gas appliances

**murdock** · 15-Jul-11, 07:29 PM

i went to look into getting a gas geyser today...i was told that i had to use a approved gas installer...i dont understand why i must pay a person to come to my house screw a gas geyser onto the wall...then connect it to the bottle... i do this literally every week when i change my bottles.

what does it take for me to become the 30 001 st authourised installer in south africa?

**Justloadit** · 16-Jul-11, 11:49 AM

Hi Murdock,

When it comes to gas, there is much more than meets the eye.

As a simple example, a copper pipe may not touch the wall that it is going through or going along on, as there could be some corrosion taking place causing a gas leak. Certain types of metals may not be used in the installation due to chemical reactions. There must be blow back valves installed, to ensure that oxygen never gets into the system, and others. I am not aware of all the regulations, but did do this inquiry some time ago, so I may not have all the facts right now. I do remember that there many things I thought trivial, but on deeper thought realised the danger that may be exposed.

There is a very stringent set of regulations governing this, as one mistake can cause a huge explosion.

**murdock** · 16-Jul-11, 02:50 PM

sounds like i need to do my homework properly....maybe i should do what people do with the electrical installations.

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.

**AndyD** · 16-Jul-11, 11:07 PM

Originally Posted by murdock

sounds like i need to do my homework properly....maybe i should do what people do with the electrical installations.

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.

Sounds like you'll be doing the job twice and paying the qualified Gas guy twice for doing nothing. What happens if he uses your own technique and issues you a failur notice with just references to the regs and no explanation?

**Dave A** · 18-Jul-11, 09:22 PM

Originally Posted by murdock

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** · 18-Jul-11, 11:55 PM

Originally Posted by Dave A

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.

**Dave A** · 19-Jul-11, 11:35 AM

Originally Posted by AndyD

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.

**Justloadit** · 16-Jul-11, 05:30 PM

Sounds like a good working plain ;>)

**murdock** · 17-Jul-11, 10:10 AM

i did some research and found a place where i can do a 4 day course on gas installations...lpgas.co.za...after reading up on the dangers...eeeeeish maybe just do it right first time...next step is to get a gas leak solution to check joints and couplers...cost R50...but at the end of the day better safe than sorry.

i think people take gas for granted...until something goes wrong...i have a little more respect for the stuff now that i know a little better.

**Justloadit** · 17-Jul-11, 10:44 AM

Hi Murdock,

Have a friend who was burnt quite badly by a gas leak, so yes, it is not forgiving.
I also suggest you invest in a permanent gas leak detector/alarm as a precaution.

Unfortunately whilst electricity may be dangerous, a protruding wire, whilst dangerous, is more forgiving than your kitchen floor covered in gas and you have a spark.

Gas is extremely violent and explosive when there is large amounts of it. The temperature can rise instantaneously to about 800 degrees centigrade when mixed with oxygen and it gets lit.

Another simple but effective way to detect leaks, is to add soap to water and use a paint brush to paint the mixture over joints. A gas leak will cause bubbles to form .