Gas pressure check

55Trucker

I have a Laars Mascot FT boiler. I would like to check the out pressure of the gas valve, but there is no spec for the size of the test ports. I measured the plug diameters at .1905", or almost 5mm. I am assuming that I can't just slip a neoprene tube over the test port, that I need something with a barb screwed into it? I've attached a couple of pictures of what I am talking about. Any advice that you can provide will be greatly appreciated. Thanks.

HVACNUT

The hose slips over.
Dont remove the screw. Just crack it loose to test.

55Trucker

Thank you!

EBEBRATT-Ed

Some are 1/8" pipe thread. You can get a fitting 1/8" MPT x barb