Allen screw size on MCDONNELL & MILLER 67 blow down valve

Old_Steam

Can anyone advise the size Allen key needed for the Allen head cap screws on the MCDONNELL & MILLER 67 blow down valve body? I have to remove some p[arts to get to it, and i want to make sure i have the right socket before i get into it.

Thanks

109A_5

I believe it is 1/4 Inch. Stand by I'll check.

109A_5

Yes, 1/4 Inch Hex. I checked the screws on my boiler and my spare stock.

109A_5

I believe they have been shipping the units for decades with the 1/4 Inch hex drive cap screws. Yet the manual as of 2019 still refers to the old flat head screws.

Steamhead

I've seen both flathead and Allen screws in the field.

Old_Steam

https://forum.heatinghelp.com/discussion/comment/1890911#Comment_1890911

Thanks brother