Hydraulic press hoses -- rigid metal?

L

lytefoot45

Joined
May 25, 2007
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Every thread I have ever read about building a hydraulic press stresses the need for hoses that are specially constructed for the application -- 3000 psi, metal sheathing, special fittings, etc. -- and extra
protection in case a line fails or a hot billet is dropped. I have never seen any mention of using rigid metal lines instead of flexible rubber hoses.

Is there a reason that rigid lines are not commonly used? Price? Difficulty of construction? Other?

Thanks in advance!
Wayne
 
I've been using regular rubber flexible hoses on my hydro press for about 15 years. Never a problem at all. But mine are routed out of the way of the hot work.

I don't think ridged metal hoses would hold up long with the vibrations from the motor/pump?
 
i make hoses

construction can be half way difficult on short bends and on short tubing. being 1/4" off can make the flare not seat properly on smaller/shorter stuff

hard tubing is generally cheaper in materials. if you bring your equip to a hose shop they should be able to make you some hard lines for a reasonable price(thats if you can move the equip.). depending on hoses and angle of fittings, flexible is generally more expensive but takes less time to make. if you dont have anything. it might cost the same price. 1 is more time and labor, the other is more costly parts

my 2 wire hoses, which i consider standard
1/4 or #4 is rated 6000psi
3/8 or #6 is rated 5000psi
1/2 or #8 is rated 4000psi

the larger the hose the lower pressure rating it can hold. also most hoses have a burst pressure of 4 to 1.


there is nothing wrong either with way you go

need any more help give a shout
 
Don Hanson III said:
I've been using regular rubber flexible hoses on my hydro press for about 15 years. Never a problem at all. But mine are routed out of the way of the hot work.

I don't think ridged metal hoses would hold up long with the vibrations from the motor/pump?
Click to expand...

steel hard lines will last as long if not longer. steel will hold up to vibration. aluminum wont.

most all manufactures of hose say 8 yrs is average life expectancy of their rubber, but ive also seen stuff last 15+ yrs, and also only last 3-4 yrs.

generally if it doesnt move and is out of environmental stresses(out of sun, extreme changes of temp, ect) it should last closer to a maximum life.
 
You can buy the hose ends you put on yourself and buy hose by the foot. The ends you install without a press hold just as much pressure and if you damage them you can reuse with a new piece of hose.
 
lots of local part stores will also make more standard hoses, but might not have the best adapter assortment.

if they are a gates distrbutor, weatherhead or parker.

from my areas of texas thats whats seen most from smaller part stores or larger ones like orielys
 
Some hydraulic fittings use NPT threads.
It makes you think you can use "normal pipe"

Seamed pipes are made for water.

They max out at a fraction of hydraulic pressure.

There are proper seamless hard lines you can use, but by the time you go to proper hard lines
I don't think it's simpler or cheaper.
& you probably need some flex lines in it to reduce hammering.


I think that cylinder on top presses are much smarter than cylinder on bottom, just for that to keep slag from hitting hoses.


http://www.anvilfire.com/FAQs/hydraulic_piping.htm
 
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nowadays npt(pipe) fittings will hold the pressure you want.

most likely, the fittings on your pumps and control valves will go back to pipe or boss oring fittings, unless its from europe.


what ever type of fittings it comes with will be fine.

to make cheaper. try to get adapters back to jic/an/37degree(all the same just different name) fittings. angled adapters are cheaper than angled hose fittings. straight hose fittings are cheapest, as are straight sizes of hose to fitting(#6 hose to #6 fitting) jumping those sizes 6 to 8 will make them more expensive and sometimes harder to get.
 
bladeright said:
nowadays npt(pipe) fittings will hold the pressure you want.
Click to expand...

Yes, but there is a difference between NPT hydraulic fittings and NPT pipe fitting on the shelf of the local Home Depot.
Wall thickness is far different & so are the pressure ratings.
 
12345678910 said:
Yes, but there is a difference between NPT hydraulic fittings and NPT pipe fitting on the shelf of the local Home Depot.
Wall thickness is far different & so are the pressure ratings.
Click to expand...

ive never seen a home depot or another big box store like that sell hydraulic stuff. the only stuff they sell to my knowledge is black cast iron pipe, which is not the same stuff, or even considered hydraulic
 
Many thanks to all of you for your responses! I love this place because I can learn so much so quickly!
To summarize what I've learned from this question:
Obviously, a hydraulic press creates more vibration than I realized (I don't have one yet.)
Metal lines might be more prone to failure than flexible given a similar amount of vibration.
Fitment for hard lines would require more precision than flexible to ensure proper flare alignment.
With hard lines, you would still want to include some amount of flex in the system.
Cost is not substantially different once all factors are included but flexible is easier to have constructed.
Proper routing and protective shields where needed provide sufficient safety.
Given the safety concerns with hot hydraulic fluid, the best route for me is to have hoses professionally made.

THANKS!
Wayne
 
Seamed steel pipe in small diameters is almost unheard of now. The schedule of the pipe and fittings is important. Schedule 80 3/4 seamless has a max working pressure of 3800 psi with a 25% reduction for threaded fittings of the same weight class. (2700psi) 1' is the same. Bursting strength is 17,600psi. Schedule 160 3/4" goes up to a WP of 8,500 and bursting of 25000. 1/2" to 3/4" steel tubing requires max wall thicknesses to work above 2000psi. Remember that as diameter increases max pressures drop.

I plan to use 1" pipe for the longer runs and short hoses for connecting to my pump (vibration point) and to my ram (flex point). But, then I make piping systems for a living and can gather what I need in the way of pipe for little to nothing.
 
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