Test of Pressure Relief Valve in a N2O hybrid rocket motor

The data below are the results from testing a pressure relief valve used to regulate tank pressure in a N2O hybrid. The tank was filled, allowed to stabilize, "topped-off," then purged. At a constant pressure, the N2O should be at a constant temperature and density. The pressure relief valve is configured to vent at 400 PSIG, and a redundant valve is configured to vent at 450 PSIG.

Full Trace

Zoom to active stabilization region

It appears the pressure relief valve "cracks" when the pressure exceeds 400 PSIG, then opens and closes quickly stabilizing around 375 PSIG. The stabilization is loud and easy to hear.


(boring) Video of the test