Hopefully people will be back later.
I'd still be demanding an answer to the basic first question. They either can or can't reconnect the supply for now. If not why not.
In an ideal world we'd be there with cameras and equipment reporting more fully on the situation.
That is an ambition for the new Gas-News to ease my frustration at not being able to do more sat on a chair.
Amazing. Just sorry I can not help with any information. What contact I have had with suppliers has often been frustrating, both gas & water. Perhaps this is due to the current practice of using intermediaries so the lines become blurred.
I am still not clear EXACTLY WHAT NG consider to be wrong with the service pipes they insist on replacing. If it is simply age, they may contend that the condition of the unseen (and therefore un-inspectable) parts of the (steel) pipes make replacement mandatory. But IF the visible bits are in good order AND there is NO history of leaks in the building AND there are no special circumstances, the whole issue seems to have gone completely out of control!
I doubt whether 'polymer filling' is really an option in this case.
I have only seen it used when an underground service pipe is repaired by inserting a plastic (MDPE) pipe inside an existing steel pipe. The insert is a relatively loose fit and the polymer fills the gap and in effect creates a 'composite' pipe.
Inside a building, there are likely to be acute bends which would effectively prevent insertion of the inner pipe.
Succinctly put. You need the status quo in writing immediately. If they will not, assume they dare not.
Thank you all for the posts. An update since I got back.
NG has amazingly inferred (I use this word in lieu of a more accurate one, but this is a public blog) to the regulator that they have spoken to our managing agents and everyone is happy. We believe that no such contact took place.
At the moment we are being outflanked, with NG delaying dealing with us while cutting a deal with our neighbours. As I type a team is digging up the road to restore the supply to next door, while another team is putting a pipe through the basement flat to the rear of their building. That pipe will then feed the building from a surface mounted pipe running up the rear elevation. Once in place the idea will be to feed the flats in our building and then, I suspect, every building in the row.
I have been receiving emails on this as well off the forum. I do not know how much I can safely reveal of the content therefore I will not reveal any at this time.
As an aside, a concern relating to all this was referred to by one of our professional visitors. This relates to the location of any new meter, relative to the location of the current meter.
In other words, if the length of pipe from the meter [on your side] is greater than it was before, there may be a risk in some cases [or none at all], that the dynamics of each system could be affected.
Each case would have to be considered on individual merit. Many factors can affect this so I do not want to be too dogmatic.
A simple before and after test would resolve that question in each case. I would absolutely insist on such a test or, documentation confirming pipe sizing has been properly considered.
I think NG must actually have 'implied' whilst the Regulator may (or may not) have 'inferred' - but that's just pedantry :=)
I'm still in the dark about the technical background to all this....... WHY were the service pipe(s) and / or in-building pipe-runs found unsatisfactory? HOW? and based on WHO's judgement?
I really don't think it's reasonable to imply wrongdoing on NG's part without some further explanation. OTOH, if NG has failed to explain it's findings and conclusions in a technically accurate and complete manner, it has no basis for any (off-the-record?) briefing of the Regulator (and the Regulator obviously knows that perfectly well!).
You may have missed some of the history but the essence [and allegation] is that NG have steadfastly refused to explain themselves.
As I've said before I'd encourage co-operation with their role but I would never be blackmailed into submission by anyone.
I'll check tomorrow what else I can report that I am holding information on.
Humble as we are, we are not a tabloid and I don't want to thwart the reasonable efforts of the offended parties.
"explain its findings" if you do want to pedantic John!
I understood that replacing internal service pipework to blocks of flats had been given a high priory under the general "swapout" program agreed with the HSE.
Certainly around here much of the high rise have new service pipework running up the outside and many of the non council blocks have also had the work done. Typically pipes enter through the wall at the back of kitchen units (where the meter can be relocated) and if there is insufficient space the meters are kept at ground level.
