Manway cover studs and nuts, handhole and inspection port cover bolting, support pad studs and anchor bolts are the kinds of parts we make in Houston, to your drawings and specifications.
A generic recirculating U-tube steam generator of a pressurised water reactor, about 68 feet tall: a channel head with a divider plate and two primary nozzles, a 21-1/2 inch tube sheet, a bundle of U-tubes held by seven support plates, a lower shell, a transition cone and an upper shell with the moisture separators. The pressure boundary is welded and does not come apart, so it is opened the way an outage inspection opens it: the primary manway nuts spin off and the covers, insert plates and gaskets come away, then the secondary manway covers, the handhole covers and the inspection port covers. The support bolting under the channel head is shown last. The bolting is in colour. Press Solid view for a steel model, or Cutaway to see the channel head, tube sheet, tube bundle and separators inside.
Twenty 1-1/2 in. × 10 in. studs in tapped holes round each of the two 16-inch manways in the channel head, each with one nut. They clamp the cover and its stainless insert plate onto a spiral-wound gasket. Typically SA-540 B24 or SA-193 B7.
1-1/2 in.-8N × 9 in. studs holding the covers on the two 16-inch manways in the upper shell. Twenty per manway is typical.
1 in.-8N × 6 in. studs holding the covers on the two 6-inch handholes just above the tube sheet, on opposite sides of the lower shell. Twelve per handhole is typical.
Four small studs and nuts on each 2-inch inspection port in the lower shell. Size and count are typical.
Fasten the cap of each pinned support column to a pad under the channel head. Four per column, shown at 1-1/2 in.; the support design sets the size and count.
Cast into the floor and up through each column base plate, with a washer and heavy hex nut. Size and count are typical.
Manway, handhole and support bolting, made to your drawings and specifications. Send us your drawings and material spec.
Request a quote832-446-3442A generic steam generator, not any maker's or any plant's design. The manway and handhole sizes, the twenty primary manway studs, the stud sizes, the tube sheet thickness, the tube size and the shell diameters come from public documents. Wall thicknesses, nozzle sizes, pads, covers and bolt circles, the secondary manway, handhole and inspection port stud counts, the supports and their bolting, and all bolting materials are typical or illustrative, and the tube bundle is representative (far fewer tubes than a real unit). The nozzles are welded, so they carry no bolting. Quality and code requirements for parts like these are set by the purchaser's specification. Your drawings govern. We manufacture to your drawings and specifications.
Drawn from public regulator training material and public technical reports on U-tube steam generators; stud sizes and materials are those named in public regulator notices and repair summaries.
© 2026 Innovation Fasteners. This interactive drawing, its 3D models and its code may not be copied, hosted elsewhere, scraped or used to train AI models. Terms of use.