I moved my machine around a fair amount while installing a dimmer to reduce pump pressure. What I didn't do was check the water line to be sure it was still secure after the work was done. Fortunately, I noticed that the counter top was covered with water before it did any damage! The water line is a braided SS hose with a compression adapter on the end for the OEM Teflon line that came on Oscar, and the Teflon tubing pulled out of the compression fitting at some point during my intervention.

After replacing the compression ferrule and securing the line again, I decided to secure the connection with SS safety wire (I'm an SCCA racer, so safety wire is an ingrained part of my work ethic). I strongly suggest that anyone with a plumbed machine add this extra precaution - it would have saved me a bit of a mess and a potential disaster.



All you need is a small can of safety wire (0.032" is good, but most sizes will work here) and a safety wire pliers like this one -



I'm about to secure all my connections this way - I'll sleep better and so will Oscar!

Sounds like the tube insert was missing. Compression nut goes over the tubing then the furrule slides over the tubing and then the tube insert goes inside the tubing. The insert keeps the tube from collapsing when you tighten the fitting and compress the furrule. Once the furrule compresses over the insert it can't come off the tubing.

How do you think this would work with quick connect fittings? I have this adapter valve to supply my plumbed in Elektra:

The other end of the ⅜" tubing is a QC to NPT adapter, so I have two QC fittings to worry about.
I've not heard a lot about QC fittings coming out, but this safety feature looks like a good idea.

okmed wrote:Sounds like the tube insert was missing. Compression nut goes over the tubing then the furrule slides over the tubing and then the tube insert goes inside the tubing. The insert keeps the tube from collapsing when you tighten the fitting and compress the furrule. Once the furrule compresses over the insert it can't come off the tubing.

The tubing that comes on the original Oscar is 6mm, but the ferrules are for 1/4" tubing (about 1 /3 of a mm larger) and they don't fit in the ID without major force. I leave the inner piece out because I'm concerned about splitting or breaking the end of the tube between the tension on the inside & compression on the outside, especially since the edges of the ferrule are rather sharp & dig into the tubing a bit.

I've never had a leak or disconnection before, but safety wire will further reduce the risk. I suppose I could make a new inlet fitting for 1/4" tubing, but that's be a major fabrication from stock, and my machine tools are history since we downsized to an apartment in 2015 & I no longer have a shop.

chappcc wrote:How do you think this would work with quick connect fittings? I have this adapter valve to supply my plumbed in Elektra.The other end of the ⅜" tubing is a QC to NPT adapter, so I have two QC fittings to worry about. I've not heard a lot about QC fittings coming out, but this safety feature looks like a good idea.

I'm wiring my QC fittings too. There are only a few web posts about disconnects or leaks, and many commercial installers swear they've never had a leak after thousands of water coolers, office coffee makers etc. But it makes sense and it makes me feel better. I also love the way it looks

It's standard practice to safety wire fittings (not hoses, but the nuts themselves) on flexible braided hoses that connect to a solidly mounted mate. Secure the wire to a fixed point as protection against unscrewing from torque generated by a slight twist. The twisted wire has to be pulled and secured in the direction that tightens the connection, or it will contribute to loosening. The most common place for such failure is in SS brake hoses fitted to their street cars by amateur mechanics who think this makes them look and feel like racers. They tighten the nuts without making sure the hoses are in neutral (i.e. not twisted at all) states. Tightening the nut torques the hose clockwise, so it then sits in the nut trying to untwist in the direction that loosens the connection - and it often succeeds over time, aided by vibration.

This applies to pump and drain hoses on espresso machines too.

Why not use a 6mm compression to ¼" NPT fitting like this: http://www.ebay.com/itm/Stainless-Steel ... SwDNdV2L8B

Lazy