The quality of work leaves much to be desired. Sleeves are often unsealed (or non existant), meters not on brackets and internal gaspipe woefully undersized. One of the worst (on a council high rise) was the connection from the new meter position under the sink onto the existing gas carcass. 22mm run through the kitchen units and tee'd into the cooker bayonet wall elbow. The gas pipework to the boiler was now undersized and the cooker bayonet outlet had been refitted in such a way to prevent the hose hanging in its previous U shape (actually under significant strain).
As usual the work is contracted out through so many levels that only the inept and incompetent undertake the work so no suprise with poor quality. The management at the top level hav'nt a clue whats going on and didn't care either the last time I pursued it.
In an ideal world we need someone on the spot down there [SW1] recording facts for a before and after appraisal.
What's good for the goose is good for the gander.
I've seen plenty of those bang, thump, wallop and out efforts as described.
XXXXXXX came over today to have a look at the situation. Coincidentally a NG contractor was around as well, so we were able to discuss the problem and for once I was with someone who understood the technicalities. It appears that the initial leak was in an iron main and having replaced that, NG would not then attach the new pipe to the iron pipe work leading to the meters within building. This is law or policy or both. It all sounded very plausible but I was still left with some nagging doubts. Obviously these arose after XXXXXXX’s departure and so I emailed him. Below is a copy of that email in case anyone else would like to comment.
Thank you very much for coming round, it was much appreciated. As predicted, a couple of afterthoughts:
1. Presumably when the pipes to the meters were installed 20 odd years ago NG/Tranco or their forerunner took responsibility for those pipes as sited at the time. I would have thought that NG now have an inherited responsibility and just because of the cost of replacing those pipes in situ would be high they have abdicated that responsibility. I think we are going to have to get chapter and verse on their actions.
2. Having thought about it, I do not see why they did not just make a temporary fix with the pipes and then put the gun to our heads and say that the fix was temporary and that a new solution would have to be found within x days as they would then turn the gas off.
3. The failure of anyone at NG, and I mean senior to Robert Stamp, to communicate with us smacks of evasion. It would have been quite easy for them to produce documentation for why they are doing what they are doing. I may be thinking that there is a conspiracy where there is not one but it does make we wonder by what authority they are taking the action they are and have we really been given all the options. Had the basement flat owner of No. 81 refused to allow the pipe to run through his property what would they have done then?
4. When I asked Geoff why they could not just reconnect the pipe work he stated that it was 'illegal'. Therefore the action is not 'best practice' but a contravention of the 'Gas Act of 19XX'. This must be publicly available and we can look at it with our lawyers.
That is it for now.
Thank you again.
These pipes are SERVICE pipes, between street main and meters. They are therefore presumably owned (as part of the assets of the company) by NG. Since they are a necessary component of the DISTRIBUTION system, I can't see how NG can play ducks and drakes with the ownership of the pipes depending on whether they are an asset or a liability at the time!
I imagine that the justification for this whole matter is that NG current practice is to 'retire' steel pipes (NOT 'iron'!) after a number of years. OK - but AFAIK that does not include any automatic right to pass replacement costs onto the users of the gas supply. If it DOES (chapter & verse, anyone?), then we are in for a LOT of grief. There must be thousands of miles of steel service pipes from street mains to meters. 'Retirement' day must be looming up for most of them!
The buildings in question.
Gas-News now has a full set of images and a chronology of events in SW1, including statements from people affected.
Enquiries are still in progress at OFGEM and elsewhere before we can present details of what is certainly a matter in dispute.
From the evidence we have, it is unlikely anyone would argue about the need for improvements. What matters to us is how the matter has been handled by the authorities.
We live in a democracy.
As it happens, I just came across a 'streetful' of gas subcontractors on a distribution main replacement project.
According to the gaffer, ALL cast-iron street mains and ALL steel service pipes to meters are being replaced in a long-term programme. The process consists of digging out the street connections, pushing a MDPE liner into the service pipe, sealing it in, remaking the connection to the (steel or cast-iron) main, 'one-waying' the main, pushing a MDPE liner down that, reinstating the double-end-feed for the main, breaking / cutting (as appropriate) the main at each connection point and then remaking the MDPE/MDPE joint again.
