6 replies to this topic

[MorrisBetter]

Hello all,

I am new to this forum, but I am in the middle of a class project and have hit a bit of a snag. I am looking for any information on the use of flexible metal connectors (metal hoses or expansion joints) in a petrochemical plant or oil refinery. I have had a very tough time finding anything on these connectors, and any information you guys have would be much appreciated!

Brandon Morris

[Art Montemayor]

Brandon:

You have to be specific. What, specifically, do you want to know about flexible metal hoses? I have used them since 1960, and I have thousands of stories about them. There are also literally thousands of suppliers, so I can’t begin to understand what you mean by: “I have had a very tough time finding anything on these connectors”.

I tried Google and got over 700,000 hits in 0.2 seconds – and my computer is over 7 years old! I’m afraid you are doing something wrong, or you are not communicating correctly.

[MorrisBetter]

Art,

I am looking for specific permanent applications and locations for these connectors. Such as: process lines for specific chemicals, gas injection lines, decoking lines, etc. Instances where the use of a metal hose is necessary and cannot be substituted for rubber, composite, or rigid piping would also be valuable to me.

When I said "I have had a very tough time finding anything on these connectors" I meant that I cannot find application specifics. All that I find is a list of "applications" that will state something along the lines of "steam transfer" or "process lines". I would like to find out what the process lines are conveying and where the steam hoses might be located.

I am not interested in suppliers, just situations that necessitate flexible metal components. Any of your "thousands of stories" would be a great resource for my project.

Brandon

[AZIZ_MN]

Hi morris,
i'm not aware of using matal hoses for permanent applications,matalic stailess steel hoses are temporary solution for any hydrocarbon or chlorinated hydrocarbon process fluid equipment or long distance line where dicomissioning facilities are not provided,so to decomission from that equipment or lines to dicomissioning vessel matalic hoses are being used(after doing full safety analyses and distance between where hose connection to be made and operating pressure of system) steam hose or rubber hoses are not suitable for some solvant kind of hydrocarbon fluid or cholrinated hydrocarbon fluid as it has tendency to meltdown the rubber so it is unsafe to use them for these purpose

correct me if i'm wrong pls bare with my english

Edited by azzu, 26 June 2012 - 03:55 PM.

[JMW]

Perhaps an application in instrumentation is appropriate?
The Solartron (now Micromotion) 7845 and 7835 tube density meters use three ply stainless steel bellows to isolate the measurement tube from the external pipework.
The sensors measure density as a function of the resonant frequency. This necessitates that the tube ends are not constrained and that as temperature changes longitudinal stresses are not imposed on the tube.
As I recall, a similar arrangement is found in the Gravitrol force balance density measurement method which uses a U tube connected to the procss lines using bellows which allow the U tube to sag under its own weight (and the weight of the fluid inside) and density is a function of the restoring force.

[kkala]

I think another possible application of metal hoses is at the jetty (pier) of a large chemical factory, loading or unloading liquid products. Concerning a local refinery I have observed a lot of rubber hoses at the jetty, either connecting the steel lines to ships or connecting two pipes. The latter occurs when the two pipes can carry different products from time to time, e.g. a central pipe and many branch pipes. They do not want an all time permanent connection on these lines (central to branches) because (a) there may be leakages between them (and resulting product contamination) (β) the connections will be complicated. A rubber hose could do the job for every loading / unloading, that is in a permanent up to 48 hour basis.
Design pressure of these jetty lines is 10 barg, versus a deign pressure of 10-12 barg reported for rubber hoses at ambient temperature. There are jetty lines of up to 20 barg design pressure in other refineries, according to our info. In this case of higher pressures, one would have to use metallic hoses instead of rubber hoses.

[MorrisBetter]

Thanks for the help everyone. I appreciate it. If you have any more information please share it. This has all been good, but I could always use more.

Brandon