M20 x 130mm Continuous Thread Stud Bolt Two Heavy Hex Nuts ASME B18.31.1 Flange Stud Set

This M20 x 130mm stud bolt is delivered as one complete flange joint set: a continuous thread stud plus two ASME heavy hex nuts. It is the make-up pattern used on petrochemical and thermal power piping, where every flanged joint relies on a stud passing through both flanges, a gasket between them, and a heavy hex nut on each side.

• Gasket change without breaking the joint apart. When a spiral wound or ring joint gasket has to be replaced, the nuts are backed off, the flanges are spread by a few millimetres, the old gasket is slipped out and the new one slipped in. The studs remain threaded through both flanges, so the joint is re-closed on the same studs.
• Valve swap without dismantling the equipment body. Line valves are handled the same way. The studs act as a guide rail that keeps the flanges aligned and supports the valve while it is lifted out, so the pipeline and the connected equipment body never have to be cut or dismantled.
• No thread damage to the flange. Because nothing is screwed into or out of the flange itself, the bolt holes stay clean and the joint can be re-torqued as many times as the turnaround schedule requires.

1. Clean the stud threads and apply the supplied anti-seize before make-up.
2. Insert the stud through both flange holes and fit one heavy hex nut finger tight on each side.
3. Bring the joint to the specified torque in a star pattern, then re-torque after the first thermal cycle.
4. For gasket or valve replacement, release the nuts evenly and slide the component out along the studs.

Each lot is checked for thread gauge fit with go and no-go gauges, chemistry by spectrometer, tensile and hardness by sampling, and surface finish by visual and coating thickness check. Mill test certificates to EN 10204 3.1 are issued with every shipment on request.

One stud and two nuts are packed as a matched set in a poly bag, 25 sets to a carton, cartons stacked on plywood pallets with anti-rust paper between layers. Stock sizes ship within 7 days; production quantities within 15 to 25 days.

Tell us the stud diameter, length, pressure class and the medium in the line, and we will quote the matching stud grade and nut grade as a complete set.