API Spec 16A clamps differ from all other API equipment in regard to design and hydrotest. Clamps serve as fasteners similar to bolts, they do not come in contact with well fluid, and they may connect several API specified connectors having different nominal sizes and working pressures.
API Spec 16A permits clamps to have marking as to clamp number, e.g. No. 6, or a specific connection, e.g. 3-1/16” 15M.
API Spec 16A, 3rd Edition, states that: “Each clamp shall be designed for the highest loading that may be induced by any hub it is intended to fit.” WOODCO USA interprets this to mean any API 16A specified hub a clamp will fit. We also understand this to mean that any and all clamps shall experience a test to this highest design loading regardless of the manufacturers or users choice in marking.
The table below identifies the API Spec 16A clamps by number designation and identifies the hub(s) each numbered clamp will fit. The table further provides the maximum load applied to the clamp at test pressure related to each specified hub, with the hub which applies the greatest load to the clamp at test pressure highlighted and indicated in bold type.
| Clamp No. | Hub Nominal Bore | Hub Working Pressure (WP) psi | Hub Ring Gasket (RX) | Hub Ring Gasket (BX) | Max Load (Lbs.) Applied to Clamp at Test Pressure (1.5 X WP) |
|---|---|---|---|---|---|
| 1 * | 1 13/16 | 10,000 | 151 | 131,086 | |
| 2 1/16 | 5,000 | 152 | 86,999 | ||
| 2 * | 1 13/16 | 15,000 | 151 | 190,086 | |
| 2 1/16 | 10,000 | 152 | 159,195 | ||
| 2 9/16 | 5,000 | 153 | 120,230 | ||
| 3 * | 1 13/16 | 20,000 | 151 | 249,084 | |
| 2 1/16 | 15,000 | 152 | 231,390 | ||
| 2 1/16 | 20,000 | 152 | 303,586 | ||
| 2 9/16 | 15,000 | 153 | 324,090 | ||
| 4 * | 2 9/16 | 10,000 | 153 | 222,160 | |
| 3 1/8 | 5,000 | 154 | 157,577 | ||
| 5 * | 3 1/16 | 10,000 | 154 | 293,446 | |
| 4 1/16 | 5,000 | 155 | 244,770 | ||
| 6 * | 2 9/16 | 20,000 | 153 | 426,020 | |
| 3 1/16 | 15,000 | 154 | 429,315 | ||
| 4 1/16 | 10,000 | 155 | 460,951 | ||
| 7 | 5-1/8 | 10,000 | 169 | 621,164 | |
| 8 | 3 1/16 | 20,000 | 154 | 565,183 | |
| 4 1/16 | 15,000 | 155 | 677,133 | ||
| 5-1/8 | 15,000 | 169 | 917,346 | ||
| 7 1/16 | 5,000 | 156 | 600,140 | ||
| 9 | 5,000 | 157 | 901,744 | ||
| 9 * | 11 | 3,000 | 53 | – | 690,839 |
| 10 * | 4 1/16 | 20,000 | 155 | 893,314 | |
| 7 1/16 | 10,000 | 156 | 1,151,311 | ||
| 9 | 10,000 | 157 | 1,714,299 | ||
| 11 | 5,000 | 158 | 1,270,351 | ||
| 11 * | 13 5/8 | 3,000 | 57 | – | 924,974 |
| 12 * | 16 3/4 | 2,000 | 65 | – | 919,579 |
| 13 * | 13 5/8 | 5,000 | 160 | 1,599,602 | |
| 14 * | 16 3/4 | 3,000 | 65 | – | 1,360,313 |
| 15 * | 7 1/16 | 20,000 | 156 | 2,253,657 | |
| 11 | 15,000 | 158 | 3,659,760 | ||
| 13 5/8 | 10,000 | 159 | 3,588,470 | ||
| 16 * | 21 1/4 | 2,000 | 73 | 1,409,609 | |
| 17 * | 20 3/4 | 3,000 | 73 | 2,087,840 | |
| 18 * | 21 1/4 | 2,000 | 73 | 1,409,609 | |
| 19 * | 16 3/4 | 5,000 | 162 | 2,145,269 | |
| 20 | 30** | 1,000 | SPCL | 1,327,524 | |
| 22 | 7 1/16 | 15,000 | 156 | 1,702,490 | |
| 11 | 10,000 | 158 | 2,465,061 | ||
| 25 | 7 1/16 | 2,000 | 45 | 235,318 | |
| 26 | 18 3/4 | 15,000 | 164 | 9,406,187 | |
| 21 1/4 | 10,000 | 166 | 7,893,053 | ||
| 27 | 18 3/4 | 10,000 | 164 | 6,300,799 | |
| 21 1/4 | 5,000 | 165 | 3,800,556 | ||
| 28 | 11 | 20,000 | 158 | 4,854,467 | |
| 13 5/8 | 15,000 | 159 | 5,336,027 | ||
| 16 3/4 | 10,000 | 162 | 4,261,948 |
** We have also included a WOODCO USA proprietary 30″ 1000 special hub and No. 20 clamp for diverters.
