Dial Washer

Do all watches have dial washer?

I recently acquired an Omega Seamaster 30, case ref 135.007, cal 286. It's in good condition, runs good, definitely appears have been serviced before but not manhandled. Upon disassembly, I see that there's no dial washer between the hours wheel and the dial.

I found a video from the Watch Repair Channel servicing an Omega from similar era, a different caliber/case but also no dial washer, which he added when putting the watch back together, at 2:00 and 17:15:
Another video I found is from Wristwatch Revival's channel, this time also a Seamaser 30 with caliber 286, also no dial washer upon disassembly, at 4:45:
How can I find out whether the watch is suppose to have a dial washer (and if so, what's the part number/spec)? The chance of all 3 watches all missing dial washer from prior services seems low?

A post here also with dial washer missing: https://omegaforums.net/threads/service-omega-seamaster-ref-2937-3-cal-267.11900/

I found the parts list for caliber 286, and dial washer is not listed there. But I'm not sure if that means it doesn't need one, or just the dial washer isn't listed in the movement's parts list, but rather in case's (which I wasn't able to find for 135.007 or similar).

Thanks!

As far as I know, back in the days, all watches had the dial washers.
Today it is a different history since there are some watches that the dial has some tape unifying the dial with the movement.

As archer said not all watches. When you have a date plate that keeps your hour wheel in place it's no use. the only use of a dial washer is to press the hour wheel down buy filling the gap between the hour wheel and dial. some tape???

My bad. I saw the word "dial washer" and thought that they were the legs of the dial that fix the movement, hence the tape since some don't have those legs.

Actually I didn't knew the use of it but thank you for teaching me as well.

Yes sometimes people put adhesive dots when the dials feet are missing instead of replacing them. It's the "easy way". It has nothing to see with the dial washer. Adhesive dots don't replace them I mean.