They're using
Monthly mechanical single-phase mechanical pipe expander
Month length machine: YC electric intelligent CNC pipe expander
Month length machinery: use method of hydraulic pipe expander
Heat exchanger tubesheet expansion site
Grooving device in tube sheet hole [Video of double groove one-time forming operation]
Precautions for hydraulic tube expander
Month long machinery: YC three-phase electric mechanical pipe expander commissioning instructions