Compressor Air hose - repair or chuck away?

[sotal]

I've had my compressor for about 6 years now, it's nothing fancy just a machine mart £150 type thing.

When I got it I bought a long black hose, over the last year I've noticed that the ends of the pipe were starting to perish. Then whilst using it today with an air ratchet it started hissing. I took the ratchet off and was trying to work out where the air was coming from when suddenly the end popped off the hose (which made me jump!) Just glad I was holding both sides as it came off with some force.

Past a few cm the pipe looks fine, is it worth having the pipe cut and new ends put on? I'm guessing it's probably not worth it?

Is there any advice to stop it happening again. (am I doing anything wrong?)

I do tend to leave the compressor full of air which I know isn't recommended, and I leave the pipe full of air. I had a backup pipe which got the job finished today (one of those orange coil hoses which comes free) this time I switched the tap off at the outlet then let the air out of the pipe - is that something I should normally do?

[LandyManLuke]

I'm surprised the crimp fitting has lasted that long.

Just cut the hose back 6" or so and use a normal hose barb to 1/4" thread fitting, with a hose clip, connected to your original PCL or similar. only a quid or so.

On my smaller compressor i try to leave it empty to take the pressure off the seals, though i know many people don't bother.

The larger tank i have can be isolated with ball valves, so it's easy to leave that full and empty the hoses and regulator.

[David Sparkes]

.....

Past a few cm the pipe looks fine, is it worth having the pipe cut and new ends put on? I'm guessing it's probably not worth it?

I'd say yes, it is worth repairing. Take the hose to some shop that deals in air compressors etc and either have them do the work, or buy the appropriate crimpable clips (I forget the correct name) and DIY. Buy some spares for next time, the hose isn't obviously top quality.

Is there any advice to stop it happening again. (am I doing anything wrong?)

In my experience, this style of perishing happens to any and every hose if it's natural state is to bend at ~90 degrees after it leaves the fitting. IE, the outlet points horizontally, but the pipe bends down through gravity. My approach is to install a metal 90 degree bend into the horizontal outlet, so that it now points vertically downwards. The initial sharp bend in the hose is eliminated, and any other bend isn't as sharp, or always there, so the hose is not stressed. I style all my installations with downward pointing outlets; compressed air, oxy-acetylene, and mig-welding hoses.

Note that sharp metal bends have a negative effect on maximum airflow, the pressure dropping off as demand becomes high. Minimise this effect by using a bend in the largest diameter bore you can fit, which possibly means putting the bend straight into the tank, before the tap.

Given the standard (highly flow restrictive) tap and regulator fitted to MM / Clarke compressors, this may not be practical without replacing the tap, water trap, and regulator. Also the standard adaptors screwed into the tank tend to be sealed in with some sort of lacquer, and take some real grunt to remove. All in all you may prefer to go with the simpler 'after the tap' small bore bend.

I do tend to leave the compressor full of air which I know isn't recommended, and I leave the pipe full of air. I had a backup pipe which got the job finished today (one of those orange coil hoses which comes free) this time I switched the tap off at the outlet then let the air out of the pipe - is that something I should normally do?

Given my installation, I sometimes do empty the pipe, more often I don't.

There is a risk, made worse if you leave the hose lying all over the floor to be walked on, have things drop on it, or burn it. The risk assessment and the consequence of the subsequent decision are all yours. :-)

HTH

[sotal]

That looks like the bit that flew out.

It has a crimp on the end of the pipe which that pushed into allowing it to swivel. The ability to swivel seems useful to stop the pipe getting twisted up. I just don't fancy it popping off again.

Looking at Machine Mart it was probably this one:

http://www.machinemart.co.uk/shop/product/details/rh15-rubber-airline-hose-8mm-15-metre/path/air-line-equipment-air-hose

So at that money it's probably easy to replace, I've also seen some on reels which would be handy to keep it tidy

[LandyManLuke]

They don't swivel once they're done up anyway, least mine didn't.

I bought a load of the barbed fittings as above, and a stock of hose clips. Now, when a hose gets too leaky, I chop it up and use it for tails or shorter extensions.

[sotal]

If I chop the swivel crimp off the end, do you think that the barbed bit which flew out of the crimp would push into the pipe with a hose clip to secure? That way I haven't got to spend any pennies!

Just don't fancy the end coming off at my head!

[FridgeFreezer]

There are the basic push-fit-and-clamp type and there are the factory-crimped type. You can re-make the end if it's the first type but not the second, it must be machine crimped.

Most hydraulics & pneumatics places can crimp hoses up, but I know they will not re-end hydraulic hoses due to the high chance of future failures. I don't know what the deal is with an airline - the answer is probably either buy a new one or buy a barbed connector as pictured and repair it.

Swivelling joints are available separately if you need one.

[ejparrott]

According to our Hydraulics service engineer, re-ending of hoses is now illegal.

At work we use clear PVC reinforced airline, and Jub clips and barbed fittings for the ends. I too have one of those black hoses with the crimped ends from MM, its machine crimped, and badly perished - its now my spare. Once they start going, they fail quite frequently, you'd be better off replacing.

[boyt]

i work for a cv dealership, all we use is barbed ends and hose clips and we run at 200psi, most air tools are recommended to run at 90psi, but we have never had a problem at 200psi, from 3/8 drive air gun to 1" drive air gun

andy

[cieranc]

I'm just amazed that something from Machine Mart has lasted over a year!

One of our lads has just bought a slide hammer kit from there, used it this morning to pull a dent out. 3 hits and the screw on end flew straight off, stripping the threads.

Took it back, they said it must be misuse, said he had been slide hammering too hard.

Beggers belief.

[ejparrott]

I made my own, can pull 20mm dowels with it....

[AIRWOLF]

HI WITH RUBBER OUTER SLEVED AIRHOSE BEND THE HOSE BACK HARD ON ITS SELF AND LOOK FOR TINY CRACKS APPEARING .IF THESE APPEAR CUT MORE OFF BEFORE PUTTING ON A NEW END AS THIS INDICATES THE HOSE IS PERISHED WERE CRACKS APPEAR.

[Hybrid_From_Hell]

HI WITH RUBBER OUTER SLEVED AIRHOSE BEND THE HOSE BACK HARD ON ITS SELF AND LOOK FOR TINY CRACKS APPEARING .IF THESE APPEAR CUT MORE OFF BEFORE PUTTING ON A NEW END AS THIS INDICATES THE HOSE IS PERISHED WERE CRACKS APPEAR.

Please take note, I think that

my eyes are bleeding slightly after reading the above

Nige