Segmented Seal Rings

Carbon/graphite is the ideal material for steam turbine packing rings, and ROC Carbon is the perfect source for high-performance segmented seal rings. Our rings feature precision manufacturing and special material grades for optimum sealing performance and service life.


Carbon/graphite grades used are from our Group C graphite and Group F carbon/graphite materials. These grades have a fine-grain structure with excellent mechanical properties. Retaining (or "garter") springs are made from Inconel (for temperatures above 700° F) or stainless steel. Stops are made from cadmium-plated steel or bronze.

Precision manufacturing

Sealing effectiveness of ROC Carbon turbine rings is achieved by a combination of careful design and painstaking craftsmanship in manufacturing. Shaft clearance calculations take into account the coefficient of thermal expansion of both the shaft material and the selected carbon/graphite grade as well as the exact operating temperature. Typical segment ends are either overlap or light-tight butt joints, and each joint is matched and marked. Ring faces are given a commercial lap finish.


ROC Carbon maintains an extensive inventory of the most popular packing ring styles. Nonstandard and obsolete parts can be manufactured and delivered in 10 working days for routine orders. Emergency orders can often be shipped in a day or less.

Instant OEM part cross referencing

Over the past 40 years, we have compiled a comprehensive database of 20,000 cross reference part numbers. If you can supply model number or OEM part number, we can quickly determine the correct ROC part number and respond with a quote or ship the part immediately if it is in stock.

Technical services

ROC Carbon’s engineering staff is available to help you evaluate seal problems and to recommend solutions involving seal geometry and material. For nonstandard parts for modified machines, we will recommend the proper turbine ring ID if you furnish steam conditions and shaft size.

To order

For original equipment replacement parts, please furnish the OEM part number or the specifications of the machine. For custom-designed parts, we are pleased to furnish drawings. If you wish, we will design a seal for you. For fastest response, call our toll-free number: