Hello,

Long time lurker with first post here.

Am about to change the steam boiler vacuum breaker on my GS/3 AV from the old style, to the new SMA version, part number B.2.029.

I have seen images of others doing this, but am left with a few questions, the most urgent being whether or not others have used any sealant ( Loctite etc.) or not? If yes, which type?

Is the new SMA valve directly screw-in in the existing thread or is some modification needed?

Can someone with a relatively new build machine (2022) post an image or two of the right hand side of the machine opened with the side off, so it is possible to see the routing of the PVC tubes?

Thank you in advance!

No Loctite needed, you use a copper crush to seal that connection directly against the boiler.

Understood - the crusher is LM part L100/1A?

Yep.

You can also get those crush washers here:
https://shop.hoseandfittings.com/catalo ... 00-04.html

These guys have free freight on fridays with the promo code TGIF at check out. Pretty awesome to still find that in today's economy.

Cheers!

- Jake

I think there are 3 or 4 crush washers sizes the GS3 uses, at one point I ordered about 30 of each which is pretty handy to always have them ready to go for anything that comes up.

Indeed. You've got the 1/8", 1/4" and 3/8" BSP sizes and the 6mm on the group cap for sealing the bleed port. Unfortunately hoseandfittings.com doesn't have the 6mm size, but they have all the O-rings for the group, heating elements and everything else, along with oodles of miscellaneous BSPP and BSPT fittings.

Thanks for the comments and recommendations of the seals!

Does anyone have pictures of the right hand side image of a recent serial no. machine, with the shields off? Am curious to see the routing of the PVC tubes.

Curiously, my 2 yr old MP has a silicone tube from the vac breaker and a vinyl tube from the safety. Not sure why...

Thanks for sharing!

How do you identify whether it is a PVC or vinyl tube? They look the same to me from the image.

Sorry, looking at them in daylight now those pics aren't the greatest!
In this pic you can see them both. White and flexible is the silicone, while the vinyl is clear, relatively hard and usually yellowing as it ages.