Only WELDED steel pipe is to continue, apparently.
I was (obviously) vaguely aware of main replacements going on but as far as I know, there has been NO publication of the plan(s), NO information via TGI or otherwise to the gas installers and NO statement about liability for the cost. No-one has ever directly informed ME (an RGI)of any aspect of this work.
One important reason RGIs MUST be informed is the possibility (probability!) that some / many of the sleeving operations will push pipe-scale, sulphide dust, etc, along towards the building, increasing the risk of some getting carried into the meter and appliances. Black Dust is ALREADY a big problem and we need to be made aware of increased risk of pressure-loss and blockages. (Presumably if main-replacement work introduces contamination into an appliance so it needs costly repairs, NG should pay!)
As far as I know, there's no question of individual householders being hit with bills for sleeving service pipes. Therefore, for reasons of 'equal treatment', I can't see how NG or anyone else can bill ANY customer for work on life-expired service pipes, even if they do live in a mansion-block.
I now understand, or at least think I understand, what NG are trying to do and why. While they would like to dispense with iron/steel pipe work from the main to the meter, NG have not demonstrated their right to do so. I would have thought that it would be a fairly straightforward process and would serve us with a fait acompli, forcing us to accept their decision. I would like to know firstly, under what authority this action is being carried out and secondly, I want access to that authority so that I can establish its legitimacy. NG’s actions so far have been to stonewall all our attempts to get answers to our questions. Given that no one seems to have been notified of this new policy it does sound suspicious. If they can do this often enough then it will become established practice without any challenge.
As the picture above shows, the building is a standard central London house, the majority of which have been converted into flats. There must be thousands, if not tens of thousands of such buildings in London alone, and eventually they will all be subject to this work.
I don't think there's any suggestion that the owners of the flats will be asked for any money JohnB. There is compensation (£30/day up to £1k) for non supply of gas, which would cover the direct cost of using electricity say. (Though the same figure would be used for a large house where it might well not be enough)
I would like to know firstly, under what authority this action is being carried out and secondly, I want access to that authority so that I can establish its legitimacy. NG’s actions so far have been to stonewall all our attempts to get answers to our questions.
Sounds like an issue that your MP might like to get his teeth into. Certainly they have the clout to ask questions in the right places, and get answers for you.
Further, I still think there's mileage in looking up and boning up on their statutory obligation to provide a gas supply. There must BE one or they'd just disconnect whenever maintaining the supply gets awkward for them!
I am now in a position to answer a few questions and will do so later.
Just working on another site at the moment, plus the new Gas-News site.
OFGEM and Energy Watch have been most forthcoming today. I give credit where it is due and today it is.
NG can simply state they they do not reconnect ferrous pipes once they have found leaks, having done a Risk Assessment based on their experience. The policy may be restricted to certain building types, quite reasonably. They are after all the experts in that. I can't see Offpipe or the HSE suggesting they should take greater risks.
Ever tried asking a Taxi driver for proof of the authorisation he has for choosing his route?
NG can't quite show you a door, but surely it is they who control which of their pipes they use to carry the gas?
Technically the policy is certainly worthy of questioning. There must be many variables, such as the age of the existing service pipe, the route it takes into the building, the type of failure which caused the leak, and so on. I wouldn't be surprised if a policy which makes eminently good sense in one situation is bewilderingly inept in another, which may look similar at first. As soon as part of the pipe run is out of sight though, there is doubt.
The stunning part here appears to be the ineffectiveness of NG in conveying the information, from an appropriate level in the organisation, to all concerned, individually. This IS common a gas supply situation, so where are the leaflets, the contact numbers, the PR machine?
John and Chris are 100% on the nail as usual. But let me tell you that is going to change in SW1.
The cost relating to gas mains can sometimes be influenced by historical factors. This may apply where a Landlord has agreed to fund some parts of mains into a property.
