Ken:
Ben Brocket has tested more liquid rockets than god. He is not the person
here who does not know what he is talking about; nor is Ben the person here
being confrontational.
Jim French, who was chief engineer at Amroc told me the issue was an
underpowered actuator. He allowed that the existing actuator might have
worked if the valve had been wrapped in heat tape and warmed before launch;
that, however, would have effected the initial Lox quality. He did not
mention a gas trickle as an option.
I use titanium in my solid rockets: nose tip, fin leading edges, nozzle
exhaust extension.
The Antares launch vehicle uses dozens of Titanium high pressure He tanks
*inside* the Lox tank. Neither that vehicle nor the hundreds of Russian
and Soviet heritage designs have ever had a failure caused by the presence
of Ti in a Lox bath.
Bill
On Mon, Mar 15, 2021 at 11:35 AM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
Titanium, scandium,rhenium and other exotic NON ferrous metals are not
found in amatuer rocket systems so please be real. And when SpaceX used Ti
they blew up their Dragon test capsule.
Mine as well as many other LOx systems I've worked with almost never used
insulation in my 50 years of experience both amatuer and professionally.
The only exception was run tanks at the facility at EMRTC in Socorro NM
which we often had countdown holds so insulation was beneficial to lower
boil off. Insulation is a waste of time and it's ugly.
Lines should be kept short for a number of practical reasons including
delta-P losses, resonance potential, hydraulic hammer,etc.
This site is supposed to be educational not adversarial and
confrontational, you should not inter comments that you have no hands on
experience with yourself
or are an experienced educator in the particular field under discussion.
Ken
On Mon, Mar 15, 2021 at 3:50 AM Ben Brockert <wikkit@xxxxxxxxx> wrote:
On Sun, Mar 14, 2021 at 11:05 PM roxanna Mason
<rocketmaster.ken@xxxxxxxxx> wrote:
Some seals/o-rings need changing and all non ferrous metals arecom[patabler with LOx. Insulation is usually non necessary with test stand
components only extended storage is insulation necessary nother like LH2
which requires insulation under all circumstances.
Titanium is not particularly compatible with LOX.
Insulation on cryo test stands is almost always worth the effort.
Stands rarely have as short of propellant paths as rockets so
insulating the lines helps to get the same quality of LOX to the
engine. It's also a quality of life thing, a stand that isn't
insulated will end up being perpetually wet from melted frost. If it's
a high throughput stand where you're testing every day for weeks, it's
very easy to build up a block of ice that can damage things like
instrumentation when the stand is emptied and starts to melt.
A good middle ground for amateur and lower duty cycle stands is to
insulate lines away from fittings; you get most of the benefit but can
still see leaks.