Shower flow?

[Dannyparty92]

Just read installation manual for an electric shower and it says "minimum static pressure 0.5 for flow valve to stay closed" if the pressure was 0.5 bar or below why would this cause the flow valve to open? Thank you.

 

[PlumbBobBob]

i think it means it needs a minimum of 0.5 bar to hold the flow valve closed? although i stand to be corrected

 

[Dannyparty92]

But is the flow was below 0.5 bar why would this cause the valve to open?

 

[PlumbBobBob]

perhaps the pressure holds the valve shut like a door. if someone is leaning on a door it is difficult to open it from the other side.