The Latest At Valley Forge
Valley Forge is proud to announce that we have partnered with Curtiss-Wright to bring our industry-leading load indicating fastener technology to the nuclear and general power generation industries.
It is our passion to see the evolution of the bolted joint where the accurate assembly and our continuous load monitoring capabilities reduce the potential for premature wear, expensive downtime, and catastrophic joint failure. We believe that this new and exciting partnership will help to do just that.
The partnership will take our patented load verifying technologies and pair them with the bolting and sealing solutions offered by Nova and AP Services. We believe this combination will be a powerful force in the nuclear and fossil power generation industries.
As a service brand of Curtiss-Wright, Nova and AP Services have been supplying ASME Code, safety-related and quality critical fasteners, precision-machined components and fluid sealing solutions to the nuclear and fossil power generation, Department of Energy, Nuclear Navy and petro-chemical industries for over 30 years. The Nova/AP Services team has been energized by the addition of the Valley Forge product line and the expectation they will be solving problems in our customers’ most demanding applications.
For more information or discuss what this means for your bolting application, please reach out to our sales team anytime at email@example.com.
To learn more about Curtiss-Wright please visit their website at curtisswright.com.
Valley Forge & Bolt Manufacturing Co. in Phoenix has been producing high-quality hot forged industrial fasteners for over 40 years. The manufacturer — which also has heat-treating, threading, and machining capabilities — is well known for its novel (and patented) MaxBolt load-indicating fasteners. Each MaxBolt™ fastener features a tiny, built-in gauge that continuously measures and indicates the level of tension being exerted on the bolt.
Maxbolt fasteners are manufactured by inserting highly accurate and durable load-monitoring devices into high quality bolts and studs. Accurate assembly and continuous monitoring during production reduce the potential for premature wear, expensive downtime, and catastrophic joint failure.
According to Valley Forge & Bolt, load-indicating fasteners are compatible with conventional tightening and tensioning equipment and eliminate the need for ultrasonic, strain gages, and torque measuring devices. The system offers a simple and reliable method for accurate joint assembly, and helps to maintain the integrity of the bolted joint.
MaxBolt fasteners appear simple, but are critical for the types of projects carried out by Valley Forge’s customers, including fabricating and maintaining sub-sea platforms, mining equipment, and assemblies and fabrications used in nuclear laboratories, oil-and-gas processing, construction cranes, and power plants.
In order to operate at the level of reliability and efficiency required for these high-stakes jobs, Valley Forge & Bolt also needs precision and reliability in its manufacturing operation, which is centered on a dozen or so hot-forging machines, mainly mechanical upset presses and punch presses.
Some time ago, Ron Clarke, Valley Forge & Bolt president contacted Sutherland Presses to discuss a new approach to the process of making extra-long bolts. The project continued and evolved into a multi-year collaboration, reviewing existing processes, and developing new targets for safer production and higher output.
At an early stage of the collaboration it became clear to Clarke that Valley Forge & Bolt had an area of opportunity particularly suited to the strengths of Sutherland Presses. “The conventional forge presses we had were not ideal for long bolt heading,” he recalled. “They forced us to have more moving and rotating parts in our dies in order to load and extract the long bolts.
“When we met with the team from Sutherland, they came to the table with a fresh idea for a Front-Loading Sliding Table (FLST) Forge Press.” Since it was installed in 2013, the 600-ton vertical press at Valley Forge has become “a signature innovation,” according to Sutherland Presses. The California-based press builder has previously implemented the FLST design for manufacturers producing extra-long bolts for fasteners supplied to aerospace programs.
Valley Forge & Bolt’s Sutherland hot-forge press has been in service for several years now, successfully forging extra-long bolts.
“Due to the front-loading design, the press can be operated manually or automated,” Clarke explained about the machine’s advantages. “There’s less heat loss due to the faster heater-to-forge cycle which creates better material flow, and the precise, close-tolerance slide guide structure has improved die life.”
The extra-long bolts being produced by the FLST press go on to secure some of the most vital connections needed to build heavy industrial equipment. And, those applications are possible because of the precision design and performance, as well as the partnership formed between two industrial innovators.
Valley Forge is very proud to announce that our Load Indicating Fasteners have passed Military Shock Testing Standard MIL-S-901D!!
This is a rigid test that means great things for our fasteners moving forward with many different applications involving any degree of shock to the fastener while in service.
Shock Tests, Requirements for High-Impact Shipboard Machinery, Equipment and Systems
- Specification: Testing was completed per MIL-S-901D, Lightweight, Grade B, Class 1, Type C shock testing requirements.
- Location: Testing was done by Element Material Technology in Jupiter, Florida
- Purpose: The purpose of this testing is to verify the ability of shipboard equipment to withstand shock loadings which may be incurred during wartime service due to the effects of nuclear or conventional weapons.
