How to trace a gas leak

[IK1]

Hi,



What is the best method to trace a gas leak. Obviously a tightness test would have been done showing a pressure drop and joints checked with LDF but no sign of a leak and also appliances checked to make sure they are not letting by gas. What is the next action that would be taken?

Thanks in advance for your help

 

[diamondgas]

It depends on how big a leak you're looking for, where pipework is situated, and whether the customer has smelt gas anywhere to be honest!

 

[tamz]

What is the next action that would be taken?

Look harder

 

[IK1]

Thanks diamondgas.

The reason I am asking is because when I was assisting a gas engineer we came across a pressure drop on the tightness test of approximately 6mb on an existing installation with a U6 meter. To trace the gas leak we used a gas sniffer and found that the cooker was leaking gas and was easy to identify using a gas sniffer. The cooker was ID and then replaced.However if a gas sniffer wasn't available with a similar drop and the leak was in the pipework (let assume the pipework is behind kitchen cupboards) and there was a smell of gas (assuming by smell the leak could not be found).

1) How would the gas leak be identified? And what would be used to identify it?

2) if the leak couldn't be identified and was assumed to be under floored tiling would you simply re do the pipework rather than ripping the floor up?

Btw I am due to take my ACS exams in a couple of weeks so trying to increase my knowledge but haven't really found an answer to the above scenario which I have made up.

Anyone aware of what type of trace and repair a gas leak situation would come up in the practical accessment?

Thanks again in advance

 

[IK1]

Tamz, assuming I have looked super hard and still can't find it? Then?

 

[tamz]

Tamz, assuming I have looked super hard and still can't find it? Then?

Check your guage and hose.

 

[jtsplumbing]

Just have to shut off gas / cap meter issue ID notice. if can-not be found would have to repipe !!

 

[Nostrum]

Cut into the system, cap off and re-test, repeat until you can identify which section of pipework the system is in. (e.g under floor)

 

[tamz]

LDF will find a leak. A sniffer just makes life easier.
If as in your second question it was assumed to be in an un accessible place you would cut and cap to confirm and repipe if necessary.
It is not hard to find a leak on an assessment.

 

[mountainman]

I would disconnect and cap appliances then test the carcass.
If that's still leaking then cap off various sections or re-run if practical.

 

[jtsplumbing]

Lighted match & ear plugs, :angelsad2:

 

[aggis]

Start off by disconnecting the appliances one by one & testing after each.
If the customer smells gas near to an appliances, start there, or.
The easiest is the cooker, just disconnect the baronet fitting & test the installation again[ in your case the cooker was leaking] the installation would be tight.
If it isn't, the leaks else where, disconnected the next easiest appliance.
If it is still dropping with all appliances disconnected it's on the pipework or the meter.
Disconnect the meter outlet, cap off with a disc & test, if it's tight the leak is on the pipework.[if there's a smell near the meter, start here]
You've then got to start capping off at different points & testing. It's a lottery where you start capping.....

 

[diamondgas]

1) How would the gas leak be identified? And what would be used to identify it?

Other than an electronic device then LDF any joints visible. Then its a process of elimination. Isolate and test... isolate and test...etc Until it's sound! It all depends on what you're encountering. Sometimes a re-pipe is less expensive than the time it could take to trace! I'd always discuss the options with the custard. Do they want to pay for my time to trace and repair/replace?

2) if the leak couldn't be identified and was assumed to be under floored tiling would you simply re do the pipework rather than ripping the floor up?

I'd backheel personally! However if the pipe is under tiled floors I'd look for an alternative route and discuss with custard once more their options

I never make the decisions but offer the alternatives and let the custard decide! It's their home and their money they're spending

 

[mcniven]

I use Anton gas sniffer best thing if bought (not that I get much gas leaks) lol

 

[IK1]

Thank you all for the informative answers..

So if a customer decided to:

1) have the gas leak traced, what kind of price would you charge for the job, e.g per hour. Obviously fixing the problem would be extra depending on what the problem is.

2) How would re piping be charged? Just want to get an idea of how to price up this kind of job..

Thanks again to everyone, you are making my life a lot easier by sharing your expertise with me

 

[AWheating]

charge by the hour which includes fixing time. Add material costs on top.

for full repipe just the same add up labour time plus materials. your hourly rate is up to you.

 

[Nostrum]

It's funny how often price comes up as a question on here.

Price is a basic business process which can be applied to any trade or on any job. It's also fairly easy to apply:

Overheads + labour + profit = hourly rate

hourly rate + materials ( cost to them) = price

Overheads is the sum of everything you have to pay for regardless of what is used in a particular job or not. Van insurance (even if you can walk) public liability insurance (even if you don't claim) tools, diesel, van insurance, qualifications, accreditation & registrations etc.

Say that comes to £2400 a year (keeping it simple) that's £200 a month / £50 a week / £10 a day (working on 5 days a week)

Labour is what you want it to be but essentially, what you want to earn to justify the hassle of working for yourself. Let's say £100 a day to keep it simple (remember your tax) Also remember you don't get paid holidays or sick, so you need to allow for these.

Now you need to remember your running a business, not just earning a wage. The business needs money to expand or pay for the new tyres on the van etc etc So let's say you want to put £50 a day back for the business.

So £10+£100+£50 = £160 a day or £20 per hour (at 8 hrs a day) Remember in reality your unlikely to earn an hours wage for every hour you are at work a day, if your jobbing then time to travel, do quotes etc, plus office time when you get home etc

Materials generally get a mark up on them to account for travelling and arranging, warranty etc so say the gear costs you £100, you sell them for £120

Job takes 5hr's @ £20 per hour (£100) + £120 for materials £220

If the tea was awful + 5%
If there was no tea +30%
If you never want to set foot back in the house again + 50%
If she was hot -10%

Simples

That's the basic principle. Most new business's don't realise how much the overheads amount too, and if you keep track of your profit and loss you'll see if your losing or making money. You may have to adjust, or if your oblivious you'll run yourself into the ground.

That's why you'll always hear people say it never pays to be cheap, most of us know how much all these things come to so when you see combi for combi swaps advertised for £499 fitted you know they're either not 100% legit, or losing money!