Non return valve for in board tank?

Surfer
Surfer Club Member Posts: 1,303
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edited April 2014 in Caravans #1

We have a 2011 Lunar Delta TI with an inboard tank.  We end to fit a non return push pull valve between the pressure switch and inboard tank.

there is an arrow on the connection.  Which way should this be pointing to build up pressure in the in board tank allowing the pump to turn off when the tank is full?