Valley Forge & Bolt Mfg. Co.

The integrity of a bolted joint is jeopardized when fasteners lose their tension. This loss of clamping force begins during assembly due to elastic interactions and joint relaxation. Self-loosening continues when the joint is put in service due to vibrations, shock, temperature changes, embedment, etc. The SPC4™ joint allows the end-user to re-tighten only the bolts or studs that have lost their clamp load. This results in a tremendous saving of maintenance time, money and replacement parts. For a minimal investment, the SPC4™ offers maximum joint integrity with optimum performance.

With five different models to chose from, there really is a reader for every application. Featuring portable and pocket sized options with both analog and digital reading capabilities. Each reader displays bolt load (joint clamp load) as a percentage of its proof or yield load (customer choice). There are optional abilities to electronically control the installation tool to a pre-set clamp load, as well as data storage and upload for analysis capabilities. Visit the Instructional Videos page to learn more and watch videos on how each SPC4™ Reader works and operating instructions.

With the VF Two Piece Mill sealing System, the counter bore forms a pocket to contain the outer diameter of the neoprene sealing washer. The sealing washer is thicker than the counter bore depth, and protrudes out of the forged washer. This is by design and meant so that when squeezed, a seamless seal will form around the liner bolt threads and at the shell face giving a leak free, tight system, when properly installed. The neoprene washer is meant to squeeze until the forged washer outer ring becomes solid against the shell, at approximately 150 foot-pounds of torque.

When Grinding Mills age, the location in the shell for liner bolt nuts can become worn. This can cause slurry leakage. Slurry leakage is a real problem. It cuts through the shell and makes the leak grow and grow: a viscous cycle. By using our Pitbull™, this can mitigate any more damage from happening until there can be a complete repair of the hole created from a bolt boring around. Our Pitbull™ Liner Washer grips and holds like no other washer can. The Pitbull™ Liner Washer is one of our most popular washers because they hold like a “pitbull’s bite”, and provides that stable platform needed in worn areas. In addition, for bolt diameters of: 1 ¼”, 1 ½”, 2″ (M48 and M52), we even have an Oversized Pitbull™ made to cover a badly worn bolt hole area, on the shell. Our newest creation, in this respect, is a Double Sided Pitbull™ Liner Washer. This washer was developed because, often times, a liner bolt is not initially manufactured long enough to allow for both the Pitbull™ Liner Washer and the Two Piece Sealing System to fit. Then, when an enlarged shell hole occurs as the mill ages, and needs a Pitbull™, the liner bolt must be replaced with a new, longer bolt to accommodate both systems. Now there is another option. The Double Sided Pitbull™ is the solution to accommodate both systems without requiring an entirely new, longer bolt.

Now introducing Wireless Load Monitoring and Data Logging with the SPC4™ technology. Designed to your specific application, the wireless and data logging capabilities are tailored to your needs. Contact us today to receive a product specification sheet with all the possibilities for your application.

The Ridgeback™ Liner Bolt was designed by our engineers especially to solve bolting problems that users were encountering when liners were installed. With standard bolts, there is a 18″ all-around clearance between the bolt and the liner; therefore, when the bolt is installed, it rests on two points and is not stable. To stabilize the assembled joint, our engineers designed ridges along the taper section of the bolt to conform to the tapered surface of the liner hole when assembled. These ridges plastically deform during assembly to take the individual shape of the tapered liner seat and bolt seat, creating a solid surface to tighten against.