Why SPGs got dirt inside ?

[emoreira]

I've seen lots of SPGs that got dirt inside, full functional, no water inside, but making them useless as they cannot be read.
SPGs are bourdon type manometer, so the air that comes from the tank goes to a closed bended tube inside. The interior of the SPG is also sealed to the environment.
So, where does the dirt comes ?

 

[350xfire]

Check the inside of your tanks... May be bad filters on the compressor system.

 

[emoreira]

Check the inside of your tanks... May be bad filters on the compressor system.

No, that would mean that the bourdon tube is leaking, and the SPG should also be leaking, which I've not seen. Besides tha SPG is used in many tanks filled by different compressor in different operators.

 

[johndiver999]

I think the external case is compromising and water gets in there causes corrosion and also leaves salt and mineral deposits.

 

[Belzelbub]

In the two gauge picture, I don't think it's dirt. Looks more like the lens is getting hazy. Similar to how car headlights get foggy.

The other one could be dirt or other contaminants. I'm sure these are not put together in a cleanroom, so this could happen. The first picture looks fairly old, so I'm assuming lots of movement over the years, which can grind down small particles that eventually attach to the most attractive surface.

 

[2stroketony]

The first definitely looks like water infiltration. The second could be a film of some kind of hazing of the plastic.

 

[Scared Silly]

Water infiltration ... the single one looks like fungus.

 

[Jimchris]

Picture 1 is a spg with a plastic lens and an o-ring seal, and the case is simply crimped around the lens to hold things in place, With use and expansion/contraction its not hard to see how water/corrosion could sneak in.

 

[rjack321]

Picture 1 is a spg with a plastic lens and an o-ring seal, and the case is simply crimped around the lens to hold things in place, With use and expansion/contraction its not hard to see how water/corrosion could sneak in.

not only that but the oring sealing surface is dented in multiple places.
This is corrosion from water/moisture getting under the lens.

 

[johndiver999]

not only that but the oring sealing surface is dented in multiple places.
This is corrosion from water/moisture getting under the lens.

yeah but rubber boots on spg are sooooo uncoool.. with all the cool kids..