At one development I’m aware of, the main was routed to a communal meter store and the landlord paid for pipes from the meters. Routine stuff of course. In another situation the gas main may be routed nearer to flats [and the meter], to reduce pipe sizing from the meter.
Those extra bits of main may [or may not] be funded by the landlord.
I use the term landlord loosely. It could also apply to owner-occupied [leasehold] flats where a service charge is applied to properties. In such cases, the home owners will be aware [or should be] of their obligations, when purchasing a property. That includes roofing and landscaping etc. It may also include some gas.
We’re involved with a shared ownership scheme at the moment where the owners can only buy 80% of the equity for reasons of service charges [flats]. The homes on the same site can be purchased outright eventually.
OFGEM supplied us with the following PDF today: Editor - link removed This link will disappear next week and the PDF will reappear permanently in a website news story [The name of the PDF I’ve altered for convenience].
Whilst NG have certain powers, they also have obligations. That aspect will be fleshed out next week in detail. We want the whole truth to be publicised and it will be publicised for the benefit of others, arriving from www searches, once the pages propogate around the www.
We have lots of images, text, emails and testimony to process which will take time.
Energy Watch will be exploring all aspects of regulatory matters for our delectation, not just rights-of-entry, and will be taking a close look at SW1 in particular.
There is more but it would be appropriate to leave that until the full picture has been revealed.
Perhaps this will give a little more info
Yeah, but no, but....
This is the right background for the street-main replacement programme - thanks for that. CORGI never bothered to mention it!!!
Issues discussed here relate ONLY to STEEL pipes, NOT 'iron' (unless, of course, we've been misinformed and the service pipes are in fact iron (impossible, I'd have thought...)).
Rumour remains that although SGN is, it seems, under no pressure from HSE to replace steel pipes, this is being done anyway, as part of the iron-main replacement. Note that ANY steel service pipe that is NOT pretty-much a straight run from street-main to elbow up to meter will be 'a problem' using the current (observed) procedure.
We were discussing this programme today, which is generally known in the industry.
My gut instinct - not usually wrong - is that there is a general 'understanding' to keep a low profile, with regard to the gullible masses. If true we'll do what we can to correct that.
They have a massive and challenging task but that does not excuse corporate bullying and maladministration, if that's what we are looking at.
Apologies for the delay but I've been wrestling with my RCD. Following several bangs, resets and re-boots I finally saw the flames emerging from behind the freezer. Must have been a fault in the integral plug. My rib-eyes are now safe.
It's difficult to know whether distinctions are relevant.
The pipes in question in SW1 feed only a converted house or two, so are service pipes, not the main running the length of the street.
One man's iron is another man's steel. They both corrode, which I believe would be the basic problem.
Without getting into my ledeburites and Widmanstätten structures:
The element iron doesn't have any carbon in it, though like pure water, it's a rare commodity. More than a couple of percent carbon makes it Cast Iron. LESS than than and it's called Steel, which is confusing. The carbon in steel is there to make it stronger, loosely, and is generally a bad thing for corrosion resistance.
The stuff we make cars and I would guess "barrel" pipe out of, is very low carbon, not far off "wrought Iron" which ideally has no carbon at all. The "milder" the steel, the less carbon.
The only difference which I think would be relevant to gas pipes is that if you bash cast iron with a hammer (whether the "ductile" version or not) it'll be much more likely to break, than mild steel.
What might be more relevant in this case is what covering, plating, dipping or other surface treatment the particular pipe may have or have had. External corrosion seems to me to be the only significant issue.
Internal surface corrosion of a steel gas pipe is unlikely to be significant. Gas-tightness of threaded couplings and other fittings may be an issue - but should not be, whatever the age. Cracks or splits due to flaws or inclusions also seems an insignificant risk for steel pipe.
If its steel underground, it's most unlikely to be completely untreated. But we have no specific information.
Once inside the building above ground, corrosion is also unlikely to be significant, even if the pipe is bare steel. But I must also comment that I have encountered bare-steel (water) pipes in damp (wet!) cellars that were in a fairly shocking state!
