Why not use rubber joints with hose clamps?
Why not use rubber joints with hose clamps?
(OP)
I am looking for rubber expansion joints with straight sleeves to use with hose clamps at 6-10 BAR working pressure. The first reactions are not to do this, but why? Can anyone explain me why I should not do this? When they are tested on burst (3-4 x working pressure) it should be Ok, or not?





RE: Why not use rubber joints with hose clamps?
Good luck,
Latexman
RE: Why not use rubber joints with hose clamps?
RE: Why not use rubber joints with hose clamps?
Do you have any imposed displacments to absorb or maybe you just want a cheap joint ?
Passing a burst test reflects just one facet of operation. The joint may be subjected to torsion, pressure extension, vibration, misalignment, shock, none of which are covered by a test. A flanged joint has far more inherent safety.
RE: Why not use rubber joints with hose clamps?
All of the uncertainties of mixing, molding, curing affect each parts' mechanical properties (tensile strength, fatigue life), thus rubber parts typically have much greater statistical variation in these properties.
Finally, most rubbers degrade by a variety of mechanisms over time. Rubbers are quite visco-elastic, and can creep under load, or relax. Chemical, oxidation, UV, and thermal degradation mechanisms can also come into play.
All that said, I've used similar parts, and seen them used, and they do work when the above variables are accounted for. One thing your coupler installation in your photo does not seem to account for is the tendency of a bellows-type joint to expand under pressure, unless there are pipe restraints elsewhere (out of frame) to react that load.
RE: Why not use rubber joints with hose clamps?
http://www.metraflex.com/flex_rubber.php#flex
RE: Why not use rubber joints with hose clamps?
RE: Why not use rubber joints with hose clamps?
RE: Why not use rubber joints with hose clamps?
Good luck,
Latexman
RE: Why not use rubber joints with hose clamps?
@btrueblood
Thanks for additional info. Regarding the tendency of a bellows-type joint to expand under pressure; we are now testing a newly developed sleeve joint with bellow that does not want to expand/contract under pressure. First results look promising, even at high pressures.
@DLiteE30
I checked the Metraflex joints but they are only 75psi...
@Pennpiper and Artisi
The rods are there for security as this is a test set-up to test this joint before actually using it.
RE: Why not use rubber joints with hose clamps?
The only other application has been on 150 psig plant air.
Look at the top three brochures on the site posted below.
http:/
RE: Why not use rubber joints with hose clamps?
As mentioned above, we are now testing a sleeve type that does not expand/contract under pressure and therefore can handle high pressures (600 psig tested without pull-off or burst at this moment). Are there other things we should consider?
RE: Why not use rubber joints with hose clamps?
So how does this sleeve joint work ?
Are you saying it has no end thrust ? Is it somehow pressure compensating or is there some restraint axially ?