SB-912-039 and SB-914-025.
3.1.2 Option 1) 1 mm enlarged to 2.5 mm vent hole. Simple/easy/no additional weight/cost or complexity.
3.1.3 Option 2) Add nipple & hose, to Option 1) Looks good. Adds little to function. Adds cost & weight.Feel good factor?
If your correctly installed expansion tank is overflowing, you have a serious problem, that far exceeds any mess that may result.
As a matter or urgency address the cause of the overflow.😈
