Strange readings at the appliance...

[Darren Jackson]

Good morning all, Did a CP12 yesterday and got 26 mbar Standing & 21 mbar working pressures at the meter so all good, but then found 22 mbar on the cooker burner and also 22 mbar at the inlet of the boiler??? Never come across a higher pressure at the appliance than at the meter before, Checked it three times to make sure with my U gauge and my FGA. Anyone else come across this before? Thought it was a bit strange.

 

[ShaunCorbs]

How can you have more pressure working at the appliance when you only have 21 at the meter ?

External gas run ?

 

[Darren Jackson]

Hi Shaun, yes HOW I don't know. But you may have just answered my query. The meter was in a brick compartment accessed from a small wooden door on the outside of the building under the concrete stairs and it was a cold shaded little compartment. Whereas the pipework ran in 22mm for 4m external along the wall with the sun shining on it.

 

[ShaunCorbs]

There you go heat will rise it 3-4 mbar

Bet your working was around 20 mbar

 

[Darren Jackson]

Thanks Shaun, 35yrs in the game and still learning. It is the first time I have ever come across this before. Wonder how many other GSR folk have come across it?

 

[Gasmk1]

never come across it but always knew it was there as working on industrial you have to take temp and bariometric pressure into account when doing long tightness tests.

 

[ShaunCorbs]

Thanks Shaun, 35yrs in the game and still learning. It is the first time I have ever come across this before. Wonder how many other GSR folk have come across it?

A few and I bet they phoned transportation up saying help

 

[townfanjon]

Yep an obvious weird one , I wouldnt have got it though lol

 

[king of pipes]

I have had this quite alot you can cause a rise just by holding onto the gas supply i try and test early morning or late afternoon in the sunny weather. Kop

 

[ambrosia]

try putting a blow touch over the gas pipe when you send the apprentice to take a tightness test

 

[Chalked]

try putting a blow touch over the gas pipe when you send the apprentice to take a tightness test

I let my apprentice tightness test. Sometimes I crack a compression nut on an appliance, just to see if he's on the ball.

 

[townfanjon]

I have had this quite alot you can cause a rise just by holding onto the gas supply i try and test early morning or late afternoon in the sunny weather. Kop

Its strange , I have never had this happen , mind you , it may have something to do with the sun hardly shines up here in Yorkshire .

 

[mfgs]

Its annoying testing external gas runs in the sun.