Let-by test using Kane 455, getting odd reading!

[Masood]

Hi All, a quick question for the Kane owners out there. I used mine to do a let-by & tightness test a couple of days ago as I'd forgotten my manometer at a customer's house, and got very odd readings.

Just cracking the ECV open really, really gently and slowly, the pressure reading on the meter jumped up from zero to 36/37 mbar, which is obviously daft on a domestic meter! Read the instructions again, carefully, tried again, and got the same results, so I went and got my U-gauge back, and got a reading of 24.5 mbar.

So, was I doing something daft, or has anyone else had a similar "surge" reading from a Kane meter?

Cheers,
Masood

 

[Dotty]

To be strictly honest Masood, I've never used that function on my Kane. I'll have a play in the week and let you know mate.

 

[Masood]

To be strictly honest Masood, I've never used that function on my Kane. I'll have a play in the week and let you know mate.

Cheers buddy. I don't use that function either, it was only because I'd left my U-Gauge behind like a muppet! I'm going to have a play on my gas meter as well, just to try and work it out..

 

[Pssst]

I think what we are talking about here is the behaviour of the meter regulator.

The pressure on the service on a domestic low pressure supply could be anything upto close on 40mbars.


Now then,if you connect your guage be it liquid or electronic the the meter outlet,it is subject to the behaviour of the meter regulator.

In a test situation no gas is being consumed at an appliance.

If you open the ecv too quickly...a good proportion of the incoming service pressure will be applied to the internal installation and it will either blow the water out of your guage if its >30mb..or register as what might be seen as high pressure on your electronic guage.

You may then report high pressure to the ESP....which will be incorrect !

If you open the ECV slowly,the regulator will sense the higher inlet pressure and also the zero consumption. The diaphragm lifts,taking the valve with it and closing off the exit port,thus locking up and preventing the installation from being subjected to the higher pressure.


For let by tests i would always use a water guage.

I fact,id always use a water guage for general tightness testing and wp measurements at meter in domestic circs.

 

[dave1]

I've got the Anton, when doing the let by and tightness I prefer my u gauge. I find the analyser jumps to much and end up fiddling around for ages to get 10mb or 20mb.

 

[CES]

I've used my Kane a few times for this and Psst is correct, its the regulator on the meter causing the surge, but I've got a release valve inline so I can adjust the mbar reading down before I start the test. Before I had it the readings were all over the place as its quite sensitive compared to a water gauge. I personally prefer my WG but sometimes I get caught short if I'm doing two or three jobs at the same time.

 

[dave1]

I've used my Kane a few times for this and Psst is correct, its the regulator on the meter causing the surge, but I've got a release valve inline so I can adjust the mbar reading down before I start the test. Before I had it the readings were all over the place as its quite sensitive compared to a water gauge. I personally prefer my WG but sometimes I get caught short if I'm doing two or three jobs at the same time.

That's funny when I was using the sprint the other day I thought this should have an inline valve to reduce pressure without having to take the hose off.

 

[CES]

That's funny when I was using the sprint the other day I thought this should have an inline valve to reduce pressure without having to take the hose off.

This is the one I have :

Anton Pressure Relief Valve | Manometers | Corgi Direct

Have a search online elsewhere as you might get it cheaper

 

[Pssst]

It also has to be remembered that if the regulator has locked up it may not be obvious and therefore instead of doing what you think is a let by test,you are actually doing a tightness test on the installation because the reg has locked up and temp isolated the ecv>reg inlet section from the test.

Its quite possible to lockup a regulator ,disconnect the inlet flex at the regulator and still observe a positive pressure on your guage attached to the meter outlet.

 

[AWheating]

i honestly can say ive never use my analyser for any pressure reading on a meter or pipework, i will have to try it out when i have some time to spare on a job to see how it handles it.

 

[dave1]

This is the one I have :

Anton Pressure Relief Valve | Manometers | Corgi Direct

Have a search online elsewhere as you might get it cheaper

Cool cheers

 

[stevetheplumber]

Cool cheers[/QUOTE
i always open the valve whilst pincing the tube end and slipping it on to the fga once the tubwe is full if its to high remove and push back on to let it out

 

[Masood]

Cheers all. I had hoped that the FGA would have some sort of pressure damping built in, so as not to be so sensitive to the initial surge. I'd also thought that opening the ECV just a crack, and very slowly, might ease the gas into the pipe. Learnt two new things today! 😱)

 

[mfgs]

I hate using my analyser for tightness testing, it constantly jumps all over the place as the readings are almost too accurate. I much prefer using a good old fashioned water guage.