Paul,

 

I will take pix next time I am out at the hangar.  I have a small nitrogen tank (about 2' tall) that I bought (full of N) from a welding supply house (like BOC gases).  It has a pressure sensor before the adjustable regulator and another sensor after to note the fill pressure (I have two for an accurate hi and lo pressure range).  There are at least two ways to connect to the high pressure Schrader valve on the strut:

 

1. A screw on device that does not depress the valve but uses superior incoming pressure to overcome the spring in the valve. 

2. A device at the end of the fill hose that, after being screwed on allows the turning in of a pusher that depresses the valve.

 

#2 is preferable because the fill pressure can be made exact whilst #1 shuts off incoming gas when the spring closes the valve giving an inaccurate pressure reading.

 

With the strut empty and compressed, my procedure is to open the tank valve, open the regulator slightly to fill the hose with N, close it and immediately connect the hose end to the Schrader valve, screw in the valve stem depressor, open the regulator very slowly until the desired pressure is reached, un screw the depressor until the valve is closed, close the regulator, slowly unscrew the hose connector relieving its pressure and then shut off the tank.

 

If the strut is overfilled, I use an appropriately sized pin punch and a light hammer to tap the punch on the valve stem to release bits of gas.  It is not humanly possible to manually depress the stem and only let out a little bit of gas. (This is especially true on TK-5 Debongers since such little gas is used.)

 

Scott Krueger

 

PS I bought the full tank in 1997 and it is only half used (or half full, depending on your world view).

 

 

I have nitrogen and gauges. I would like to get a setup for filling the struts and looking for recommendations.

Paul
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