Air Questions

[jlday1256]

Some questions about "blow" air. I have been through two cans of air analyzing a leak and learning the concept/construction. So....

1) I know that some of the airbrush companies have fittings for various sources of air (to include, at one time, Badger provided an attachment that allowed you to use a spare tire as an air source). Why not use a bicycle foot pump (with a regulator attached) to fill the gas bottle in the WTC? Yea, I know, Kazzer's kids need orthodontics and he needs to sell Paasche Propellant, but wouldn't a bicycle pump work as well?

2) And as an alternative, what about something like: http://www.amazon.com/Genuine-Innova...8PVBFCWZERWJTJ using CO2 in a cartridge holder/trigger that has a screw on Schrader Valve?

3) Would a PVC cylinder hold the necessary pressure to work as an alternative for the gas bottle in the WTC?

From a manufacturer (listing qualities):

Strength

PVC Schedule 40 and Schedule 80 pipe and fittings are highly resilient, tough and durable products that have high-tensile and high-impact strength. They withstand high pressure for long periods.

and finally:

2) What the heck is the purpose of the second valve stem attachment on the end of the motor bulkhead? Are we pressurizing the engine compartment?

[robert lipsett]

first all the pressure vessel of the wtc does not contain gas per say. it contains a fluid that expands into a gas to blow the tank. the amount of airpressure to egual the phase change from a liguid to a gas that blows the tank using propel would be too high to blow the tank as many times as the liquid will do it. the pressure fitting on the wtc is for letting out the air pressure built up by putting the cap in the wtc. If you do not have a bit of pressure to release by the valve then you have an airleak somewhere in the wtc. also this stem is very nice for removing the valve and attaching a hose to to blow air in the wtc to find airleaks. the propel is fairly easy to control but you can use propane from walmart too, it is a liquid in the little green bottles

[Kazzer]

2) And as an alternative, what about something like: http://www.amazon.com/Genuine-Innova...8PVBFCWZERWJTJ using CO2 in a cartridge holder/trigger that has a screw on Schrader Valve?

3) Would a PVC cylinder hold the necessary pressure to work as an alternative for the gas bottle in the WTC?

2. I see the idea, but this looks like an expensive solution to a simple problem. One shot of Propel or Propane is enough to keep a boat at sea for several patrols in one day, especially if you are using Snort.

3. I was told by His Worshipful Nastiness, in no uncertain terms only yesterday, that using a plastic or PVC container for holding ANY gas under pressure, was a quick way to commit suicide. These items shatter, sending sharp shards through the air.

[He Who Shall Not Be Named]

2. I see the idea, but this looks like an expensive solution to a simple problem. One shot of Propel or Propane is enough to keep a boat at sea for several patrols in one day, especially if you are using Snort.

3. I was told by His Worshipful Nastiness, in no uncertain terms only yesterday, that using a plastic or PVC container for holding ANY gas under pressure, was a quick way to commit suicide. These items shatter, sending sharp shards through the air.

Can't use CO2 in our gas ballast sub-system -- CO2 is liquid at room temperature at a pressure a bit greater than 800 PSI. The flexible tubes in the sub-system burst (a safety feature) at a bit over 400 PSI. Propellant is typically in the liquid state at room temperature at 70 or so PSI. That's the nominal pressure the gas ballast sub-system is designed to work at.

[robert lipsett]

pv=nrt Pressure =p Volume =v for the subdriver nrt should be a constant. 1 atmosphere of pressure is equal to 15 lbs. I do not know what the ratio of the volume of the copper pressure reservoir is as compared to the ballast tank is but what ever that ratio is has to be multiplied by 15 lbs in order to have enough pressure to blow the ballast tank. Air pressure gets way to high too fast. the expansion of the state change from liquid to gas is a much better alternative and the pressures are reasonable to deal with. Dave is understating the danger of high pressure air, its a bomb and microfractures or weaking due to ultraviolet exposure is dangerous. hard to believe sucide is an understatement but it is.

[jlday1256]

Thanks. A lot of great answers and instruction on pressured systems. That's what I get for thinking. I will stick with the canned propellant and the current "metal cylinder".

[He Who Shall Not Be Named]

Thanks. A lot of great answers and instruction on pressured systems. That's what I get for thinking. I will stick with the canned propellant and the current "metal cylinder".

Very good. Your question presented the opportunity to clarify how the system works as well as its needs limitations, and utility.

David