Quick question re Washer on S30 valve cap

[Pete1978 UK]

Hi guys, I have an S30 valve on my pressure pump but recently had issues with it leaking. When I am setting it up and tightening up the valve (Spanner) onto the cap there comes a point that the washer underneath 'crimps up' or is forced out from under the valve.
To avoid this I am tightening by hand but I feel this is not secure enough especially as it's loose enough that when I spin the CO2 canister it can spin the nut.

Can you give advice on how you secure the washer (the washer between the valve and cap) Without The crimping or forcing out I am experiencing? Thanks

 

[Ozarks Mountain Brewery]

try to find a harder type of silicone washer that wont spin out when tightening, or to keep silicone washers from doing that don't tighten the side with the washer, draw the washer in from the other side

 

[Pete1978 UK]

Thanks for replying. Can you let me know if you have the washer on the outside of the barrel or underneath the cap beer side? I currently have it beer side but looking at some images it seems it should be outside. Can someone confirm for me? Thanks

 

[Ozarks Mountain Brewery]

for a weld-less fitting like yours I put my washer on the inside but it works either way, the reason is I don't want wart or beer to hide in the space between the wall and the washer, I know its not a big area but can still develop bacteria in the right circumstance