So once again, we are still on the key questions: what risk is NG actually addressing by insisting on pipe replacement? and does this risk actually exist in this case?
(Another question is why National Grid is involved here, rather than Southern Gas Networks?)
Does the risk exist? The whole point is, that nobody knows.
It seems that given the uncertainty, they won't re-use.
Several installation procedures (may )have changed over the years - sleeving, corrosion protection, venting in ducts, proximity of other services, and on and on.
So it's only worth addressing the question of the continued serviceability of the pipe if it's ALL visible.
If all the statutory undertakings (gas, electricity, water, main drainage, phone, LA Building Control, ...) go down this track, the result will be utter chaos and spiralling costs to all concerned with NO clear limit!
At some point, the geniuses who bang-on about 'risk-assessments' and 'safety-cases' will have to learn to get their hands dirty and ACTUALLY assess REAL risks, on (or in) the ground, rather than sitting in Ivory Towers pontificating and dreaming up ever-more-unlikely what-if scenarios.
Present situation is already Complete B-S!! The CI-main replacement technique is ALREADY to stuff a MDPE liner up the service pipe and seal it in, without ANY regard for what happens immediately beyond the end of the MDPE. I doubt that the contractors are actually entering the properties, let alone doing a real inspection. It's only when it's evident that there are multiple meters on the end of a single service pipe that a (different) 'risk' box is ticked - but NOT as a result of any real assessment.
In the single-meter situation, there is ALREADY a serious risk: although gas pipes are not SUPPOSED to be used as electrical earths, many are still providing a 'path to earth'. This is why RGIs mess about with earth jumper cables when disconnecting meters, no other reason! Put in the MDPE liner and smash out the CI main, and the earth-path has GONE - but who's doing anything about that? No-one!
I suggest this approach is nonsensical.
Having had a look at the pics of the 'suspect' pipes available elsewhere on Gas News, I now understand the problem a bit better.
Evidently, the service pipes from the main into the building are in the 'usual' state for Central London - a tangled mess! A lot of this stuff may even be pre-WW2, so it's hardly surprising that National Grid / Southern Gas Networks / ... are 'concerned' about restoring supplies.
Although one of the pictures is captioned 'Corroding pipes' I wouldn't judge what is actually shown to be automatically 'unsafe' due to corrosion. If there is indeed no sleeving through walls, that's a different matter entirely. It would then be impossible to judge the pipe condition inside the wall and it would have to be condemned.
Given the geography and the (regulatory!) requirement to deliver 20mB of gas pressure to ALL the separate flats, the supplier has a problem which (presumably) can only be solved by putting a service pipe straight through the building and then up the outside of the back wall, with meters and ECVs properly re-positioned in each flat.
I doubt very much that there is any effective solution based on meters at ground level, outside.
Only question then is what's stopping NG from getting on with it? Is there no practical route? No wayleave from affected leaseholder(s)? Or is NG trying to extract payment? If so, on what grounds?
Ironically I posted about a corroding pipe earlier this year and have just found the posting. In that situation the pipes were outside and accessible. Nevertheless I condemned them as AR [At Risk] and served notice on the RSL accordingly.
That decision was entirely subjective of course but the priority has to be safety of the people living round about. Nothing in it for me as I was there as a building surveyor on a dilapidations survey. You may therefore rule out pecuniary interest on my part.
Those homes are clad with curling shiplap timber boarding, known to be draughty. Therefore convection currents pull air in from outside and could easily pull in gas if a pipe leaked.
Failure of the pipe shown above is inevitable if neglected. That is a fact no one can dispute. We can of course argue about the rate of decay.
As someone on the forum eloquently pointed out recently, the problem with describing the above pipe as NCS [Not to Current Standards] is that the RSL do not have to do anything about it. And indeed they probably will not until it leaks. In one ear and out of the other.
