You may install a WOODCO USA® BRAND clamp in any orientation desired. Prior to installation of the clamp, clean and lubricate the tapered contact surfaces of the hubs and the clamp with API RP 5A3 / ISO 13678 thread compound or other extreme pressure grease. Fluoropolymer coated bolts and nuts do not require lubrication.
Keep clamp halves matched and turned so that all marking appears on the same side of the clamp.
Install Fluoropolymer coated bolts, nuts and spherical load bearing washers, arranged as shown in the illustration below.
After all nuts have been run down by hand, start wrench tightening following the sequence of the numbers indicated (marking the number on the Clamp with a crayon aids in keeping track of the tightening process).
Because of the nature of the fit between Clamps and Hubs, a considerable number of nut turns may occur before achieving a significant percentage of recommended torque.
During all of the following steps, keep the gap between Clamp halves even on both sides, with nuts made up approximately the same amount on each end of the bolt.
- First time around just snug the nuts with a hand wrench.
- Continue tightening the nuts, closing the Clamp around the Hub evenly, until the space between the Hub neck and Clamp bore becomes nearly equal.
- Continue tightening to achieve approximately 25% recommended torque.
- Tighten another round to approximately 50% of recommended torque.
- Again to approximately 75% of recommended torque.
- Again to approximately 100% of recommended torque.
- Repeat this process until nuts do not move under 100% recommended torque.
- If possible, re-torque after 24 hours. Most of any bolt preload loss occurs within 24 hours after first tightening.
|Clamp Number||Bolt Size||Fluoropolymer Coated B7/L7 Bolts*|
|(Ft-Lbs)||N x M|
|1, 2, 25||7/8” – 9UNC||185||251|
|3, 4, 5||1” – 8UNC||280||380|
|6||1-1/8” – 8UN||400||542|
|7, 9, 11, 12||1-3/8” – 8UN||735||997|
|8||1-1/2” – 8UN||960||1,302|
|14, 16, 20||1-5/8” – 8UN||1,225||1,661|
|10||1-7/8” – 8UN||1,890||2,562|
|13, 17, 18, 22||2-1/4” – 8UN||3,270||4,434|
|15, 19||2-1/2” – 8UN||4,500||6,101|
|28||3” – 8UN*||7,780||10,548|
|27||3-1/4” – 8UN*||9,900||13,423|
|26||4” – 8UN*||18,475||25,049|
|*||WOODCO USA assembles API 16A Clamps with L7 Bolts only.|
|Torque values for Bolts over 2-1/2” apply to L7 Bolts only.|
Confirm make up on API Spec 16A hubs using RX and BX ring gaskets by observing, through the gaps, that the hub faces have come into contact.
Note: Older style hubs using RX ring gaskets will have stand-off between the hubs. This stand-off will equal the stand-off between API 6B flanges sealed with the same RX gasket. After make up, clearance between the hub neck O.D. and the clamp I.D. should appear uniform.
Excessive torque to achieve make up indicates some problem with fit or finish (rust on clamp or hub mating surfaces can result in difficulty during make up).
Protect the mating surfaces of hub connections and clamps in the same manner as ring grooves when not in use. Clamps or clamp hubs, if allowed to rust, lose their dimensional accuracy and finish and may become unusable.