Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 42 users online :: 4 registered, 0 hidden and 38 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Shrader regulators

A place to ask general spud cannon related questions.
Sponsored 
  • Author
    Message

Shrader regulators

Unread postAuthor: Sticky_Tape » Fri Jul 25, 2008 9:48 am

Has anybody thought of linking shraders for a non ajustably regulator?
I am aware that Gippeto did tests on a shrader and the crack pressure is about 70psi. Now if the tank pressure was 300 psi and you had 3 shraders linked fill side towards tank than the output pressure would be 90psi right? Lets go through this 300psi cracks open the first shrader the space between the first shrader and second shrader would be 230psi the second shrader get's cracked by the 230psi the pressure would then be 160psi between the second and third shrader third gets cracked and the output is 90psi.
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: psycix » Fri Jul 25, 2008 10:12 am

An -70psi "regulator"? Maybe.
Though on what pressure does it close again?
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: Sticky_Tape » Fri Jul 25, 2008 11:32 am

probably just under 70 maybe?
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: Antonio » Fri Jul 25, 2008 3:20 pm

why would it subtract 70psi everytime? I dont really get it, I think all valves would open as the pressure is always above 70psi.
  • 0

User avatar
Antonio
Colonel
Colonel
 
Posts: 508
Joined: Sun Aug 13, 2006 2:38 pm
Reputation: 0

Unread postAuthor: Sticky_Tape » Fri Jul 25, 2008 3:57 pm

Never mind someone lock the thread I wasn't thinking right.
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: Lentamentalisk » Fri Jul 25, 2008 8:55 pm

It should keep the down stream air line at exactly 70psi less than the inlet pressure, assuming that the down stream side doesn't have a larger surface area to work on. The spring on each one provides "70psi" of force on the little nib.
  • 0

Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Lentamentalisk
Brigadier General
Brigadier General
 
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.
Reputation: 0

Unread postAuthor: psycix » Tue Jul 29, 2008 7:40 am

Possibility is, that once it has opened, surface area changes (more area comes into play, like the frontal area on a piston valve) And thus, it closes on a different pressure then opening.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: jimmy101 » Tue Jul 29, 2008 12:08 pm

Similar ideas have been floated before. Instead of using a schrader plumbed "backwards" you can use a pressure relief valve, which is basically identical to a schrader. For example, the pressure relief valve from a hot water heater. The heater valves have much larger throats then a schrader and would have much better flow, if flow is important. But, this is basically a pressure regulator and the valve will close again once the rpessure has dropped enough. How far the pressure has to drop (the valve's hysteresis) will depend on the design of the valve. (Interestingly, hot water heaters aren't rated in flow, for example gallons per minute, they are rated in BTUs.)

This type of valve has also been suggested as a safety pressure relief. Accidently built a combustion gun out of cell core PVC? Put a 50 PSI pressure relief valve on it to insure the pressure never rises above 50 PSI.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3130
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: psycix » Wed Jul 30, 2008 12:27 pm

jimmy101 wrote:This type of valve has also been suggested as a safety pressure relief. Accidently built a combustion gun out of cell core PVC? Put a 50 PSI pressure relief valve on it to insure the pressure never rises above 50 PSI.

I wouldnt trust on that unless the relief valve was very large in diameter and very fast acting.
The pressure rises up in a few milliseconds, and in that time, a small relief valve will not have the time to let enough air out. A big burst disk would be an better idea.
Against accidental pneumatic overfillings, a pop-off is always a good idea, since the pressure builds up slowly enough.

Also, it may not be the pressure that breaks it, but the shockwave.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: jimmy101 » Wed Jul 30, 2008 2:08 pm

psycix wrote:
jimmy101 wrote:This type of valve has also been suggested as a safety pressure relief. Accidently built a combustion gun out of cell core PVC? Put a 50 PSI pressure relief valve on it to insure the pressure never rises above 50 PSI.

I wouldnt trust on that unless the relief valve was very large in diameter and very fast acting.

Good point. Any mechanical device is going to be fairly slow compared to the rate of combustion, by the time it reacts it may be too late.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3130
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Return to General Spud Cannon Related

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'