The next step is AR but that requires me to switch off the gas, label and issue a notice, which in that case I did not do. I just served notice.
What is patently missing is a 30 day notice. Without a smell of gas immediate shut off in that situation seems excessive. All in all a moral and ethical dilemma.
The images from SW1 appear to show a hefty copper pipe entering the hidden areas. Nevertheless, I’d be concerned about the ferrous bits if I was living there.
The chronology refers to the options for improvement and that suggests the situation is a complex one.
There is no doubt in my mind that some sort of dedicated liaison officer is required moving from site to site, where the situation is complex as it clearly is in SW1.
The copper pipe is output from the meter and therefore of no concern to the gas supplier! It does appear unsleeved - which is a problem for the leasholder / landlord.
The input is T'ed off a 1.5 or 2-inch steel pipe, which is also apparently unsleeved and by definition 'unsafe'.
As the chronology shows, there have been a couple of suggestions and refusals. An aerial pic of the address (google or LiveLocal) shows it to be one of those inaccessible rear aspects. Which means that an awful lot of scaffolding will have to be passed, doubtless in short lengths, through the building.
Then it has to be erected the seven floors.
We're 4 weeks and counting, who would bet they'd be finished before another two or three? That is too long. I would have thought it worth some work, say to make a reconnection downstream from the leak, to be tested every day or two until the pipe is replaced. It's not like they're going very far.
I think that's a sleeve on the pipe from the meter, only
We have received some links from Energy Watch which will be incorporated into a website story in due course but you may want the links now:
HSE info on mains replacement:
Gas Distribution Price Control Review document:
The Gas Safety (Rights of Entry) Regulations 1996:
Recent email to Institution of Gas Engineers & Managers:
There seems to be a major and increasingly-widespread problem with gas pressure at domestic gas installations in UK.
Part of the difficulty is that gas suppliers want meters that are easily accessible - for example,
wall-mounted outside the building.
At the same time, the cast-iron main replacement programme rolls on and there are repeated instances where the distributor declines to reconnect the old (steel) service pipe (often serving multiple meters inside multi-dwelling buildings) to the new main.
Taken together, the final effect is to move large numbers of meters nearer to the street - and further away from the appliances served. This poses serious or insurmountable problems for gas installers attempting to meet STATUTORY requirements to deliver 20mB +/- 1mB to the appliance. Without infeasibly-large gas pipes between meter and appliance, this often can't be done!
Already, CORGI has been obliged to include 35mm copper tube in the 'domestic' category. This has safety consequences: obviously (?) as pipe diameter and static system volume increases, there have to changes to tight-ness testing and especially to purging requirements. There WILL be safety issues due to inexperience and ignorance amongst installers.
Time, I suggest, for IGE to make clear its position on this and put forward suggested solution(s). Ever-larger diameters for internal pipe runs is not a realistic candidate! Perhaps UK should follow United Arab Emirates (I kid you not!) and introduce TWO stages of pressure-management- one governor at the meter and a second one at the entrance to the premises. Using an intermediate pressure of (say) 30mB
would make no practical difference to metering accuracy and would resolve probably 95% of pipework pressure-loss issues.
I'm a member of the Association of Registered Gas Installers. Members are increasingly exasperated at being left with little support and no solutions from the 'powers that be'.
Some observations on the posting by John Brooks.
Firstly, the correct operating pressure at the meter outlet should be 21mbar +/- 2 mbar.
Secondly, the inclusion of 35mm copper pipe is to accommodate the increased load placed upon domestic supplies by high gas input combi boilers. The installation problems this will create are vast. The consequences of trying to run this diameter of pipe in notches through joists without breaking the requirements of the Building Regulations is a significant problem.
Thirdly, we have had limited use of medium pressure gas services to domestic properties for some time now, a move that eliminates pressure and volume problems but increases the leakage risk due to the gas in the service being at 2 bar pressure. I understand that discussion has taken place concerning the possibility of increasing the pressure on a low pressure gas service to 50mbar, a move which would resolve the pressure problems being experienced in some parts of the country. After all, the pressure in the gas mains under the roads is 75 mbar anyway.
