Concerned About Viking Blowing Off

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caper1175
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Post by caper1175 » Tue. Jan. 27, 2009 2:24 pm

Hi all - I have a Viking Jr. boiler and have a question or 2.

There is a pressure/temperature gauge located near the front of the top of the boiler. My circulator opens at 180 and when I have a good fire going the temperature can go to 210+, at which time I ususally panick and close the draft completely for fear of it blowing off. Am worrying too much or can it blow off if the temperature gets to high? It hasn't happened to me but I'm always fearful that it will.

Thanks,
Jason.

 
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coaledsweat
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Post by coaledsweat » Tue. Jan. 27, 2009 2:39 pm

The pressure relief works on pressure not temperature, I have seen temps @ 300* without a relief valve blow off on my boiler.
The pressure/temperature gauge itself (it is called a triadicator) can take at least 100# of pressure and significantly higher temps than your system. If your temps are under 250*, you should have nothing to worry about as long as the pressure is normal.

 
caper1175
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Post by caper1175 » Tue. Jan. 27, 2009 6:37 pm

Thanks for the reply....my pressure stays pretty constant staying between 15 and 20 psi.


 
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Freddy
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Post by Freddy » Tue. Jan. 27, 2009 8:50 pm

Lot's of gauges aren't that accurate. If it actually got to around 250 it might blow, but I'd say no worries below 230 at 15 PSI. I start to get nervous above 230. Make sure the pressure relief is piped so it's pointing at the floor!

 
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coaledsweat
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Post by coaledsweat » Tue. Jan. 27, 2009 9:17 pm

The worst time I remember was when the temperature needle was actually showing 40# in the pressure scale, I estimate that to be around 330*. The pressure was at 28# and it didn't vent a drop. Like Freddy said, the gauges are not real accurate, neither is the setting on the PRV.
At work I have 2, 2" PRV safety valves on the boiler that are set to pop at 150#, they are changed yearly, cleaned and recalibrated. One time I was looking for a leak so I filled it to the top with water and ran the pressure up with the feed pump. When it got to 230# I was shocked, they never spilled a drop. I talked with the Factory Mutual inspector about it and he was not the least bit surprised. :shock:
Oh yeah, at 150# we pipe the vent through the roof, not to the floor. ;)

 
caper1175
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Post by caper1175 » Tue. Jan. 27, 2009 9:28 pm

Freddy wrote:Lot's of gauges aren't that accurate. If it actually got to around 250 it might blow, but I'd say no worries below 230 at 15 PSI. I start to get nervous above 230. Make sure the pressure relief is piped so it's pointing at the floor!
My pressure relief shoots through my foundation into my driveway. Is this OK? That's the way it was when I bought the house so I just left it.


 
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coaledsweat
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Post by coaledsweat » Tue. Jan. 27, 2009 9:36 pm

You just want to make sure it will not spray anyone with hot water/vapor when it pops. If it runs uphill at all, the vent should have a small drain at the lowest point to keep it clear, you don't want ice blocking it.

 
caper1175
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Post by caper1175 » Wed. Jan. 28, 2009 9:43 am

coaledsweat wrote:You just want to make sure it will not spray anyone with hot water/vapor when it pops. If it runs uphill at all, the vent should have a small drain at the lowest point to keep it clear, you don't want ice blocking it.
Once it goes out throught the foundation it points down towards the ground, so I should be good. I always make sure snow is not blocking it when I'm clearing my steps.

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