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Boiler T&P drain dischrging into glycol tank

retire09

Silver Member
Joined
Feb 19, 2010
Messages
365
Location
Alaska
I have a boiler installation where the drain line from the T&P valve is running into a glycol tank for recirculation back into the heating system.

I have asked for something from the manufacturer or mechanical engineer to support this installation but have nothing yet.

Is this allowed?
 
retire09 said:
I have a boiler installation where the drain line from the T&P valve is running into a glycol tank for recirculation back into the heating system.I have asked for something from the manufacturer or mechanical engineer to support this installation but have nothing yet.

Is this allowed?
As stated not an issue provided there is an airgap
 
Why would an air gap be needed when it is glycol in the tank and glycol discharging from the T&P?

Is the air gap for other than backflow prevention?
 
retire09 said:
Why would an air gap be needed when it is glycol in the tank and glycol discharging from the T&P?Is the air gap for other than backflow prevention?
The TP is a safety device and should not relieve unless there is a performance issue with the boiler. The air gap would allow a visual that there is a safety issue with the boiler.
 
The air gap is also required to ensure a safe release of pressure. If the tank happened to fill, and the extension was submerged, there would be a restriction in the flow. Also - long term submersion could clog the end of the extension. Keep the end of the T&P free from obstruction, and for viewing as Gregg mentioned.
 
If the boiler T&P was to discharge would there be enough capacity in the glycol tank?

Could the T&P discharge tube ever be below the glycol level in the tank?

pc1
 
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