The only draw back to increasing the pressure would be a potential increase in leakage rates.
As a final observation, the latest BS 6400-1, states that as well as a meter outlet pressure range of between 19 & 21 mbar (21 +/- 2), there could be as much as 4 mbar pressure absorption through the meter itself resulting in 15mbar of pressure being available at an appliance. Forotunately or unfortunately, depending on the way you lok at it, appliance manufacturers especially the ones making combi boilers are not too worried if the pressure at their appliances burners drops as low as 13 mbar.
Just how impressed a customer who has purchased a high input, high hot water delivery boiler will be, is open to speculation.
And my response:
I NEVER mentioned 'pressure at the meter outlet' - I ONLY referred to the standard requirement for 20mB at the appliance. It is THAT that cause problems, especially when the meter has been moved to the street-side for the convenience of the gas supplier / meter reader.
I do SO agree that 35mm tube is usually an inappropriate size for practical installation within a building, especially under floors. What do YOU suggest, instead?
The street pressure makes not a hap'worth of difference to the situation downstream from a meter governor set to deliver 21mB +/- 2mB at the meter outlet, UNLESS there's a problem with an undersized / partially-blocked service pipe. This is not nearly so common as low pressure AT THE APPLIANCE caused by internal pipework issues. The street pressure is emphatically NOT always up to 75mB and often significantly lower.
Does BS6400-1 REALLY say that pressure absorbtion WITHIN the meter affects pressure at the outlet??? Why? Surely the governor (upstream from the meter) would actually be set higher to compensate for any drop within the meter?
It is incorrect to suggest that a WP down to 13mB is 'OK'. A big combi with a zero-pressure governor on a premix burner is probably SAFE to operate at that pressure. What's going to happen that could be 'unsafe'? The real problems are that it probably won't actually reach its rated max heat output and gas rate, and will be burning VERY lean at high power levels. What happens after several years operating like that? - you tell me. And what's the point of encouraging installers to measure Benchmark figures that will inevitably be 'wrong', quite apart from what the customer might think about the actual value of his purchase?
The 'gas industry' and gas distributors / suppliers in particular must meet industry and BS standards for the product delivered, in terms of Wobbe number, calorific value AND working pressure!
Recent ACS included the same 4mbar possible drop in the meter. So you could have 19 - 4 - 1 = 14mbar. NB this is at full load so you can't adjust the reg.
I looked up meter mfr BS years ago, and it said 2mbar then. 2mbar more (droop) is in the regulator I suppose.
Maybe we need oval pipes?..
And thus it was suggested on my ACS, which warned us to expect significant dips in pressure at certain times due to demand but of course (of course) no useful formula to help us decide which dips we could be certain were due to demand and which due to a dodgy govenor / meter.
I suppose all we could do is call back at intervals, perhaps at 02.00 and repeat the test, but who’s going to pay for that. All part of the deliberate and unsettling confusion.
As the eminent C.H. Rolph once wrote:
The vagueness is the product of a vague mind or the sophistry of a devious mind, ready to change (as circumstances require) while maintaining that nothing has changed.
That wonderfully sums up the regime.
My advice. If it drops below 19, dial the numbers, call it in and make a note that you have done so. As it is a 0800 number use the punter’s phone, not the mobile.
I don't understand how pressure drop through the meter can be a factor if the installation is set up to give 21 mbar (+/- 2 mbar) at the meter outlet on maximum demand. Meter pressure drop is a problem for the gas supplier/transporter, not the consumer. Isn't it their responsibility to provide 21 mbar at the meter outlet up to the maximum capacity of the meter?
It emerges at 21 plus or minus but the drop (presumably constant) is allowed for. Thus if the meter offered no resistence, the pressure would be 25 plus or minus and would have to be screwed back.
On one block of flats I had a shed-load of old meters, many of which were changed. One TRANSCO guy told a punter he'd have been better off if I'd not called it in as the old meter was delivering more gas for his ££ - Should have reported him.
