Smart meters / Gas

[keith with the teef]

We have just had a new smart meter, gas, installed and the question is does any one know if the gas entering your property has to be as a certain pressure? calibrated?

Our boiler has been doing its nut since the new smart one was installed. Could it be getting to much fuel?

[Les.]

Domestic gas supplies should be governed at 8″ water gauge.

Back when I was first involved, town’s gas, it was 2.5″ wg, but the advent of natural gas required burners to have smaller orifices, entrain more air to keep combustion conditions correct, and that necessitated the higher pressure of 8″ wg.

frequently other modifications to prevent the flame “lifting off the burner” and going out.

Water gauge may seem an odd “unit”, but it is very convenient when your test equipment is limited. You can make a simple U-tube manometer with a 2′ length of clear plastic and then check the pressure.

There will be a suitable test point where you remove a brass screw, fit your tube over the TP, and take a reading. The hole in the test point is very small, so you will not fill the room with gas when you remove the screw.

Easy peasy.

Les.

 

[Ed P]

Just to add a bit of irrelevant data to Les’ s comment. The old ‘Town Gas’ used to have about 60% hydrogen in it as a result of the coking process that produced the gas.  Hydrogen has a very high flame speed and this helped prevent the flame lifting off the nozzle even with low pressures. One odd-ball aspect of pure hydrogen is that it is a pig to transport, hydrogen will ‘leak’ through solid steel walls and even embrittle the steel, but this was not so much of a problem with Town Gas.

When you read about the ‘green’ hydrogen economy and all the BS about needing hydrogen powered vehicles, just remember that a very cheap fix for gas home heating would be to mix 60% green hydrogen with North Sea gas and reconstitute a new form of ‘Town Gas’. as we know exactly what would need to be changed to make each gas burner work properly. Such a mixture would be much easier and safer to transport than trying to handle pure hydrogen.

[JayCeeDee]

I got quite excited about the prospect of nitrogen mix initially and then a transition to nitrogen after seeing a YT CHAT with the Technical Director of Worcester Bosch.

The reality ( and timescale ) of it seems to be somewhat different according to THIS  British Gas article from Jan ’22, summed up by this sentence:- In fact, as you’ll see from the estimated timescales below, a boiler you buy today will probably use natural gas for all its working lifetime. ( That would be about 10 – 12 years!! )

I think that only the younger members of this Forum will see any Hydrogen fed boilers working in the homes of the general public😒😢

[Ed P]

Back to the OP. I assume that a number of properties in your area also had ‘Smart’ meters installed. If so, then it is possible that a fair quantity of air made its way into the distribution system and you may be an end of the line customer getting the full benefit of  too lean a gas mix.

If you have a gas range, you will note that the flame ‘roars’ a lot, and sometimes goes out. Your problem will eventually go away if that is the case. Hopefully it disappears before the northern return of winter takes place later this week.

[Les.]

Ed, I always had thought it was around 40% hydrogen in towns gas, so a quick look in one of my many reference books threw up a middle figure of 50%. One of the problems of traditional TG produced from coal was that 15% of carbon monoxide, which tempted many to “put their head in the gas oven”, a quite regular occurrence.

Any time a main is opened, it should always be thoroughly purged with a flame trap burner. In the case of a meter change I would hope it would be done individually at every property. Air in the line can cause flame out, followed by the property filling with gas then blowing up.

Of course today EVERY appliance should (will) be equipped with flame failure protection, so everything SHOULD be safe. But, of course —.

At the pottery factory where I was working in 1969, we had 13 individual gas fired kilns. A local contractor had been selected to carry out our towns gas to natural gas conversions. However, I was very uncertain about five of them, knowing the problems with the burners using towns gas. I made my thoughts known, and after some doubts about my views, it was considered wise to take further advice. The gas board were brought in, thought it would be OK, but decided to turn up with a large number of high pressure cylinders of natural gas, and a big three stage  governor system. The contractors in question came along and spent an afternoon concluding it could not be done. Exit stage right.

A few days later, I ventured that I though I could do it. The MD instructed the chief engineer to give me full support!

I went away, redesigned the burner quarls and drilled out all the burner nozzles. Later I redesigned the lighting up poker, which I had already realised was a problem area.

Come the big day, 100% success.

We were still under Harold Wilson’s big pay freeze. It had barely affected me, (I had still had 6 monthly rises), but after that they got bigger.

Les.

[Ed P]

The gas transmission group are replacing quite a lot of underground pipes in this area (recognisable by the bright yellow colour of the plastic pipe) and ‘roaring’ gas burners are quite a frequent occurrence. Obviously they are only doing a ‘near enough’ purge and our gas burners are set up near the lean limit. However it all settles down after a day or two.

[keith with the teef]

@ Les. TY for reply.

I have some time today and so I’m on the case of the boiler.

I had a look at it the other day and have ordered some replacements being: heat ex changer, burner and the oven bit.

Bugger gotta drain the system.

Anyway!

[Author]

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