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 44 users online :: 4 registered, 0 hidden and 40 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

Expanding Air Line

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

Expanding Air Line

Unread postAuthor: DYI » Sun Dec 26, 2010 11:09 am

A recent project of mine includes a 3/8" ID, 300psi rated air hose from Lowes, which I believe is the "Task Force" brand PVC hose (although I've been unable to find a specsheet for it). After being pressurised to 110psig for 12 hours, I noticed that the hose had expanded uniformly to 20mm outer diameter, from the initial 16mm. I suspect that this is a result of air seeping between the two PVC layers, as the fiber weave in between layers shouldn't be able to expand to this extent. This is brand new hose, with no sign of degradation other than the expansion.

I suspect that it's caused by a leak in the inner PVC layer pressurising the outer layer and expanding it away from the fiber reinforcement, which seems to be supported by a cursory inspection. Has anyone here experienced similar behaviour from air hoses under pressure for an extended period of time?
  • 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: jimmy101 » Sun Dec 26, 2010 11:55 am

You might measure the length of the hose when it is expanded. The fiber weave can expand if the length of the hose decreases. Is the hose still expanded if you remove pressure from it for a couple hours?
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3129
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: DYI » Sun Dec 26, 2010 12:41 pm

That's a good idea jimmy. I measured the hose, and its length had decreased by ~1". After taking the measurement, I dropped the hose's internal pressure down to atmospheric, after which it contracted to its initial diameter. However, the hose feels very soft now compared to the undamaged spare chunk I have, and I certainly wouldn't pressurise it again.

Looks like this one's a write off. I guess I'll replace it with hydraulic hose tomorrow...
  • 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: metalmeltr » Mon Dec 27, 2010 8:28 am

I have a grease gun hose on my fridge compresser-4500psi rating-first time I pressurize it an air bubble got under the outer casing and the casing blew up. The casing now has a sizable hole in it, it is still in service because it apperars to still hold pressure.
Task force really isnt a good brand. I dont trust their tools.
  • 0


metalmeltr
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 426
Joined: Thu Dec 18, 2008 3:42 pm
Location: united states
Reputation: 0

Unread postAuthor: Gippeto » Mon Dec 27, 2010 12:58 pm

[quote="metalmeltr"]Task force really isnt a good brand. quote]

Really? :)

You get what you pay for...especially when it comes to tools....more often than not IMNSHO.
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: Fnord » Tue Dec 28, 2010 6:00 pm

Depending on how obtrusive the regular hose is vs. hydraulic line(or if that even matters) it may be better to just wrap it in wire thoroughly. A couple layers of electrical tape should keep the wire in place.
  • 0

Image
User avatar
Fnord
Major General
Major General
 
Posts: 2244
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Reputation: 7

Unread postAuthor: psycix » Thu Dec 30, 2010 9:23 am

@metalmeltr

I also use grease gun hose for my fridgy. It can leak air into a bubble under the surrounding skin.

BTB did that with the same hose, and bursted the bubble with a knife. He said it made an insane bang, indicating a lot of pressure in it.
So beware, it may release air violently when such a hose-skin bursts.
  • 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
 


Return to Construction Materials/Ammo Discussion

Who is online

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

Reputation System ©'