I need to make a brass plug a tight watertight but removable fit into a freeze plug hole in an engine block (fitting a block heater). The hole is 2.125". There will be about 7 psi behind the plug when hot and it will be physically retained by a toggle.
How much 'squash' do I need to build into an 'O' ring set into a groove in the plug to ensure it is watertight but also allow it to fit into the hole in the first place?
AWEM
Hi Andrew
If it is a static seal, which this one sounds like, then you should aim for around 20% crush on the 'O' ring cross section diameter, and of course make sure the seating groove will permit this. I have a link somewhere to useful info about this, I'll see if I can find it for you.
Peter
Found the link, more info here
Peter,
Excellent - just what I was looking for - many thanks
AWEM
James Walker (
With nitrile rubber 'O' rings I allow 0.75 of cord from groove base to hole side and 1.25 cord width for the groove width ( static applications ).
For this application if you can fit 2 rings of 1/16" cord a BS 033 will fit. you could also use a 3/32" cord ring, BS 138 should fit.
I find Mantek in Aldershot very useful, they hold a vast stock of rings, have a minimum order charge of only £ 2.00 and will post orders ( normally arrives in the morning post next day ). Tel 01252 343 335.
Hope this helps.
message
applications ).
Jonathan,
Many thanks for that - very helpful
AWEM
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