Tiny droplet of moisture in SPG

[Centrals]

Are you sure it is water and NOT oil?
The bore of the HP hose is pretty tiny so it is quite difficult for water to pass through it without extra help. However, if there is already water/moisture in the 1st stage then anything is possible when the tank is turn on.

 

[grf88]

If it is registering pressure then the water did not enter via the first stage as the bourdon tube would have to rupture to allow water to enter the inside of the case through that route. The water probably entered between the glass and the casing or through the pressure relief plug (safety device). If it is fresh water the gauge could last a while before it fails but if salt it will probably have internal corrosion fairly quickly. If the face can be removed and the internals dried out and then resealed it may be OK but many or most cannot be opened.

 

[grf88]

Bourdon tube pressure gauge - WIKA Canada

 

[caruso]

Even if you didn't make the classic mistake of putting the dust cover on the second stage regulators before dunking them in a rinse bucket, if you don't make it tight, you might not have gotten a good seal and water could have gotten into the first stage that way. The hard plastic dust covers don't always seat well unless you center them perfectly and give the tightening screw a good hard twist.

Also if you've got a regulator in place of your auto inflator on your BCD that regulator must be capped before dunking the BCD in the rinse tank or you're going to have the same issue.

 

[KeithG]

If it is registering pressure then the water did not enter via the first stage as the bourdon tube would have to rupture to allow water to enter the inside of the case through that route. The water probably entered between the glass and the casing or through the pressure relief plug (safety device). If it is fresh water the gauge could last a while before it fails but if salt it will probably have internal corrosion fairly quickly. If the face can be removed and the internals dried out and then resealed it may be OK but many or most cannot be opened.

Agreed! Lots of people think the SPG housing holds 3000psi of pressure. It does not. That is not how they are made.

Water that gets into your SPG from the first stage is trapped inside the Bourdon tube hidden behind the face plate. You can not see the tube, nor can you see inside the tube. You can only see the type of water once the tube ruptures. At that point your SPG no longer works.

If your SPG works and has water in it, then it came in through the casing. Most likely via a failing pressure relief valve on the back of the gauge.

 

[Scared Silly]

The above is spot on. Water in the SPG means the case has a leak. If water came from the first stage the Bourdon is busted and the gauge would not work. As stated, a failing pressure relief valve on the back of the gauge is more than likely the culprit. At some point the dial with become corroded and not work properly.