Green Verdigris on PRV

[techweb]

Hi,

I have a PRV located in a heated plant room that is between a pair of stop cocks. It was installed to keep pressure under 3 Bar a couple of years ago but I have noticed an area of verdigris on the piece from the main body to the gauge. I wondered if this might be sign of a leak / trouble or possibly just condensation that might occur when very cold mains water comes in through a warm plant room.

It's not wet to touch and no evidence of drips as there is in fact cardboard below so it would show up.

If it needs attention, I best get it replaced.

Thanks in advance.

 

[ShaunCorbs]

That’s normal just porous brass

 

[techweb]

That’s normal just porous brass

Thank you… So what causes it out of interest?

 

[ShaunCorbs]

Thank you… So what causes it out of interest?

Cheap brass normally

 

[techweb]

Cheap brass normally

So is it water / condensation on the outside that has caused it? From what you’ve said it doesn’t pose a leak risk and I should stop being paranoid.

 

[gmartine]

Brass is mainly copper so it can behave like that, maybe it was a temporary drip, leak or a blob of dripping flux either way it looks secure. Clean it off with a scouring pad or wire wool and keep an eye on it if it really bothers you.

 

[techweb]

Brass is mainly copper so it can behave like that, maybe it was a temporary drip, leak or a blob of dripping flux either way it looks secure. Clean it off with a scouring pad or wire wool and keep an eye on it if it really bothers you.

Thanks… Cosmetically it’s no issue to me. I was concerned that it was a sign of the fitting rotting / corroding to a point where a leak maybe imminent. That’s clearly not the case so I will leave it be.

 

[ShaunCorbs]

So is it water / condensation on the outside that has caused it? From what you’ve said it doesn’t pose a leak risk and I should stop being paranoid.

It’s water leaching through the brass

 

[Basher]

If the water in the pipe is from an unvented closed circuit (eg heating system) it should be fine, especially if there is inhibitor in it.
If from a fresh water supply being replenished from the mains (eg containing chlorine) there's a very slim chance there could ultimately be an issue.
The two most common mechanisms that cause faults in brass are stress cracking - where stresses in a casting introduced during manufacture cause cracks to open up (I suggest unlikely with these fittings) - and the other is "de-zincification" due to the chlorine in the water reacting with the zinc in the brass and causing voids to be 'eaten away' in the casting. Both symptomatic of poor manufacturing techniques.

I wouldn't worry that the fitting is suddenly going to disintegrate or leak majorly, but possibly worth keeping an eye long term!

 

[techweb]

If the water in the pipe is from an unvented closed circuit (eg heating system) it should be fine, especially if there is inhibitor in it.
If from a fresh water supply being replenished from the mains (eg containing chlorine) there's a very slim chance there could ultimately be an issue.
The two most common mechanisms that cause faults in brass are stress cracking - where stresses in a casting introduced during manufacture cause cracks to open up (I suggest unlikely with these fittings) - and the other is "de-zincification" due to the chlorine in the water reacting with the zinc in the brass and causing voids to be 'eaten away' in the casting. Both symptomatic of poor manufacturing techniques.

I wouldn't worry that the fitting is suddenly going to disintegrate or leak majorly, but possibly worth keeping an eye long term!

Thank you. It’s on the mains supply to the house. I had it put it when they were having spikes in pressure in our area so as to protect any potential issues internally. I could just get it taken out as it’s not required any longer. I guess it’s just another point of failure if left in place.

Good to know it’s unlikely to fail catastrophically.