I have a snap-on for 30 years. You can buy or even make a cheap one, lots of Youtube videos. Ebay has them for $35.00 https://www.ebay.com/itm/304592254582?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1txWD82BQSpO5rMr5kUpOBg18&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=304592254582&targetid=4580840332323346&device=c&mktype=&googleloc=&poi=&campaignid=441131611&mkgroupid=1235851352595866&rlsatarget=pla-4580840332323346&abcId=9300906&merchantid=51291&msclkid=7aeab19b263d12d5d47fd5731e906035

No real moving parts just pressure regulator, two gauges, and a fixed orifice.