XP2i does it again!

Gary was away recently so I took a call from Peter at a Local Civil Construction company Hick Bros which are developing a new subdivision just outside Orewa up here in the big smoke.

They had been told they should be using a Crystal logger – Sale done! whats your order number – but after talking for a few more minutes – this sounded interesting so I said I would come up and demonstrate the unit and leave it with them – So yesterday I took Gary’s truck up and went for a 4WD drive over the subdivision. They were installing a water ring main for the subdivision and needed to pressure test it. Nothing new here.

But what had happened recently is the local water supply company was telling them they needed to start recording the pressure results and send them the results. Still nothing too new here. All this is done with ease with the Crystal XP2i Datalogger.

So I replaced their old 63mm gauge with a 70 bar XP2i and started logging at 10 second intervals. Like all people that first come into contact with the XP2i Datalogger they where impressed on how easy it was to set up and use – Hold the units button down and start logging. As you can see from the photo not much really to see – but underground there is 500 meters of water main pipe. So they had to do a 30 minute pressure test at 1400 kPa and log the results and send them to the local water supply company for sign off.

So the first interesting thing to happen, is that they talked about how the XP2i would tell them if they had a leak or it was just air in the system – A leak would show as a constant pressure drop which is very easy to see – The pressure drops at a constant rate.

Air in the system, pipe expansion (and adiabatic effect) would be a leveling out of graph as the pressure starts to stabilize and settle.

As you can see there is a very visual difference between the two graphs. Only a highly sensitive and accurate digital gauge will show these two differing pressure, so the user can decide if they have a leak or its just the pressure changing and settling.

So by looking at the graphs you can decide what is happening and then by shutting off parts of the pipework you can work out what section the leak is in. If the leak rate drop changes as you open and shut valves you can work out quickly where the leak is in the system.

After about an hour onsite it got interesting, they had to do a bounce test – they install the XP2i half way along the water main and drop the pressure at the end away from the pressure source, drop it to 400 kPa and then close the valve, the pressure will drop and then slowly increase as the pipe contracts again and the pressure equalizes across the system. Again due to the accuracy and sensitivity of the XP2i, allows this test do be done – as all this is happening the pressure is being recorded remotely by the XP2i internally for later download directly into excel.

What I thought was just a simple pressure test, was a whole lot more and the testing now being done, has been developed due to the XP2i and its capabilities.

At the end of this what really is the big benefit from all this – time saving . The water supply company guy only has to come out for 15 mins and witness the test , not 3 hours watching a pressure gauge measure the whole pressure test – just think how much more he can get done each day. As you can see from my other blog I posted recently on how good these things actually are , the results the water company gets sent from site to site can be compared to each other this is because the XP2i’s and all the other Crystal products are that accurate, Gives them confidence that the results are the same and accurate regardless of which gauge did the data-logging– that is another blog for another time.

At CPS we have a number of these XP2i which we rent out every day so if you would like to trial one or just need one for a one off test then contact us.

Leave a Reply

Your email address will not be published. Required fields are marked *