Completed Oxidizer Feed System and Test Stand

On Friday, I completed construction of the oxidizer feed system per the specs in my previous post. I removed the fittings and pressure regulator from the top of an old 72 cubic inch tank rated for 3000 psi used for paintball. I put the fitting designed to thread into the tank on the lathe and opened up the orifice to accept 1/4" NPT pipe. After tapping the threads, I installed a 1/4" NPT "T" fitting to accept the fill and arming valves. Before threading this assembly into the tank, a hole was drilled and tapped in the top of the tank to accommodate a 1/8" NPT venting valve and orifice designed for flow control.

72 Cubic Inch Nitrous Bottle

 The layout of the feed system is as follows:

Oxidizer Feed System Layout

Motor Feed and Pressure Tap

The pressure transducers were fitted with 12" standoffs filled with grease in order to prevent damage caused by the shock of high pressure combustion.

Pressure Transducers Fitted with Standoffs

Yesterday, a trip to the Home Depot inspired the test stand design "on the fly." I bought the parts and after returning home made this sketch:

Test Stand Drawing w/ Dimensions

 Here it is:

Test Stand

Test Stand

 The motor is fired vertically. This image shows the orientation of the feed lines, pressure tap, and later the forward closure.

Feed Line and Pressure Tap

The pressure transducers and standoffs are mounted as follows:

Pressure Transducers and Standoffs