TSI offers API ring joint gaskets in two basic types, an oval cross section and an octagonal cross section. These basic shapes are used in pressures up to 10,000 PSI. The dimensions are standardized and require specially grooved flanges.
The octagonal crosss section has a higher sealing efficiency than the oval and would be the preferred gasket. The hardness of the ring should always be less than the hardness of the flanges. Dimensions for API ring joint gaskets and grooves are covered in ANSI B.16.20 and API 6A.

Material | Designation | Max Hardness Rockwell B | Max Hardness Brinell |
---|---|---|---|
Soft Iron | D | 56 | 90 |
Low Carbon Steel | S | 68 | 120 |
4-6 Chrome | F-5 | 72 | 130 |
304 Stainless Steel | S304 | 83 | 160 |
316 Stainless Steel | S316 | 83 | 160 |
347 Stainless Steel | S347 | 83 | 160 |
410 Stainless Steel | S410 | 86 | 170 |
Size | PSI Rating | No. | Soft Iron Part No. | Stainless Part No. | Size | PSI Rating | No. | Soft Iron Part No. | Stainless Part No. | |
---|---|---|---|---|---|---|---|---|---|---|
1-13/16 | 10/20M | BX-151 | RGSTBX-151 | RGSS316BX-151 | 2-1/16 | 2000 | R-23 | RGSTR-23 | RGSS316R-23 | |
2-1/16 | 10/20M | BX-152 | RGSTBX-152 | RGSS316BX-152 | 5000 | R-24 | RGSTR-24 | RGSS316R-24 | ||
2-9/16 | 10/20M | BX-153 | RGSTBX-153 | RGSS316BX-153 | 2-9/16 | 2000 | R-26 | RGSTR-26 | RGSS316R-26 | |
3-1/16 | 10/20M | BX-154 | RGSTBX-154 | RGSS316BX-154 | 5000 | R-27 | RGSTR-27 | RGSS316R-27 | ||
4-1/16 | 10/20M | BX-155 | RGSTBX-155 | RGSS316BX-155 | 3-1/8 | 2/3000 | R-31 | RGSTR-31 | RGSS316R-31 | |
5-1/8 | 10M | BX-169 | RGSTBX-169 | RGSS316BX-169 | 5000 | R-35 | RGSTR-35 | RGSS316R-35 | ||
7-1/16 | 10/20M | BX-156 | RGSTBX-156 | RGSS316BX-156 | 4-1/16 | 2/3000 | R-37 | RGSTR-37 | RGSS316R-37 | |
9 | 10/15M | BX-157 | RGSTBX-157 | RGSS316BX-157 | 5000 | R-39 | RGSTR-39 | RGSS316R-39 | ||
11 | 10/20M | BX-158 | RGSTBX-158 | RGSS316BX-158 | 5-1/8 | 2/3000 | R-41 | RGSTR-41 | RGSS316R-41 | |
13-5/8 | 5M | BX-160 | RGSTBX-160 | RGSS316BX-160 | 5000 | R-44 | RGSTR-44 | RGSS316R-44 | ||
10/20M | BX-159 | RGSTBX-159 | RGSS316BX-159 | 7-1/16 | 2/3000 | R-45 | RGSTR-45 | RGSS316R-45 | ||
16-3/4 | 5/10M | BX-162 | RGSTBX-162 | RGSS316BX-162 | 5000 | R-46 | RGSTR-46 | RGSS316R-46 | ||
18-3/4 | 5M | BX-163 | RGSTBX-163 | RGSS316BX-163 | 9 | 2/3000 | R-49 | RGSTR-49 | RGSS316R-49 | |
18-3/4 | 10/15M | BX-164 | RGSTBX-164 | RGSS316BX-164 | 5000 | R-50 | RGSTR-50 | RGSS316R-50 | ||
21-1/4 | 5M | BX-165 | RGSTBX-165 | RGSS316BX-165 | 11 | 2/3000 | R-53 | RGSTR-53 | RGSS316R-53 | |
10M | BX-166 | RGSTBX-166 | RGSS316BX-166 | 5000 | R-54 | RGSTR-54 | RGSS316R-54 | |||
26-3/4 | 2M | BX-167 | RGSTBX-167 | RGSS316BX-167 | 13-5/8 | 2/3000 | R-57 | RGSTR-57 | RGSS316R-57 | |
26-3/4 | 3M | BX-168 | RGSTBX-168 | RGSS316BX-168 | 16-3/4 | 2000 | R-65 | RGSTR-65 | RGSS316R-65 | |
3000 | R-66 | RGSTR-66 | RGSS316R-66 | |||||||
20-3/4 | 2000 | R-73 | RGSTR-73 | RGSS316R-73 | ||||||
21-1/4 | 3000 | R-74 | RGSTR-74 | RGSS316R-74 |