A pressure capsule/header assembly for a process fluid pressure transmitter is provided. An isolator plug has an isolation diaphragm at a first end thereof and a second end spaced from the first end. The isolator plug has a fill fluid passageway fluidically coupling the first end to the second end. A header has a first end configured to carry a pressure sensor and a second end spaced from the first end. The header has at least one electrical interconnect extending from the first end to the second end. A biaxial support ring is disposed about an outer surface of the header. The biaxial support ring and the header define a tapered interference interface therebetween. The header is welded to the isolator plug at a first weld and the biaxial support ring is welded to the isolator plug at a location that is spaced from the second end of the header.