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 62 users online :: 5 registered, 0 hidden and 57 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

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

The Team
Administrators
Global Moderators
global_moderators.png CS

400psi piston vavle

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

Unread postAuthor: POLAND_SPUD » Fri Jan 11, 2008 6:41 pm

I am just wondering... what type of fittings do you use most of the time ? steel, brass or iron ? iron is likely to have the lowest burst pressure of all three right ? anyidea what is the operating pressure of 1/2" iron fittings becasue I have LOTS of them

ALI i've already taken my QEV to 250 psi... but I am still waiting for your results before I go above 300 or near 400 psi... :D sorry I am too afraid of dammaging my precioussssss QEV
:wink:
  • 0

User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: ALIHISGREAT » Sat Jan 12, 2008 2:30 am

POLAND_SPUD wrote:I am just wondering... what type of fittings do you use most of the time ? steel, brass or iron ? iron is likely to have the lowest burst pressure of all three right ? anyidea what is the operating pressure of 1/2" iron fittings becasue I have LOTS of them

ALI i've already taken my QEV to 250 psi... but I am still waiting for your results before I go above 300 or near 400 psi... :D sorry I am too afraid of dammaging my precioussssss QEV
:wink:


ermm well iron is the cheapest and brass is used more for smaller sizes and i haven't used steel yet.

and its alright for me to damage mine but not for you to damage yours :wink: and if your polish QEVS are soo cheap maybe you should try with yours first...
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: POLAND_SPUD » Sat Jan 12, 2008 10:08 am

OK I've tried first..... :) today I finally had some time for spudding.... I've fired atleast 15 shoots at 300psi.... and one at ~ 340 psi
I openned the QEV and piston still looks perfectly ok... so i assume that there wouldn't be any problems with using QEVs at 400 psi
  • 0

User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: ALIHISGREAT » Sat Jan 12, 2008 12:41 pm

POLAND_SPUD wrote:OK I've tried first..... :) today I finally had some time for spudding.... I've fired atleast 15 shoots at 300psi.... and one at ~ 340 psi
I openned the QEV and piston still looks perfectly ok... so i assume that there wouldn't be any problems with using QEVs at 400 psi


hmm i didn't foresee any problems but i think the problems (if any will come after lots of use at 400psi but that shouldn't be a problem as i won't be using 400psi all the time.
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: POLAND_SPUD » Sat Jan 12, 2008 2:41 pm

BTW I found this http://aukcja.onet.pl/show_item.php?item=294026716
16X1 mm brass pipes.... for about 4.5 pounds for 1kg :-D
any idea what is the operating pressure of brass pipes ? higher than copper or lower ?
  • 0

User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: DYI » Sat Jan 12, 2008 2:48 pm

Depends what kind of brass pipe. All copper tube 1" and under has a burst pressure of over 3kpsi. SCH 80 brass pipe would be incredibly strong, but horribly expensive. Copper tube is more economical than brass pipe in all sizes. Brass just isn't worth it. Steel is better than brass for non-corrosive applications, and far, far cheaper.

Normal 1/2" SCH 40 malleable iron fittings are rated for 150 psi, and have a burst pressure of well over 2kpsi. I've personally used malleable iron fittings in 2" size up to 470 psi, repeatedly, with no ill effects, even in extreme cold.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: POLAND_SPUD » Sat Jan 12, 2008 2:52 pm

DYI thx....
but i don't get it brass is not practical ? It would be great for barrels becasue there are lots of sizes available..... and for chambers too - 24X4 mm pipe for 4 pounds per 1 kg... it's even cheaper than the 16 mm one... and cheaper than steel...
  • 0

Last edited by POLAND_SPUD on Sat Jan 12, 2008 3:20 pm, edited 1 time in total.
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Sponsored

Sponsor
 


Unread postAuthor: DYI » Sat Jan 12, 2008 2:56 pm

Well, there is no such thing as copper pipe for one thing. If you tell me the schedule of the pipe, or dimensions, as well as the fatigue strength of the brass that the pipes are made of, I can give you a rough idea of their burst pressure.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: POLAND_SPUD » Sat Jan 12, 2008 3:41 pm

soo copper pipes are acctually brass pipes ? sorry I've been using steel only so I don't know much about copper pipes/fittings......

what about this size, 24 mm either ID or OD, it's not stated anywhere; 4 mm thick wall...
it is M63z4 (it's a name of alloy I found that it is more often described as CuZn37 Rm370; when I googled CuZn37 it turned out that the number 37 tells how much Zn there is in this alloy.... )
http://www.imnr.ro/aliaj13eng.htm - and this suggest that it is possibly the 'standard' brass used in pipes
  • 0

User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: ALIHISGREAT » Sat Jan 12, 2008 3:56 pm

could someone please GGDT this gun for me because i can't get it for various reasons.

28mm x 50cm chamber
25mm piston with a 20mm porting piloted by a 1/2" qev
20mm x 1.5m barrel (17.5mm id)
operating pressure 400psi :twisted:
ammo 0.68 paintball (17.27mm i think)
anything i have missed?

thanks Alasdair
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: DYI » Sat Jan 12, 2008 4:10 pm

There is copper tubing, but no copper pipes.

@Ali: I can't do the GGDT because I don't know the QEV specs. I'm sure someone around here does though.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: al-xg » Sat Jan 12, 2008 4:21 pm

7.8CV flow ; 2ms open time something like that
  • 0

User avatar
al-xg
Colonel
Colonel
 
Posts: 643
Joined: Fri Jan 19, 2007 12:29 pm
Reputation: 0

Unread postAuthor: ALIHISGREAT » Sat Jan 12, 2008 5:35 pm

DYI wrote:There is copper tubing, but no copper pipes.

@Ali: I can't do the GGDT because I don't know the QEV specs. I'm sure someone around here does though.


well Al-XG gave some specs and it doesn't have to be spot on.
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: POLAND_SPUD » Sat Jan 12, 2008 6:19 pm

I have no idea how much does 0.68 paintbal weights so I put 15g projectile instead.
with 2 grams projectile instead - GGDT shows 384 m/s
  • 0

Attachments
ggdt.jpg
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: ALIHISGREAT » Sat Jan 12, 2008 7:28 pm

thanks, they were the kind of performance figures i was hoping to see :twisted: i think paintballs are 3-4g :) and i might just have to make myself some 15g ammo because 330j is one hell of alot of power :twisted:

edit: could you also model it with a lighter piston because i'm using hdpe which is ~0.94/cm3 so i would need a 50cm3 piston to do that which would be more than 10cm long :shock: so a 5cm piston would be 23g :) and the valve is a barrel not chamber sealer thanks Alasdair
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

PreviousNext

Return to General Spud Cannon Related

Who is online

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

Reputation System ©'