Compatibility note: adapting an RG-120 onto RG-100 pipework

The discontinued RG-100 carries DN40 ANSI 150# connections. Its replacement, the RG-120, carries DN50. On a retrofit the pipework is almost always DN40, so the RG-120 cannot be landed directly.

The FA-4050 is a machined 316 stainless reducing flange set with gaskets and fasteners, rated to 20 bar and 250 °C — comfortably beyond the RG-120's 16 bar and 200 °C limits. Fitted, it presents a DN40 face to the existing line. Two kits are required per pump, one on suction and one on discharge.

The reduction raises suction velocity. On a viscous duty near the RG-120's flow ceiling this can push NPSH required beyond what the installation provides. The adapter also adds roughly 90 mm to overall installed length per end, which may exceed the available run between existing flanges. Both need confirming against the site before the substitution is quoted.