Lamons SPC4 Bolt Technology

Lamons is excited to announce our new licensing relationship and partnership with Valley Forge Manufacturing. Under this license, Lamons will be manufacturing the SPC4TM and Maxbolt technology in our Houston location. Considering Lamons exposure and service capabilities that we provide to the refining and petrochemical industries, this will result in an expanded market for this product and provide a new dimension to bolted joint technology.

The SPC4TM load indicating fastener technology allows users to install a bolted assembly with confidence. A user can monitor the clamp load of any SPC4TM bolted joint whether static or dynamic, by attaching an indicator datum disc located on the end of the fastener and reading the value using a mechanical indicator. This indicator is calibrated to detect the differential space between the indicating pin and datum head. The differential space is translated into a gauge reading that precisely indicates the fastener’s loading, related to ultimate yield strength.

The integrity of a bolted joint is jeopardized when fasteners lose their tension. This loss of clamping force begins even during assembly due to elastic interactions and joint relaxation. Self-loosening continues when the joint is put in service due to vibrations, temperature changes, shock, etc. The SPC4TM joint allows the end-user to retighten only the bolts or studs that have lost their clamp load, resulting in a tremendous saving of maintenance time, money, and replacement parts.

For a minimal investment, the SPC4TM offers maximum joint integrity with optimum performance. The ability to monitor stud load after it has been installed is a key feature and something very unique to this SPC4TM technology.

A fastener is modified by machining a small hole into the head. Minimal modifications to the bolt assures basic bolt design integrity. A gage pin is inserted into the hole and secured at the bottom. A datum disk is fitted on the top of the bolt head and forms a flat surface with the top of the gauge pin when the bolt is unloaded. When the bolt is tightened, it elongates and the gauge pin is drawn into the bolt away from the datum disk surface.

The benefits of this concept allows the fastener to be loaded many times as long as the stress remains in the elastic range, meeting the criteria of ASTM F2482. An accurate assessment of loading can also be obtained after the joint has been put in service.

SPC4 Installation Videos

These videos illustrate an SPC4 installation on a chemical facility reactor. In this case, the flanges are titanium and extremely sensitive to elevated load which has the potential to plastically yield the flanges. The flanges must be held to a target of 11% fastener stress. By utilizing and monitoring the elongation of the fasteners, the operators can easily achieve the desired load without the inconsistencies associated with torque and friction. For the first time in the history of this unit, it is operating at maximum efficiency and producing more product that ever anticipated due to accurate preload and subsequent monitoring with SPC4.