Glycerin pressure gauge blows

[PineRidge]

In the process of searching for information regarding PTO driven boom sprayers on the Internet I ran into an interesting story about a chap that built one and told his tale (in part). Did any of you guys that are more familiar with glycerin filled pressure gauges ever hear of such a thing, think it's at all possible?

Interesting story about the gauge... When I first tested this unit I ran the pressure low and slowly increased it. I was looking back at the pump when bang! Something exploded! I thought a hose came off. Something hit me in the side of the face. The pressure gauge which was level with my head had blew out the glass. The glass and the glycerin were all over my face. I only opened one eye since I could feel glycerin over the other. I looked down and blood was dripping into my hand. I thought wow, I must be pretty bad. I shut off the tractor and walked to the house. I stopped in the garage and decided to look in the car mirror so I could tell how my wife would react. I had only one time little cut on my nose! The glycerin had made it seem like I was bleeding much more and with the pain of the impact I thought I had serious damage! Got lucky! The gauge exploded because I neglected to remove the tiny little plug tip on the top that you are supposed to cut off. I installed the gauge several months before testing and figured I'd cut it later in case I had to tip the unit over.

 

[SkyPup]

Never heard of that before, I've got three glycerin filled pressure gauges online to my tractor hydraulics and the logsplitter ram and have never had that problem. They normally operate around 2,500-3,000psi but are maxxed out at 5,000psi, but even with pressure spikes have never had that occur.

 

[slowrev]

the glycerine gauge has to be vented ??? I would think the glycerine would dry out if that happened.
Ben

 

[jinman]

Mike, the glycerin in the gage is just a damper for the needle as I understand it. It's not under any pressure. If that happened to the fellow, I think he had a faulty gage to begin with that leaked pressure into the meter face.

 

[5030]

That guy is smoking something illegal. First off, the little rubber plug on the top is where the glycerin is added to a dry guage and the main reason for using a filled guage is the glycerin absorbs the pressure spikes much like an inline snubber. I suspect his Burdon (sic) tube ruptured and detonated the guage.

 

[PineRidge]

That guy is smoking something illegal. First off, the little rubber plug on the top is where the glycerin is added to a dry gauge and the main reason for using a filled gauge is the glycerin absorbs the pressure spikes much like an inline snubber. I suspect his Burdon (sic) tube ruptured and detonated the guage.

I also suspected that the plug was for adding additional glycerin. I would think that if the plug had to be removed there would be a warning on each gauge. My bet is that he had an internal defect also, but still scary if it actually happened.

 

[frank_f15]

Mike, i have used pressure gauges of all type including Glycerin filled. the only reason for the Glycerin is to dampen any spikes or severe vibrations. His problem was a bad gauge, even if you over pressure a gauge, it will just ruin the gauge not blow it up unless you expose it to extreme pressure above its design.

 

[Ford960]

I agree with you guys that this is not normal and not something to raise a red flag over.
We used a lot of these gauges in the fire truck industry and never heard of one failing like this. In fact, if the fluid leaked out of a gauge then we didn't replace or repair/refill it as the operation of the gauge remained unaffected, besides most firefighters weren't concerned with pulsations in the gauge needle anyway.

 

[_RaT_]

It is typical to "vent" the glycerin gauge to the atmospheric pressure you are at. While the pressure changes little back in the Mid West and the East, out West, you can go as low as 200 minus feet below sea level to 14,500' above sea level. Very few folks live at either extreme, but lots in between.

PS- We also have high altitude ciooking instructions when at 6000' and above. Water boils much sooner but is not nearly as hot.

 

[markct]

thats what happens when a gauge tube blows out, can happen on a filled gauge or a dry gauge. basicly the tube inside blows then of course it pressurizes the case which was never meant to be pressurized and thats the result, saw it happen to a truck air gauge once. thats the reason they tell you to stand not directly in front of oxy acetylene gauges when opening the tank valves