F-gas training. So I'm over at Viva Training @vivatrainingUK [ Ссылка ] and we've got Robin here. Robin, he's been an F gas trainer or a refrigerant trainer now or working with refrigerants for about 50 years so he's really experienced in it. So without further ado, let's go over to Robin. Basic refrigeration system here at a training centre and we're going to fit some gauges to it so that we can analyse it. First thing we do is remove the valve caps. In my right hand here is the high pressure side, left hand is the low pressure side. Gauge manifold set made by Testo It's a 550i, this one. Basic manifold set but there's no readings on it so I'll have to use an app on my phone. Red hose on the right hand side against this red knob goes on the high pressure side. Low pressure side goes on this one and that's the blue hose.
How do I know which goes on which side? High pressure side, low pressure side. High pressure side, the pipe work is smaller. This is leaving the receiver down the liquid line through a dryer, a sight glass, a solenoid valve all the way up to the evaporator through the metron device and returns back after the evaporator down the suction line into the low pressure side and the compressor which then compressor goes back into the condenser and the receiver. The low pressure side always has the larger pipes and the high pressure side has smaller pipes. You get told the exact reasons for that on the training course. We'll go into the Testo app and the probes are paired already. There's no pressure showing yet because there's no pressure in these lines.
What these lines contain is air and I need to get rid of that so that it don't go into the system. I need to make sure that there is nowhere where refrigerant can escape to atmosphere because the main course of all this is the F gas cores. The reason for the F gas cores is fluorinated refrigerants and the control of damage to the environment. That's the important part of this course. I can open the high pressure side first which has now come down this line and is passed through here.
And I can purge a tiny little bit out to blow it to atmosphere and there's no air in these lines now so I can't damage my system. And there's now pressures reading on the app.
Okay we're running pressures on both sides of the system. The low side is reading 5.17 bar and the high side is reading 11.7, 11.8 bar. So we have the system working.
Compressor is compressing it. Condense is condensing the refrigerant where it turns into a liquid down the liquid line through the metering device, through the evaporator and back to the compressor.
All running nicely. Now we'll fit the probe so we can read the temperature of the lines and compare that to the pressure temperature relationship.
One on the suction line and one on the condensate return out of the condenser.
So we've now got pressure, evaporating temperature, the actual physical temperature of the pipe and then the degree of super-eaten subcoolant. Probes are all fitted, we've got a nice set of readings from the system so we can now move on to the next step of an F gas course which would be imagining there is something wrong with the system and we need to remove the refrigerant. We're now going to break into the system. That means removing all the refrigerant, we call it refrigerant recovery. It's as though there's something wrong and a component's got to be removed. So what we do is connect up a recovery unit and a cylinder.
A gauge manifold is connected as it was before. So we now have this unit down here that we turn on and it sucks basically very similar to another fridge system and takes all the refrigerant out.
What we're looking for is to get the system down on a slightly negative pressure so that when we remove the lines and we remove any components, no refrigerant will be released to atmosphere. Remember, the whole point to the F gas course is to protect the environment from the release of refrigerants.
So now we've done a, removed all the refrigerant.
Remember we removed the refrigerant because we were assuming something had to be repaired. So we can now again assume that we've done the repair and we now need to pressure test the system. So to pressure test this system we use nitrogen which is just out of camera shot here but
I can connect the equipment up.
We have to decide with the nitrogen what pressure we're going to pressure test it to.
And the pressure test
