Megoflo has no tundish!

[Gas man 101]

The main purpose of the tundish is to allow a secondary means of relief in the event the d2 becomes blocked (eg it could freeze up if it is discharging slowly in winter).

I may be wrong but i have just take my unvented course around 2 months ago, A question came up asking what the reason for a tundish is for and should it be fitted. The answer was a tundish should always be fitted, for the main reason that the prv and tprv can be seen when discharge as if the d2 runs into a drain there is no way of telling if it is dischargeing, and the 2nd reason is it reduces the mains pressure down to a lower pressure, and gravity takes over, and opens it to atmosphere and cools down the water as you dont want 90 to 95 water dischargeing down a wall or down a drai. I got 100% so it musta been right

 

[AWheating]

the 2nd reason was to turn mains 3.5bar usualy from pressure to lower pressure gravity and atmospheric to reduce the temp and pressure to discharge safley. I got 100% so it musta been right

what?

 

[Gas man 101]

It reduces the mains pressure down to a lower pressure, and gravity takes over, and opens it to atmosphere and cools down the water as you dont want 90 to 95 water dischargeing down a wall or down a drain. Maybe worded incorrectly. But its what my unvented book states.

 

[AWheating]

oh, ok i understand it now.
I guess these reason's are just a nice byproduct of the tundish design, but its not going to decrease the temp a great deal especially if its a short run. more important to position the terminal correctly.

 

[Gas man 101]

When i read back it made no sence, was filling out my acs evidence at the same time, Im only going on what my unvented book BPEC says , and thats one of the reason in the book and test so thought i would share the reason that they had given. I dont know about temp if your putting it to the atmosphere and lowering the pressure in turn would reduce the temp, but the main reason would be so see when the safety valves are dischargeing.

 

[GrahamM]

It reduces the mains pressure down to a lower pressure, and gravity takes over, and opens it to atmosphere and cools down the water as you dont want 90 to 95 water dischargeing down a wall or down a drain. Maybe worded incorrectly. But its what my unvented book states.

I think I know what you mean. It provides an air relief so that it reduces the pressure(pull) in the D2 pipe allowing the discharge to run more freely. It will not reduce the temp. to any degree though. If the D2 pipe run is quite short and the T&P valve blows off at 95°C it is still going to terminate at maybe 80-90°C.
As said it also provides a visual means of identifying an issue and in the eventuality the D2 pipe becomes blocked it allows secondary means of releasing the discharge.
Who would have thought that little bit of plastic would have so many uses!