The air line broke off the bottom of the "burst chamber" the 1st time
we used it. I picked up parts from Home Depot and modified the
burst chamber to include the brass featured here. The pressure gauge
was soon replaced with an Omega Engineering DPG5500B-500G digital
min/max/zero pressure gauge. We needed to measure "burst pressure"
reliably. The gauge on the FP 200 bike pump got us to within +/- 20%.

The white vinyl "burst membrane" in the foreground burst around 60psi
and sent the rocket up about 70'. You can use multiple membranes for
varying maximum heights, but 230psi from a bike pump isn't a sure thing...