Forbes Marshall supplies SIB 45 Sealed Inverted Bucket Traps. Forbes Marshall is an ISO 9001 certified company. The SIB 45 Sealed Inverted Bucket Traps is an all stainless steel sealed inverted bucket steam trap provided with pressure change assemblies for pressure differentials between 0.5 and 45 bar. Traps for 45 bar are provided with an inbuilt check valve as standard in the SIB 45 Sealed Inverted Bucket Traps.