LP Regulator

Just for other interested thread followers, some of the newer 2 stage regulators are coming through with a 1/8" pipe thread plug in the upper area of the second stage area. This is so a fitting can be installed temporarily to check or adjust the actual output of the regulator. We had a regulator fail about 3 weeks ago and the new one was so equipped. When I checked the old one it was only putting out about 7" WC of pressure instead of 11" WC. And yes, I do have a gauge.

It is a Marshall horizontal 2 stage regulator. Cover for adjustment screw makes sense. Thanks

You should be installing a horizontal two stage regulator and the vent should be facing down.
Plastic cap in most cover the adjustment screw. It should be preset, so don't play with it!

Picture or part number will allow better answers.

Could be just a cover over the adjustment screw for calibrating pressure.

And, is your regulator installed VERTICALLY or HORIZONTALLY. Different PN's for each!

Also, why are you replacing a 2017 regulator-- what failed?

Not sure what regulator you have. Two stage or one? How big is the plug?