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Hammer Couplings and Shim Stock

Posted: Mon Jul 07, 2008 3:38 pm
by biggsauce
Well I caught the hybrid itch and I'm in the process of determining exactly which parts I need.

I'm looking at using either flanges or ahammer coupling instead of a union. I realize the flange route willresult in a slow reload time, but I'm not worried about that. Anyone had any experience with either of these options in respect to proper sealing with a burst disk?

Another idea i'm pursuing is stainless .001" shim stock. I have no idea of its burst pressure over a 1.5" diameter hole, but i'm shooting for 700psi burst. (i'll be hydrotesting the chamber to a minimum of 1500 psi and I'll also hydro the shims to see what I can get)


Anyone have any experience or thoughts on either of these options?

Posted: Mon Jul 07, 2008 3:43 pm
by potatoflinger
Those hammer couplings look pretty expensive, I don't know what flanges would cost you but they probably aren't more than hammer couplings.

Also, in your post did you mean 7000 PSI instead of 700?

Posted: Mon Jul 07, 2008 3:44 pm
by SpudFarm
i have thought as hel* on the flange for UPGBH10x
but it would be so poor reloading times that i went with a union.

a flange WILL seal, you got my word on it

Posted: Mon Jul 07, 2008 3:50 pm
by biggsauce
potatoflinger wrote:Those hammer couplings look pretty expensive, I don't know what flanges would cost you but they probably aren't more than hammer couplings.

Also, in your post did you mean 7000 PSI instead of 700?
Hooo no, this will be a 10x air/propane hybrid. I dont think the peak combustion pressure would exceed 1200psi, I just want the disk to burst at 700psi

Also I may have acces to some hammer couplings for next to free, so it's still an option. Same with the flanges, chamber, valves, hoses etc... :D

Posted: Mon Jul 07, 2008 3:51 pm
by rednecktatertosser
Those Hammer couplings dont seem to sell in sizes less than 6". The shim stock sounds like a good idea though, and I dont see why flanges wouldnt seal...

Posted: Mon Jul 07, 2008 3:52 pm
by potatoflinger
biggsauce wrote:
potatoflinger wrote:Those hammer couplings look pretty expensive, I don't know what flanges would cost you but they probably aren't more than hammer couplings.

Also, in your post did you mean 7000 PSI instead of 700?
Hooo no, this will be a 10x air/propane hybrid. I dont think the peak combustion pressure would exceed 1200psi, I just want the disk to burst at 700psi

Also I may have acces to some hammer couplings for next to free, so it's still an option. Same with the flanges, chamber, valves, hoses etc... :D
Oh, I thought you were talking about the chamber not the burst disk, never mind :oops:

Posted: Mon Jul 07, 2008 4:08 pm
by SpudFarm
heck you are so interesting biggsauce :D

Posted: Mon Jul 07, 2008 10:16 pm
by biggsauce
SpudFarm wrote:heck you are so interesting biggsauce :D
:lol: :lol: I seem to get that a lot

I have acces to smaller diameter hammer couplings, this was just the easiest link with a picture I could find. I'll probably end up with the flanges though the more I think about it.

It'll be interesting testing the shim stock though. Its available in many different thicknesses so I'm hoping to possibly need just one or two layers of stock to make my disks. Should be easier to handle than dozens of layers of aluminum foil...

Posted: Mon Jul 07, 2008 10:53 pm
by starman
Whoa baby those things are pricey! 6" is a lot large for burst disk usage. A 6" disk, burst pressure of 700 psi, those suckers would have to be mondo strong...that means a LOT!

I would keep your burst disk down to 2" or smaller...much more managable at that size.
biggsauce wrote:I have acces to smaller diameter hammer couplings, this was just the easiest link with a picture I could find. I'll probably end up with the flanges though the more I think about it.

It'll be interesting testing the shim stock though. Its available in many different thicknesses so I'm hoping to possibly need just one or two layers of stock to make my disks. Should be easier to handle than dozens of layers of aluminum foil...
Testing the material for burst strength will be a real challenge at those high pressures.

Posted: Mon Jul 07, 2008 10:59 pm
by biggsauce
starman wrote:Whoa baby those things are pricey! 6" is a lot large for burst disk usage. A 6" disk, burst pressure of 700 psi, those suckers would have to be mondo strong...that means a LOT!

I would keep your burst disk down to 2" or smaller...much more managable at that size.

Testing the material for burst strength will be a real challenge at those high pressures.


Ah the link I've provided has caused some confusion. My apologies. That link was the first link I found on google that showed what a hammer coupling was. 2" will be optimal for my application, and although I do have access to small diameter couplings, I am most likely follwing the flange route.