Little Giant Took A Dump

[Jim Morrison]

We were using the LG in 14 degree weather. It was sitting outside the van for about 10 min with the pilot light on. It was then turned on and we went inside to start a t&g job. When we came back outside there was steam pouring out the chimney and a big puddle of water underneath it.

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I don't have a pressure relief valve hooked up (yes I know this isn't right) Just trying to figure out if the cold played a role in this or if it was just pressure?
And most important, can this be welded?

 

[Mike Draper]

could have been both, in the past it could have semi-froze and caused the coil to weaken. Other factors could come in to play as well. Is the clutch on your pump in perfect working order? If you turn the clutch off does it continue to turn even just a little? This could possibly cause pressure build up and a rupture. other factors depend on how your machine cycles the water. What we do know is that you need to get a pressure relief valve, that would have probably saved this expensive repair and down time. I doubt that can be welded.

 

[Charlie Lyman]

Does the little giant not come with a pressure relief valve?

 

[AshleyMckendree]

Just went through this with my 3ht (Hydramaster copy from the 80's)
We had our machine set at 1200psi for T&G, hooked it up and after 10 minutes this happened. We took a peice of wood and a hammer and closed the mouth it created, then built it up with 15% Silver Braze. Using an Oxy/Ace setup.

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We have ran it up to 800PSI at max temp (We get up to 260 ATW if we are not careful) and it doesnt leak a bit.

 

[Royal Man]

They are only rated fro 800 PSI. If you want to go 1200 PSI. Have the pump after the heater. The other dilemma is that pumps last longer with cold water going into them.

 

[Shawn Forsythe]

When a heat exchanger splits open due to over-pressurization, a good portion of the header and exchanger pipe is often affected as it swells under pressure, thinning the malleable copper. At the point of failure, the weakest part bursts open. Even if you were somehow able to repair the burst section, there will be a good portion of the remaining tubing which will be highly compromised, and unable to withstand rated pressures. Usually with a catastrophic burst section (not a pinhole), the usual remedy is coil replacement. Yes, there are exceptions, and it is a road you may opt to take.

The little Giant heater does NOT come with a pressure relief valve, but is sold as a separate accessory by Little Giant and thier distributors. It is a mandatory device, where you have the remote possibility of flow disruption through the heater. This is because any flow disruption while the heater is running can result in an extreme pressure spike caused by vapor pressure of the heated water.

The LG heater is designed to be used after the pump. Hence, it's rated pressure capability. LG does make a 1000 PSI working/1200 psi test pressure coil as an option. Still, a relief valve is always necessary. Using the heater before the pump means that you would have to operate at very low temperatures (less than 180 deg F, dependent on head pressure available), to avoid pump cavitation, which will destroy the pump even before the heat can.

 

[Jim Morrison]

Does the little giant not come with a pressure relief valve?

Ya its sitting on a shelf in the shop.

I have a friend who is a welder, will get him to have a look, if he can fix it we will just use it to clean restaurant carpet for now.

When a heat exchanger splits open due to over-pressurization, a good portion of the header and exchanger pipe is often affected as it swells under pressure, thinning the malleable copper.

The distortion is visible on the back side of the pipe where it failed, we will give it a shot and keep our fingers crossed.

Thanks for the replies

 

[Royal Man]

Just use silver solder. If you need to find some one to fix it locally. From my experience the radiator shops don't have a clue. But, The heating and air guys use silver solder on a regular basis.

 

[Shane T]

I friend used material from an irreparable coil and patched a split like that. Silvaloy and acetylene torch. That said he does not exceed 600psi.

 

[dealtimeman]

Only silver solder - sand and clean the area well. Flatten the lifted material as close to original. You can patch but after you have used the silver solder. Must contain something like something 15% silver content.

 

[AshleyMckendree]

Also, an HVAC or refrigeration guy will usually GIVE you a few sticks of 15%, as they charge each job for new packages, and usually only use a few out of the entire batch to finish the job, and have tons left over.

A tube of this stuff runs $150+ and you will only use 2/3 of a stick, and that's most of it being wasted while you practice.

 

[Shawn Forsythe]

Little Giant uses "Harris Stay-Silv 15" to join the tubing, which is coincidentally 15%, but to be sure you have the same melt point as the original,you should aim for the Harris stuff if you can.

 

[tmdry]

Same thing happened to mine almost 2 months ago, I've been cleaning w/ cold water and the 360i and have not seen any difference in the cleaning ability. I also didn't want to spend $2400 on a new little giant nor over a grand in parts, labor, fuel, time. So far so good, I'll eventually figure out the heat situation but I haven't had any trouble.

 

[floorguy]

Same thing happened to mine almost 2 months ago, I've been cleaning w/ cold water and the 360i and have not seen any difference in the cleaning ability. I also didn't want to spend $2400 on a new little giant nor over a grand in parts, labor, fuel, time. So far so good, I'll eventually figure out the heat situation but I haven't had any trouble.

OHHHHH BULLSHIT!!!!!

my ignitor went out and took a week to get a new one here and put in....

AND i even have the little bit of heat from the heli-coil....

and i can tell you now....HUGE DIFFERENCE.....between heat and no heat....

granted these are on moderate to nasty jobs.....the not so dirty ones...no issue

but dont tell me there isnt....i have been there

 

[John Olson]

I have a couple of 2HT and 3HT little Giants here. they aren't the prettiest but they have been tested and work. Haven't been advertising them for sale as I prefer to hold on to them until someone I know needs them as used ones are hard to come by. If you in a Jam I am sure we cna work out a fair price to ship one to you.

 

[Jim Morrison]

Does it matter if it is an oxy-acetelene or a acetylene-air torch?

 

[Shane T]

Never heard the term "acetylene- air". Probably just a Canuk term for oxy-acetylene.

 

[Jim Morrison]

A simple acetylene torch uses air rather than oxygen, the flame it produces isn't as hot as oxy-acetylene. One of its uses is to solder lead.

 

[AshleyMckendree]

I prefer oxy-ace for this type of work, much more control. But it can be done with an ace-air torch, they are just expensive.... Although that investment is made back from not buying the oxy constantly.

 

[tmdry]

OHHHHH BULLSHIT!!!!!

my ignitor went out and took a week to get a new one here and put in....

AND i even have the little bit of heat from the heli-coil....

and i can tell you now....HUGE DIFFERENCE.....between heat and no heat....

granted these are on moderate to nasty jobs.....the not so dirty ones...no issue

but dont tell me there isnt....i have been there

I don't bullshit, I tell it how it is

For instance, I don't do nasty jobs - I don't get those clients. My clients are all low to moderate soil.

Use either S/O or SG depending on soil level.

As you mentioned "no issues" w/ the difference.

But if I was doing nasty ones I would go w/ the diesel heater and ditch the little giant overpriced setup all together. I've spend way more money fixing up the little giant and all it's components than the coils blows up on me. What a pain in the ass.

 

[Jim Morrison]

This is what I found on the shelf, does this look like a pressure relief valve for a LG?

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[floorguy]

yup i think so