Help F GAS

[Gary Gun]

Can someone explain to me the proccess of replacing a compressor , including all required paperwork under the Gas Regulations ? (im going through my Fgas course and have been given some test questions). Cheers

[Gary Gun]

sorry F gas

[G unit]

OKydoky, power down, hook up gauges(4 way) to service valves, recovery unit> recovery cylinder>scales and vac pump. B4 cracking any valves on the condenser unit pull a vacuum on your gauge line by opening all the valves on your manifold and revovery unit, this shouldn't take long and if u have an empty recovery cylinder it would be recomended to open the bottle valve to vac the bottle also. Once u are happy your gauge line and bottle are in vacuum, close off the vac line on your manifold, and place the recovery bottle on ur scales(remembering to zero once settled). You are now ready to open the service valves on the condenser unit. Once the initial rush of gas from the system> into the vacuumed space of the recovery bottle has been achieved, the system gas pressure should equalise and start to show on the recovery unit built in gauges, now is a good time to start the recovery unit. You should now be observing a drop in system pressure and an increase in bottle tare weight. Once your gauges start to show the system in partial vacuum it is time to back flush your gauge line, keeping the recovery unit running> front seat service valves> close off HP, LP & service valves on gauges> close suction valve of recovery unit and carry out recovery unit purge, once recovery unit pressure is negative, shut bottle valve, turn off unit and note the final weight of what has been removed. Now ready to start the compressor removal process. Remove the recovery unit from service line to ur manifold and attach ur manifold to a nitrogen regulator. introduce nitrogen to bring system pressure slightly above 0bar, remembering to purge the service line b4 opening the manifold> service valves, this ensures that positive pressure is maintained when the system is eventually open to atmosphere. You now have the option to undo a flare, cut the pipe work or sweat the joints out using oxy-acetylene. If u are cutting into the pipework, remember to turn off the nitrogen and vent it off before cutting or unflaring, but as soon as the cut has been made it is imperitive that the open end of system pipework is sealed (electrical tape) as air ingress needs to be avoided. If u have to sweat out the joints, then u will need to (get a hot works permit?!) maintain a low pressure trickle of nitrogen( to prevent oxides forming), by removing one of your gauge line and vent the nitrogen out. once your are ready to start hot works, a bit of flux around the brazed joint may help, gradually apply heat to the joint( remember to wet rag any valves that are near to the heat). Once the joint begins to glow, with your free hand, equiped with a glove and a pair of pipe grips, begin to ease the joint apart. Once presented with the foul stench of burnt oil, u have separated the pipework, allow the two ends to cool( accelerate the process if needs be( damp rag) and repeat the process on the other side of the compressor. Once the pipework is free, undo the compressor mounts, remove any electrical connections ( making note of where they go), remove crankcase heater if fitted, and then pull out the compressor.
Remember to cap off any open pipework.
If ur working with shraeders, ie split a/c, u will have to work off ur ball valves on the hose lines
:confused: lots of clag involved

[Brian_UK]

Apart from 6 months behind the original post I think he would be hard pushed to get that answer into the test paper answer box. ;)

Mind you, ever heard of a paragraph? :D