Hi All,
Just looking at two options of cylinders;
Nominal Contents volume
Y- 4.76 m3
W- 11.03 m3
Nominal Pressure at 15°C (bar) 230 bar
Cylinder being filled -
48.2 cu Ft
Max 2216 psi
How many refills am I likely to get? Not sure where to start with the maths.
Aithre is spelt with an “i” not a “y”
Hello,
In the search of portable CO detector and/or easy pulse oxymeter, I’ve found Aythre products:
pulse oxymeter fixed on headset (need a USB power):
USB-key format CO detector:
The pulse oxymeter is also linked to CO detector and can provide haptic feedback on some threshold alert. Unfortunately, they are managed also through an Iphone app..
UdoR wrote:
My cylinder dates 1967.
My vintage 
I’m surprised you say 10yrs test interval.
I know some types are 10yr but didn’t think that was types usually used in aircraft. Thats great for you.
5yr is very common in the older airframes with steel cylinders.
Fortunately most Cessna Cylinders are Steel and ‘on condition’ forever.
The downside is that while I’ve a contact licensed to do the American test (DOT) it’s still a bit of hassle to get them out, every 5 years.
Emir wrote:
No. They are usually kevlar or carbon.
My cylinder dates 1967.
Peter wrote:
was steel (and heavy)
Yes that’s closer to mine. Good point about steel: 10 years time between checks. Bad thing is it IS heavy.
GA_Pete wrote:
messing around with portable equipment is not a fuss with only 2 onboard but may be a pain with more Pax. Thus the investment helps with your appreciation/enjoyment of the aircraft.I was specifically looking for built-in when I purchased our aircraft.
Well initially I wouldn’t have bothered to carry along some portable stuff. But I had my experience already with a blocked oxygen hose in FL190. Aditionally with 4+ POB it is just more stuff flying around the cabin.
Actually I’m using the oxysaver cannulas and they’re quite ok on gas usage, really. 2 POB 12 hours of flight, half of that FL140, other half FL190, still plenty of oxygen left, maybe half cylinder used. That’s ok for me. I refill in my hangar.
I’ll relax and wait for what happens.
Maybe on new models, but the TB21 was steel (and heavy) and AFAIK all the old turbo airframes were also steel – they long-pre-date composite-anything.
Peter wrote:
The fitted ones are normally steel.
No. They are usually kevlar or carbon.
Peter wrote:
2k sounds quite cheap actually
No. $2k is max price – the usual aviation price is $1.7k, normal price is $300-$500.
A cylinder is a cylinder. The fitted ones are normally steel. 2k sounds quite cheap actually; this stuff is normally a major part of the extra cost of a turbo aircraft (top overhauls being another).
A guy called Paul Turner – @paul – here spent a lot of time and £££ certifying a composite one for his TB21.
The other option is to plumb in a “portable” cylinder, like the MH “48 cu ft” one, 1st stage regulator, and feed the 20psi or so into your o2 plumbing, and then use an O2D1 for each seat, or O2D2 for 2 seats at a time. The fitted systems are constant flow and terrible on gas usage – see here – but way back there was a lot less knowledge within GA (pre-internet) and people just didn’t care. You are wasting at least 80% of the gas in your fitted system. The one thing you need to sort out is that the pressure gauge (which is on the cylinder) needs to be visible to the pilot, and the valve (likewise) needs to be accessible to the pilot also. The fitted systems feed the 2000psi gas to the front panel via a copper or steel pipe with a tiny internal diameter, like 0.5mm, and the 1st stage reg is pilot-accessible.
Enquire with some other shops if there is a chance of some remedial work?
The cost of replacement is high, but may have,
a, an impact of resale of the aircraft to the tune of that, or more without built-in
b, messing around with portable equipment is not a fuss with only 2 onboard but may be a pain with more Pax. Thus the investment helps with your appreciation/enjoyment of the aircraft.
I was specifically looking for built-in when I purchased our aircraft.
