I will attempt to describe how to remove, fettle and replace the "Screwdriver Slot Type" Bialaddin bowl fire/Vapalux lamp pump Non Return Valve.
My Bialaddin bowl fire has a non return valve (NRV) seated in the base of the pump tube, it has a screwdriver type slot and I used a large screwdriver to remove the NRV. The old washer was very dry and fell to pieces very easily, I am very pleased I checked this.
I then unscrewed the bottom part of the NRV from the slotted end to reveal the spring loaded cup in which the NRV pip sits The NRV pip and spring can now be revealed Use a pin to remove the old pip and replace with new one, reassemble the NRV and refit with a new gasket, test pump when reassembled
Equally, do you know of a source for the pips and washers on their own? Base Camp don't have any new NRV assemblies, only salvaged ones...
You can get the entire V5 washer set (or NRV washer sets) for the Bowl Fire here in the Trading Post. I recently ordered the V5 kit and replaced all the washers and pump leather in my Bowl Fire and they all fit great. Excellent washers and great service from Ross. Dan