Attaching high pressure braided hose to metal pipe
Discussion
I've fitted an electro hydraulic power steering pump from a Citroen Saxo to my car and it's currently plumbed in using a compression fitting (on the high pressure side) between pump and the original pipe that goes under the engine to the rack. The problem is I'm not totally confident that the compression fitting on the flexi hose is the best way of plumbing it all together.
A screw in fitting is available to easily fit a braided hose directly to the pump but how could this be connected properly to the metal pipe under the sump? It's not obvious to me how this could be done and what sort of fittings are available to do this. Could the metal pipe be swaged somehow to allow the hose to be fitted?
Any ideas?
A screw in fitting is available to easily fit a braided hose directly to the pump but how could this be connected properly to the metal pipe under the sump? It's not obvious to me how this could be done and what sort of fittings are available to do this. Could the metal pipe be swaged somehow to allow the hose to be fitted?
Any ideas?
In the first instance compression fittings (assuming they are proper high pressure compression fittings) are MORE than capable of the pressures in a power steering systems.
In your other question, without seeing closer the other fittings, it is virtually impossible to come up with alternatives.
In answer to another suggestion above, one thing I would NOT be doing is welding a fitting onto a high pressure hydraulic system in an engine bay!
One more thing, if I am seeing your first pic correctly, you have fitted the union on the solid pipe FAR too close to the bend to give a 100% reliable connection.
In your other question, without seeing closer the other fittings, it is virtually impossible to come up with alternatives.
In answer to another suggestion above, one thing I would NOT be doing is welding a fitting onto a high pressure hydraulic system in an engine bay!
One more thing, if I am seeing your first pic correctly, you have fitted the union on the solid pipe FAR too close to the bend to give a 100% reliable connection.
Edited by andyiley on Tuesday 24th February 08:03
andyiley said:
In the first instance compression fittings are MORE than capable of the pressures in a power steering systems.
In your other question, without seeing closer the other fittings, it is virtually impossible to come up with alternatives.
In answer to another suggestion above, one thing I would NOT be doing is welding a fitting onto a high pressure hydraulic system in an engine bay!
One more thing, if I am seeing your first pic correctly, you have fitted the union on the solid pipe FAR too close to the bend to give a 100% reliable connection.
I agree with all of this, I'd want to know exactly what the pipe is made of before making any attempt to weld something onto it. There is no cause to suggest that compression fittings aren't up to it, OEMs use crimped fittings all the time. In your other question, without seeing closer the other fittings, it is virtually impossible to come up with alternatives.
In answer to another suggestion above, one thing I would NOT be doing is welding a fitting onto a high pressure hydraulic system in an engine bay!
One more thing, if I am seeing your first pic correctly, you have fitted the union on the solid pipe FAR too close to the bend to give a 100% reliable connection.
andyiley said:
In answer to another suggestion above, one thing I would NOT be doing is welding a fitting onto a high pressure hydraulic system in an engine bay!
Do you mean physically welding the pipe while it's still attached to the car (it would be removed to do any work on it) or do you mean I shouldn't even considering using such a fitting?Edited by andyiley on Tuesday 24th February 08:03
No, I mean welding anything into a system that will contain high pressure hydraulics.
To EVEN attempt it I would need to see the qualifications and training records of the "coded welder" who was going to attempt it, I would then insist on a 200% pressure test and an x-ray inspection of 100% of the weld, otherwise FORGET IT.
You are going to put high pressure hydraulic fluid (that is explosive when in a high pressure mist) through it in an engine bay remember!
To EVEN attempt it I would need to see the qualifications and training records of the "coded welder" who was going to attempt it, I would then insist on a 200% pressure test and an x-ray inspection of 100% of the weld, otherwise FORGET IT.
You are going to put high pressure hydraulic fluid (that is explosive when in a high pressure mist) through it in an engine bay remember!
I suspect a few people might be slightly over estimating the performance of that little Saxo PAS pump (actually a std HPIcanada "powerpack")!
If we assume that pipe is 10mm ID, with 100bar on it (saxo pump can only manage about 80bar steady state) that's just 785N trying to rip the fitting off, (~80Kg for normal people). And so whilst, Yes, it does need to be welded or brazed properly, it's certainly not beyond the remit of a decent "hobby" welder.
If we assume that pipe is 10mm ID, with 100bar on it (saxo pump can only manage about 80bar steady state) that's just 785N trying to rip the fitting off, (~80Kg for normal people). And so whilst, Yes, it does need to be welded or brazed properly, it's certainly not beyond the remit of a decent "hobby" welder.
BritishRacinGrin said:
I agree with all of this, I'd want to know exactly what the pipe is made of before making any attempt to weld something onto it. There is no cause to suggest that compression fittings aren't up to it, OEMs use crimped fittings all the time.
A proper crimped hydraulic hose is slightly different than a DIY compression fitting.andyiley said:
No, I mean welding anything into a system that will contain high pressure hydraulics.
To EVEN attempt it I would need to see the qualifications and training records of the "coded welder" who was going to attempt it, I would then insist on a 200% pressure test and an x-ray inspection of 100% of the weld, otherwise FORGET IT.
You are going to put high pressure hydraulic fluid (that is explosive when in a high pressure mist) through it in an engine bay remember!
bks, even a fool could weld something up....as I've proven many timesTo EVEN attempt it I would need to see the qualifications and training records of the "coded welder" who was going to attempt it, I would then insist on a 200% pressure test and an x-ray inspection of 100% of the weld, otherwise FORGET IT.
You are going to put high pressure hydraulic fluid (that is explosive when in a high pressure mist) through it in an engine bay remember!
The steel hoses would burst before even my welds !
if you are going to bronze weld there may well be coating on the fitting and the pipe so file down to get down to clean steel. Fitting as pic. As you have around 1700psi you properly only need single wire hose compression fitting should be fine but really depends if the steel pipe is designed for them ie correct size and wall thickness any way good luck. Richard
Re weld/ braze hyd fittings I have seen many flange fittings and threaded fittings simply brazed or welded the secret is proper prep to ensure zero inclusions in the joint . The stuff I'm talking about was on heavy excavation or lifting gear with pressures up to 450 bar never saw one fail in 20 years or so but saw many crimped or swaged hoes blow
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