- Load Indicating products tested:
- Standard SPC4™
- No-Standoff SPC4™
- Single Lever Maxbolt™
- Dual Lever Maxbolt™
- Mini Maxbolt™
- No-Standoff Maxbolt™
- MIL-S-901D is a common requirement for shipbuilders and other companies supporting the US Navy.
Our Maxbolt™ crosstalk video demonstrates the interactions which occur between fasteners in a typical flanged piping connection. This scenario is a perfect example of the complexity of many real-life bolted joints; particularly those with gaskets.
The demonstration clearly shows the limitations inherent with torque-tightening. The resulting differences between theory and reality can be significant. Not only does torque-tightening deliver limited accuracy in terms of resulting bolt tension, but it cannot tell you what happens once the torque wrench is removed.
All conventional tightening methods except for load indicating fasteners have this limitation, in that they are only useful for initial installation, and cannot be used to provide feedback from the bolts (and the joint) after tightening. It is true that methods such as torque-tightening, hydraulic tensioning, or turn of the nut techniques can be used in various ways after the initial bolt tightening in an effort to compensate for interactions such as bolt cross-talk. However these methods all fundamentally use the same approach; repeat the same (or a variant of the) procedure used during initial tightening. In the context of torque-tightening, a common practice in industry is to repeatedly torque the bolts in a joint over-and-over until the nuts do not turn. If the nuts turn this implies that the bolt became loose during prior tightening. Obviously this information is very subjective in nature and does not provide any useful information other than some form of load relaxation or joint interaction is actually taking place.
If load-indicating bolts are utilized, as in this video demonstration, the nature and magnitude of the interactions can be quantified, and more importantly corrected for. Rather than embarking on the time-consuming process of blindly re-torquing all bolts multiple times, a more calculated approach can then be taken which targets only those bolts with unacceptably low load.
Fastener Crosstalk is the phenomenon where as fasteners are tensioned, they affect the load on other fasteners around them, essentially speaking to each other.
We have been wanting to make a video that can show this intriguing display for a very long time. Because the Maxbolt™ can measure continuous tension in the fastener, there is simply nothing that can show crosstalk in fasteners better.
In making this video, an actual installation was done on an ASME class 300 flange unit. All measurements were recorded precisely during tightening with 3/4″ Maxbolt fasteners and a spiral wound gasket installed. The full procedure was: (1-5-3-7), (2-6-4-8) PCC- Legacy Modified.
First Pass: Fasteners were torqued to 55 ft lbs, which targeted 22% on the Maxbolt (40% of target torque STAR)
Second Pass: Fasteners were torqued to 138 ft lbs, which targeted 50% on the Maxbolt (100% of target torque STAR)
Third and Final Pass: Fasteners were torqued to 138 ft lbs, which targeted 50% on the Maxbolt (100% of target torque CW)
Calculated with K= 0.17, 100% on MB = 26,700 Lbf
During the first pass, there was a considerable amount of crosstalk in the bolts. A the very beginning all fasteners started hand tightened, but we found many were much more loose than this as we tried to torque them. During the second and final pass though, we really see the bolts crosstalking to each other and it reflected in their tension in the video. This video animation of an actual installation illustrates that controlling a joint with torque results in uneven tensioning of the fastener because of fastener crosstalk. With Maxbolts, designed preloads can be monitored continuously and show +/- 5% of targeted load to ASTM F2482 standards.
We hope you enjoy this video as much as we enjoyed making it. Please share and stay tuned for more animations like these to see more of the Fastener Revolution.
by Rusty Flocken, Mechanical Engineer
Valley Forge has recently developed a liner bolt innovation to improve the reliability of mill liners and liner bolts in ore grinding mill applications. Recently, concern has been raised about liner breakages triggered by stress concentrations found at the base of the liner pocket where contact is typically made with the bolt head. Liner bolt customers have also reported problems of ‘racing’ due to leakage of slurry between liner pocket and bolt head. This phenomenon can cause wear and premature failure to bolts and the mill shell alike.
The Sealing Mill™ Ridgeback® liner bolt has been designed and evaluated to prevent problems related to load distribution, as well as slurry leakage, which can lead to ‘racing’. The Sealing Mill™ Ridgeback® produces effective sealing of the bolt to liner pocket throughout the full range of bolt capacity, including very low loading conditions. Additionally, the polymer bushing is designed to transfer a pre-determined amount of bolt load while remaining load is distributed higher up on the head.
The polymer bushing was selected with a durometer rating based on results from testing. In order to achieve the best balance of load distribution and part life, factors such as memory retention, compliance and load bearing capacity were all considered.
The sealing mill liner bolt is currently available.