By the way, one meter change there I dialled the numbers and it was sub-contracted to A, who'd sub-contracted to B, who'd gone belly-up and vans snatched back that morning. Hence the engineer arrived in a hired van, with a new (on paper) employer and apologies for delay - Fascinating.
Just had this yesterday from Ideal boilers, news letter Issue 5, July 2007. one of 10 most popular questions.
Quote: What is the minimum working inlet pressure for an Ideal Icos/Isar?
Answer:Although the gas regulations state that you require 20 mbar working pressure on the gas inlet to a boiler, due to the fan arrangement on the Icos/Isar the gas is under negative pressure and therefore as long as you have a pressure of over 14mbar you will have the correct gas rate, unquote.
Rewriting the rules? Will check what mi says later.
Off to install waste disposal unit, yes I have a part p lecky in the back of the van as we speak, so all cushty, or should my customer be composting tea bags etc not grinding them up and flushing them down the drain, Greener? Can’t win!
Yes strange how meter losses have suddenly burst onto the scene. I completed my CCN1 reassessment today and one of the questions was "What is the lowest acceptable pressure at point 'A'?" (Point 'A' being shown as the outlet elbow on a diagram of a meter.)
The correct answer is now 15mbar. I'm SURE it was 19mbar on my last assessment!
Pressure loss across a meter of up to 4mbar is now acceptable, apparently. Knock off the 1 mbar pipework loss that's allowed between meter outlet and appliance inlet, and what a coincidence.. there's the 14mbar Ideal say the Icos/Isar needs.
Now thats not in the book! Is it? More on that later. Not the answer I got when I phoned Corgi 2 years ago. Have to go off to chase Polish electrician. True, the wires are wired up Polish stile Blue is live Brown is nuetral. Yuck.
Mike Bryant wrote "The correct answer is now 15mbar."
Who says? There's enough confusing misinformation around without any of us posting stuff without identifying the source. If no one will put there name to such claims, and be willing to substantiate them, then let's ignore them, please.
This uncertainty about 'available' Working Pressure below 20mB both AT THE METER AND AT THE APPLIANCE is madness! I really DON'T CARE what figure is 'acceptable' from manufacturer X for boiler model Y, when the moon is full and it's a Monday!
The bottom line is the worst case - a conventional burner in an open flue boiler when the MI says '20mB +/- 1mB'. And there ARE some examples of pretty-much this requirement. I'm definitely NOT going to be the fall guy who goes to jail when CORGI et al melt away like snow in Spring instead of SUPPORTING RGIs!
It's time this issue got PERMANENTLY nailed, with additional expensive technical solutions if necessary.
Try visiting the situation from a different perspective. I nearly said problem but it is not a problem.
The book says 21 + or – 2 and that is what I stick to. Anything outside that and I dial the numbers. If anyone in authority wants to disagree or grumble, let them. But that’s all they’ll do.
Some ACS lecturers are clearly trying to massage the truth to help their mates or former mates working in organisations with an interest in these issues. Not only do we know it but we can taste it. It also helps maintain the confusion with younger elements.
If I get a letter from CORGI or their masters the HSE suggesting a different protocol then I’ll insert it into my new CORGI loose-leaf handbook (when we get one) and adopt that.
Otherwise neither CORGI nor the HSE will interfere with any decision made by a RGI. I guarantee it. They are inherently risk-averse anyway.
Now it is nailed permanently.
Les said "Some ACS lecturers are clearly trying to massage the truth... It also helps maintain the confusion with younger elements."
Creating and maintaining confusion is of course very much in their interests. The more "confused" we are (thanks to their efforts) the stronger their argument for better (more) training and assessment.
It's a vicious circle where the profusion of assessments creates confusion and the impression of incompetence among operatives, hence the apparent need for more training and assessment.
Les is absolutely right to identify our need to focus on what the regulations actually say and require, and to disregard the rest.