Anyone playing with high pressure ?

electrokid · Post by **electrokid** » Mon Jul 12, 2010 5:18 pm

You may have noticed eleswhere on this forum my intention to monitor HP pump pressure on the dash.

I'm going to split the HP pipe - pump to regulator - and put in a tee - the 500 bar specified components finally arrived today. Into the 'third' port on the tee I'm going to fit a pressure transducer but before doing that I will need to test the pipe itself - hopefully to a reasonable 'margin of safety' - hopefully 250 bar or so. I have a blanking plug for the third port to allow this to happen because the transducer is only spec'd to 200 bar which is fine for the BX but not for the pipe test.

So... is anyone playing with this sort of pressure and perhaps has already built a jig for some similar purpose ? Or if anyone knows of a test house who specialise in HP ?

I know it's a long shot - but if there's something out there which will save me some time building the jig myself...

Cheers,
Brian.

MULLEY · Post by **MULLEY** » Mon Jul 12, 2010 5:39 pm

Is the idea of monitoring the pressure because you want to see the health of the pump?

Vanny · Post by **Vanny** » Mon Jul 12, 2010 6:46 pm

The way we do this in the lab at work is pretty simple, a partly milled out piece of aluminium (to make a chamber) with an 'in' and 'out' port machined into either end. Another tap machined in to take a pressure sensor, and a piece of perspex bolted down over the chamber. This allows you to see fluid flow. This chambers are made by hand in Japan.

I could sketch it but not give you an actual picture.

On cars we do something similar without the chamber and with calibrated pressure sensors.

I think the best (simplest way) would be to take a three way union from a BX, make a new short pipe, take the feed from the pump to the FDV into the three way, then the short piece from three way to the FDV, then either a gauge (think ebay, any hydraulic gauge with suitable range) or hydraulic pressure sensor on the final output of the three way. I would opt for the sensor and perhaps a small computer based data logger?

electrokid · Post by **electrokid** » Mon Jul 12, 2010 10:24 pm

because you want to see the health of the pump?

My thoughts exactly - mind you, the amount it was pumping out onto the road on Saturday - I don't think I need to worry about for a while yet

I think the best (simplest way) would be to take a three way union from a BX, make a new short pipe, take the feed from the pump to the FDV into the three way, then the short piece from three way to the FDV, then either a gauge (think ebay, any hydraulic gauge with suitable range) or hydraulic pressure sensor on the final output of the three way.

That's along the lines I'm thinking about - thanks for filling in some of the detail for me. I already have some gauges with FSD of 4000 psi (but you're right - they probably came from eBay

)

If I do it myself I'll be using uncalibrated gauges but I'll be using 'retrospective' checks on their calibration. I'll run the pipe with the blanking plug as high as I can reasonably get it - 250 bar will do - then remove the blanking plug and fit the sensor - which has a calibration guarantee - and run it up to the max for the sensor - 200 bar and check that the reading on the gauge tallies with the sensor output - that will be a calibration check on the gauge I just used ! Using a sensor instead of a gauge is a good idea - but they're not cheap.

citronut · Post by **citronut** » Mon Jul 12, 2010 10:26 pm

or you could speak to Martin at Pleiades on 01487 831239, as he over hauls citroen hydraulic components, he is in Sawtry Cambs PE28 5SB

regards malcolm

electrokid · Post by **electrokid** » Mon Jul 12, 2010 10:48 pm

Hi Malcolm,
I chatted with him briefly today - ordered some seals to put in the spares box - he may be able to help but probably if i need some pipework custom made rather than the testing stage - they are out of 1/4" pipe at the moment but I managed to order a couple of pipes from a local Citroën dealer - they are still available from the factory. I also ordered some Y pieces for the top of the reservoir (mine is crumbled) - they come in packs of 2 anyway so I'll have some spares to offer on BXClub since the requirement comes up fairly regularly.

citronut · Post by **citronut** » Tue Jul 13, 2010 7:50 am

ok Brian

i think the rubber three way union on the sub frame behind the battery, might be better to use for the tank breather as it is a T not a Y, there for the pipes conected to it will lay flatter,

regards malcolm

Vanny · Post by **Vanny** » Tue Jul 13, 2010 9:21 am

If you want a brass 3 way for 3.5?mm pipe then let me know and I'll bring one with. I can probably supply you some 4.6?mm pipe up to a metre, and unions but i don't have a huge amount left.

