Acceptable gas pressure drop between meter and boiler?

I,ve got a degree mechanical engineering,still call
me a fitter.

OK your a fitter. See other thread about the misuse of the word "engineer".
 
he is an excellent heating engineer.

You mean fitter, not engineer.

I disagree with you here WS

See other thread on misuse of the word "engineer".
 
Walter = plonker


Walter= Egotistical piece of diarrhoea;)

Insults galore! They have clearly lost it!
 
OK your a fitter. See other thread about the misuse
of the word "engineer".

See this thread for the misuse of the word "your".
 
If I may ask,
What problems occur if the poster has a working pressure drop of 3 bar ?.
Lets say his gas fire was connected and three gas rings were fired on the gas cooker.
I suppose if you do not ask you will never know. !
 
the 3 mbar drop doesnt make much difference,what does make a difference is the fact this is a new boiler and gas run, corgis are supposed to work to a standard and that standard is a 1 mbar drop across the system, in extreme cases of low pressure the boiler kicking in on hot water can affect the hob especially if its on low
 
OK I can see that the boiler kicking in would create a drop on the gas, and affect the cooker.
Please enlighten me on the adverse effects of under gassing.
 
OK I can see that the boiler kicking in would create
a drop on the gas, and affect the cooker.
Please enlighten me on the adverse effects of under
gassing.

Cooker on low flame, boiler kicks in, starves cooker, cooker goes out, boiler cuts out, unlit gas issues forth, fifth & sixth.
 
Interesting mantor.
Not totally convinced on your description.
At what pressure drop would a pilot light give way.
I assume the governer is working to a point. and at working at 17 mb, I ask about the deprimental point of any gas appliance.
 
Interesting mantor.
Not totally convinced on your description.
At what pressure drop would a pilot light give way.
I assume the governer is working to a point. and at
working at 17 mb, I ask about the deprimental point
of any gas appliance.

My understanding of undergassing (and I'm not qualified in gas by the way) is that it can cause flames to burn inefficienlty which in turn causes excessive carbon monoxide emmisions.

Might be a load of bollerx but that's what I have read.
 
Hi Oliver.

That was my understanding too, although I suspect it was mainly a problem with 'old fashioned' non-room-sealed boilers with simple burners.

In a modern boiler, it'll probably just mean it's not working at full efficiency, or capable of reaching full power output.

In theory it could also affect other appliances as described by mantor.
 
Hi Oliver.

That was my understanding too, although I suspect it
was mainly a problem with 'old fashioned'
non-room-sealed boilers with simple burners.

In a modern boiler, it'll probably just mean it's not
working at full efficiency, or capable of reaching
full power output.

In theory it could also affect other appliances as
described by mantor.

I see what you mean, the excessive Carbon Monoxide may not be a problem with a room sealed appliance but what about the effects that excessive pressure drop may cause with other applicances which are tee'd off the same supply.

For insatnce if a boiler was demanding more gas than was available could a gas fire on the same supply burn ineffeciently as a result?

As I say I'm not knowledgable enough to comment with any real meaning but if I run my bath taps my kitchen tap slows down, I would imagine that gas and water flow in a simlar way if you know what I mean.
 
some appliances (mainly cookers and fires) are designed to operate on a pressure of 20 mbars, the meter govenor is set at 21 mb and in theory there is 1 mb loss in the pipework,if the pressure to too low the gas wont "pull" enough air into the injectors and you then have incomplete combustion ie carbon monoxide,the danger is greater on flueless appliances as the combustion products are not removed and are then feeding the appliance with contaminated air , this is why ventilation and working pressures are important.
cheers
 
The Worcester Bosch engineer (fitter??) said the low working pressure caused the boiler to operate inefficiently, the mixture (air / gas?) would not be correct and some gas may not actually be burnt but discharge to atmosphere. This is in essence how he explained it. It appears it should never have been commissioned as the manual clearly states in a bold box not to continue until correct inlet pressure is achieved. Of course, the original fitter signed off the commissioning sheet with an indicated inlet pressure of 18mbar (which I suppose it may have been on the day?). I had a proper 'bend' count earlier. The main run to the boiler has 11 x 90 deg. bends, 1 x 45 deg. bend and 1 offset bent into the pipe. Half the run is in 28mm (with 1 x 15mm tee to gas fire), the other half is 22mm with a 15mm tee to the hob about 0.5m before the 22mm pipe meets the boiler. The total pipe run is 12m.
 
Is that "total" length? How any bends on 28mm and how many on 22mm?

Well 11 elbows, one 45 and offset, is 7 meters in length added to the 12m of pipe giving 19 metres. Say 9 metres of 22mm in all inc' elbows. 9 metres 22mm discharges 4.6 m3/hr. <u>Borderline</u>. He needs to extend in the roof void as much as possible in 28mm and take the hob right back to the meter. If he doesn't do this he is going to have to go back again.
 
On a slightly different note, Gordon, you mentioned that renewing the gas supply pipe was a significant financial element. Is this because access to the pipe run - say in the loft area - is difficult?

'Cos frankly, running a length of copper pipe is a pretty straight-forward job. (Mind you, with all these bends, it suggests an awkward job!)
 
'Cos frankly, running a length of copper pipe is a
pretty straight-forward job. (Mind you, with all
these bends, it suggests an awkward job!)

I think they are elbows rather than bends.

On a borderline job, I once upgraded the meter outlet to a 1"x28mm meter connector and ran 0.5m of 28mm pipe and replaced 2 22mm elbows with bends. Also straighted out the flexible inlet somewhat. It worked.
 
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