 bar and the pneumatic system does not fail, I then fire the ram and no doubt a big bang as the ram explodes from mechanical failure. This is why M2 has always had a LP relief valve from day 1.
Another reason for the LP relief valve is to avoid the need for test pressure points. How does the tech checker know what pressure you are operating at? Simply by checking the LP relief valve certification.
Hope that helps explain some of the thinking behind the LP relief valve.
Paul
Ah ha!....when you put it that way id best get 1 :)
Dave moulds
Team Turbine
sorry for the miss-understandings
Paul, as Dave had said, it did sound harsh and sarky, thats the only reason I was defending him, and sheesh... lighten up... :sad:
everybody knows about safety and other things, he was asking to verify what he wasnt sure about... as I dont know owt about bots NOR really give a monkey about, dont start lecturing me about whatevers ;) because I DONT CARE! :)
as I dont know owt about bots NOR really give a monkey about, dont start lecturing me about whatevers ;) because I DONT CARE!
Audrey, is there something else you could be doing then?
[Original comment removed, on the grounds that I might accidentally have caused offence.]
What could possibly be more fun than winding up roboteers? (Hmm, wind up roboteers... new category.)
Besides, I strongly suspect Audreys picked up quite a lot, in her time.
--
Fluppet
lighten up, no thanks Audrey but thank you for your concern.
Paul
People the small row has endid. I think it would be a nice idea if this thread could be deleted but I dont have controll over that - Audrey I have nothing against Paul.
Dave moulds
Team Turbine
Dont delete the thread - its useful information, and Dave asked a valid question. If we delete every thread where someone has said something which could be taken the wrong way, this forum would be a lot smaller (and less helpful). Hopefully everyone involved is sufficiently mollified that these posts wont cause further offence.
I should also apologise - in retrospect, my above post was unhelpful. I was trying to make light of the situation, realised what Id said could be taken the wrong way by third parties, removed it, left the note in case anyone had read the old version, and only just realised that the note made it sound as though Id had a rant at someone (which I hadnt). Teach me to stick my nose in on a thread with which I have nothing to do (although, since I have pneumatics plans, this is a useful thread to me.)
Time to duck out before I make matters worse, again.
--
Fluppet
hmmm, this thread sure got depressing quickly....On a happy(?) note this is my 100th post in the furom :)
Dave moulds
Team Turbine
Just trying to lighten the mood :)
Well done dave, LOL.
These threads are helpfull to people like me who read around, gives you a wider range of knowldge and reminds you of past forgotten threads.
SUrely you cant maon at someone if they havnt noticed this topic before.
Oh and btw, im not at all moaning at ypu Paul, or anyone else on this thread, just a general thing for everyone to realise.
Grant
WAHEY!!! good on ya Dave!! :)
What about if the fire valve is not in the bottle but is part of the valve system to fire the ram ? ( the old fire valve HP type system) would it be ok then ?
Omigod. Back on topic! Big hand, Simon. :-)
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Fluppet
I think that the H&SE people would get very upset if there was an accident caused or exacerbated by the lack of a standard bursting disc on a fire extinguisher bottle.
This accident could happen anywhere, at an event, during transport in your car or at your home.
Such an accident would undoubtedly not be covered by the either the event or your car insurance.
The busting disc is fitted to gas storage cylinders so that they don€™t explode when in a fire and kill anybody, like Firemen.
I dont have a copy to hand, but IIRC the RW rules always insisted in a bursting disc being fitted to all valves screwed into a fire extinguisher bottle for use in robots as well as the 1000 psi valve.
The LP side MUST have a safety relief fitted.
If a LP pipe or fitting bursts due to over pressure then the loose pipe will flail about and may well hit you in the face like a whip.
Its your face so fit YOUR LP safety valve.
I will not let robots into my event without both the standard bottle valve bursting discs and LP relief valves.
IIRC the RW 1000-psi relief valve was brought in to meet the demands of the Stage Hands Union, which forbade them to work on gas pressures over 1000 psi.
As we don€™t have stagehands belonging to a union, the H&SE requirement for a bursting disc is adequate for my Yeovil Robots-at-War, I don€™t require the 1000 psi valve to be fitted as well.
Dave, best leave the disc alone and try to fit the relief valves in somewhere, and save face that way.
I was frustrated by having to fit a 1000 psi PRV when all of the HP components on M2 were rated at over 230 bar for RW. Yet RW never asked for a LP PRV!!
The 1000 psi valve was retained in the rules for a number of reasons:
1. To comply with the Mentorn rules although this may now be history.
2. To ensure no competitors gained an unfair advantage by boosting their pressure by force heating the bottle before a fight.
3. To allow a safety margin for machines using non-certified (for pneumatic use) hydraulic parts.
4. To avoid the need for a pressure test point.
Im sure I thought of other reasons when writing the pneumatic rules.
It is pleasing to hear of your support for LP PRVs Roger.
Paul
I support all sensible and necessary safety rules that are required by the H&SE and insurers.
I have my own reasons for casting doubts on €œextra€ rules applied by other organisations, especially when they are applied at the roboteers expense.
I never did agree with Mentorn€™s €œextra€ CO2 safety rules, such as 1000 psi SRVs, neither did Rex Garrod.
Im not sure anyone answered my question there :)
Chaos 2 uses a system like that so at a guess I would say yes but I am not sure.
Regards
Ian
Simon, if your gas bottle is not fitted with the original valve or an approved replacement, i.e. a hand wheel type, it probably does not comply with the current H&SE regs governing its use.
The bursting disc should be fitted to the bottle neck valve and connected to it internally upstream of the valve mechanism.
That way it is effective even when the bottle valve is shut off.
If you have a bursting disc fitted to a valve downstream of the main valve it will not be effective as required.
In my opinion it would not be OK as you asked.
I would not allow it at my Yeovil event.
At an FRA event it would be up to their safety technicians as to whether it would be OK or not.
My appoligies Simon I read your post all wrong. I thought you ment using the Squeese type handels to fire your ram. Thats fine but i dont think what you want to do is.
Regards
Ian
Simon, I have to say I do not understand what you are trying to do. Fire valve in bottle? Is this some sort of valve used in fire supression systems?
Paul
FRA Technical Team
Probably my explanation. Im using two fire extingusher valves to fire and empty my ram.
My question was would it be ok to fit the relief valve into one of these where the burst disk normally goes. I dont intend to mess with the one fitted to the bottle.
I believe I understand now, as long as the CO2 storage bottle still has the rupture disc fitted as you state then the question only relates to the position of the 1000 psi valve. Assuming you have one valve with its inlet connected via a pipe to the CO2 bottle, then this one can have the 1000 psi PRV fitted in place of the rupture disc. The other valve which you are using to exhaust cannot be used for the PRV. IF you modify the valves in anyway that may affect their pressure integrity, they will require re-certifying. Hope that helps.
Paul
FRA Technical Team
Am I wrong when I understand by reading the above that Simon wants to keep the rupture discs on the bottle valves themselves in place but wants to replace one on a seperate valve ? I am getting confused here.