Copper gaskets

[sparkatan]

When using brass to brass flare type fittings I have always used a copper (shim) gasket but it seems others are not, due to the possibility of the shim becoming displaced in the fitting. I've looked into this but can't come up with anything definitive. Some of the components provided on compressor units such as HP/LP switches with flexible lines c/w brass couplings aren't fitted with them either.
Anyone else had this?

[frank]

FSW still stock them - Flare Gasket

Code B123 - 1/4"
Code B124 - 5/16"
Code B125 - 3/8"

Etc. (Taken from the FSW catalogue)

If required, I used to flare the end of a piece of pipe and then cut the flare off.

[sparkatan]

Thanks Frank but that's not quite what i'm asking. I've always used shims either 'home made' or purchased but recently I am coming across a lot of instances where they're not being used. The question is whether they are actually needed between two brass surfaces?

[frank]

Can't say that I've come across many instances of this, but then again, my line of work didn't bring me into much contact with other peoples install work.

As old school, I always used copper gaskets between brass/brass joints.

Looking through the Climate Centre catalogue, I can see some brass fitting pictures shown without the copper gasket and some with

[redroge]

Always used to use copper flare rings good practice, some people probably don’t use them because they have not been supplied with the kit!

[Gibbo]

Carrier 30GX HXC oil pumps were brass to brass fittings with no copper gaskets from factory but many had the copper gaskets fitted when new oil pumps fitted.
Gibbo

[Tycho]

I always used the copper flare gaskets when fitting brass-brass or brass-steel.

My take on it is that they didn't start manufacturing them just because some people may like to use them ;)

2 tricks to make them stay in place:

-Dab them in a little bit of oil and stick them on the tip of the male fitting and they should stick pretty good and not be dislodged or move out of position.

-Drop them into the female fitting and use another fitting to tighten and seat the gasket before mounting in the final position.

[sparkatan]

All very interesting opinions but is there anywhere I can find a definitive answer to this?

[redroge]

If in doubt use them

[chemi-cool]

Copper is soft metal while steel and brass are hard, any tiny misalignment might cause scratches and gas leeks are inevitable.
When copper is pressed between two hard metals' it get their surface shape and seal the connection.

There are also chemicals such as Nylog which do a good seal.

[Glenn Moore]

The manufacturers of refrigeration brass flare fittings supply copper gaskets inside the box of fittings as the gasket is a requirement to get a gas tight seal when brass to brass or steel to brass fittings are used . When purchasing a few fittings at the wholesalers such as a flare connector etc the copper gaskets should be supplied as part of the fitting . It should not be necessary to purchase these gaskets separately .
Often the trade counter staff are not aware that there are gaskets in the box of connectors and the gaskets are simply discarded when all of the fittings in the box have been sold . Suppliers like Bailey Gill always supply these gaskets in a small bag in with the fittings, so always ask for them , they are part of the brass fitting not a seperate part.
The Danfoss flare / solder adaptors come with copper gaskets which have a short piece of tube with the flare gasket ring which positions the gasket to hold it in place