Boiler Lid Clamp Modification

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artooks
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Posts: 895
Joined: Mon Mar 13, 2017 9:48 am

Boiler Lid Clamp Modification

Post by artooks »

Hi Everyone,

I have been having some problem with Mile-Hi boiler lid clamp, the main issue was when I first purchase the boiler, there was only a silicone gasket, which I did not use since day 1 instead I purchased
PTFE Sheet ( 0.250" natural virgin PTFE sheet 12" X 12" ) to cut a gasket out of it, I made some trials at home before deciding which thickness I would need, the problem is if I used the same thickness as the silicone gasket it
wobbles because there is a gap that needs to be filled, so the best fit was 0.25" thickness, after I get the sheet and cut it out in a 2D router I get myself a PTFE gasket for my boiler, when ı first put the clamp on I immediately
realised that the thickness caused a little bit of height where the clamp barely aligns so then the screw on the clamp was pushed farther away from its initial point when using a PTFE gasket over Silicone, anyway I started using it like that, first the inside of the clamp has rough edges which does not help to sit properly, second the bridges that connects the three parts of the clamp made of thin material which has a huge play at both ends, also I got myself stripped screw problem a few times because it does not align well with the other end where it buckles and the screw tends to move upward where it gets stripped after a few uses, also It leaked steam during a run so I decided to make some big changes, I inspected all of the parts, and decided to fabricate some of the weak parts it has, I wanted to share this so maybe it could help someone who has a similar problem.

First I cut out the thin pins that connects the three parts of the clamp, the pins that were used on these bridges were 4mm rivets, I drilled 5mm holes on the three parts of the clamps and used 5mm rivets which made it more durable and strong with a minimum play, also I fabricated the bridges from 3mm thick SS because the ones that were on the clamp were 1 mm thick and during bolting this made the other side of the arm to slide upwards and strip the screw gradually.

Then I saw that there were very rough edges inside the clamp I carve some metal out in an angle so that it helps to sit on the lid much better, which it did.

The main problem was the main 8 mm bolt where it starts to lean upwards once I start to screw it in, so I decided to fabricate the housing from 3mm SS and changed the size of the nut from 8 to 10 mm also I used double nut one goes inside the housing one remains at the other ends, this also helped me to align the bolt perfectly to the other end, but I had to make the end of the 10 mm bolt to 8 mm and also make it like a ball shaped in a lathe machine, so now it sits much better.

I took me some time to do all this modifications but at the end it is worthed and I can now it for many years to come, also did testing in some runs with no leak or screw stripping what so ever.
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