gas appliances

[Justloadit]

Well Murdock,

Get yourself a couple of more certificates, and you can then charge for doing this other work to supplement your income.

[sparkydelux]

Well Lets put it this way. A chiller can hold between 150Kg and 250Kg of Refrigerant. A fridge, couple of KG, A split unit (pre charged about 3.5kg and then top up all depends on run etc.)

I said combustible and not inflammable.

I assume ammonia is not flammable?

Some Info from institutes around the world.

Definition: A refrigerant that may ignite or burn. This includes butane, propane, isobutane and certain other hydrocarbons. Flammable refrigerants are considered dangerous because of their risks to service personnel as well as the occupants.

Refrigerant is a flammable substance and is classified three ways: Class 1, Class 2 and Class 3. Refrigerant that is classified as Class 1 is considered to be non-flammable, while Class 2 has a low flammability classification. Class 3 is considered to be highly flammable.

How is this any different from LPG?

I now retract my original quote and ammend it to 'Combustible and Flammable'. Learn another new thing everyday.

[Dave A]

i will install everything then leave it for a week then call a qualified gas installer and ask him to sign it over...he will tell me what is wrong give me a quote to do the repairs...get what is required and do the changes then call him back.

From what I've seen flowing through my biz on the gas testing side, I recommend against that. I get the sense that it costs more to fix a badly done installation than to put it in properly in the first place.

And yes, I've been staggered at what prices run at for gas installation work compared to electrical work. I expect it's because there are surprisingly few suitably qualified gas installation guys out there prepared to work on domestic gas installations. I know it's been a real scramble for us to find the right guys.

I don't know about how refrigeration stacks up against gas ito standards or hazards, but there is a SANS code that has to be met with gas installations.

When it comes to gas leaks, you don't need to "sniff it out." There's a simple pressure test where you charge the system up to ?* and lock it off for ten minutes. If the pressure doesn't drop - no leaks.

*Can't remember off-hand, but it's not that high. When I get back to work I can check up for you if anyone's interested.

[AndyD]

When it comes to gas leaks, you don't need to "sniff it out." There's a simple pressure test where you charge the system up to ?* and lock it off for ten minutes. If the pressure doesn't drop - no leaks.

This is a standard 'drop test' and it's not an accurate test. With a large installation there could be hundreds of litres of gas in the pipework and even a small pressure drop over a few minutes could mean a very large leak.

With refrigeration a deep vacuum is pulled on the entire system and a similar test is done over time but when using a vacuum a small leak will be detectable far faster than using the pressurisation method. You can't use a vacuum with a gas installation because the pipework wall thickness is insufficient and the pipe will collapse.

Refrigeration engineers are often qualified to work with LPG if they are R600a or R290a certified. Lpg is used as a refrigerant in some domestic fridges nowadays.

[Sparks]

I am also a qualified refirigaration technician and do not know of any refrigeration system with inflammable gas in the system. Sweating on such a system will definately be your last job. The only danger of a refrigerator is shock. As for LPG, I have been using it for years and consider it safer and more economical financially and time-wise provided all the safety precautions are taken. I will never trade my gas hob for an electric one.

[AndyD]

I am also a qualified refirigaration technician and do not know of any refrigeration system with inflammable gas in the system. Sweating on such a system will definately be your last job.

Here's an article from 2009 about the joys of isobutane (R600a) as a refrigerant.

[Dave A]

This is a standard 'drop test' and it's not an accurate test. With a large installation there could be hundreds of litres of gas in the pipework and even a small pressure drop over a few minutes could mean a very large leak.

Agreed, although it does perfectly well on the typical domestic installation.

I guess there's a reason why there are different levels of qualification in the gas game too.

[Sparks]

I believe the original post related to a "domestic" gas geyser? The main thing is that whoever installs it needs to be a "responsible" person with safety as his main concern. Not securing a gas pipe where it is exposed to friction is not what a "responsible" person would do. My gas pipe goes through a pipe I put in the ground from the kitchen "island" all the way to the outside.