I buy my pipe from Bonepart 2CV if they are still trading (was considering wrapping up), but it is just kunifer pipe and i think the larger bore is a standard size for 'normal' brakes so you might be able to get it off the shelf at a factors.

Does this mean pleiades are looking to do business again? Last time i contacted them they where less than interested in making a sale.

Stinkwheel · Post by **Stinkwheel** » Tue Jul 13, 2010 11:36 am

Vanny, bonaparte was sold in whole to a french company, they offer all the same services but now from french france, with an increase in price i may add.

electrokid · Post by **electrokid** » Tue Jul 13, 2010 11:55 am

Thanks for the offer Vanny - I think I'm ok for bits a pieces at the moment. I've avoided stocking any kunifer or copper in case I ever make the mistake of fitting some to a Granada - front brakes peak at around 4000 psi which can burst copper quite easily - and that would happen at the wrong moment of course

I have had an incident - overtaking 4 cars and needing to get back in quickly where a flexible burst and I didn't make it back in - fortunately the oncoming driver and I drove accurately enough to avoid each other - I'd still like that to be a one-off though

Does this mean pleiades are looking to do business again? Last time i contacted them they where less than interested in making a sale.

Martin was obviously very knowledgeable about the BX hydraulics but the quick chat we had didn't really delve too deeply into what he might or might not be able / willing to do. I'm effectively right at the start of this little project so I'm sure there's plenty of little hurdles I'm still unaware of so unable to chat in that much detail. I would guess it's always worth giving him a call if there's a hydraulics problem to be dealt with.

citronut · Post by **citronut** » Tue Jul 13, 2010 7:03 pm

Vanny wrote
"Does this mean pleiades are looking to do business again? Last time i contacted them they where less than interested in making a sale."

i know he moved his workshop to diferent premisses,

so maybe he was dealing wih that at the time,

regards malcolm

rayfenwick · Post by **rayfenwick** » Wed Jul 14, 2010 2:58 pm

electrokid wrote:I'll run the pipe with the blanking plug as high as I can reasonably get it - 250 bar will do - then remove the blanking plug and fit the sensor

I presume you'll depressurise first?

(Sorry, couldn't resist

)

Post by **mat_fenwick** » Wed Jul 14, 2010 3:14 pm

It would probably be a wise idea…

A few weeks back I had to replace an LPG solenoid in the engine bay, which should be an easy job as you can simply disconnect the solenoid on the tank to make sure the only gas that escapes is that which is in the pipe. However, if the tank solenoid is stuck open you get a stream of LPG coming out at 100+psi and at a temperature of about -40°C. Makes it damned difficult to thread the unions together without cross threading!

Carl (TB2) got some photos/video which I would imagine look quite spectacular.

electrokid · Post by **electrokid** » Thu Jul 15, 2010 9:40 am

I presume you'll depressurise first?

Yeah - I noticed not mentioning that step as soon as I'd posted

if the tank solenoid is stuck open you get a stream of LPG coming out

Something slightly similar happened to me this week - fortunately it was only a ciggie lighter - I can imagine you staggering out of the workshop covered in icicles

rayfenwick · Post by **rayfenwick** » Thu Jul 15, 2010 11:20 am

electrokid wrote: I can imagine you staggering out of the workshop covered in icicles

When I was living in Moscow, I had a workbench on the balcony, which had sliding single glazing, and the other side had IIRC 30mm gap double glazing to the flat.

We used to put beer/champagne out there to chill until the cold weather(!), When it was really cold outside it would just freeze, so we had to put it in the fridge.

Cables on drills etc would be solid, and needed to be brought into the warm or the cable risked broken insulation.

Anyway, five minutes or so hunting for tools on the balcony was quite enough in the depths of winter - it was abominably cold!