Facility in Focus: Permalok® St. Louis Plant
>
Facility in Focus Series:
An Inside Look at Northwest Pipe’s Manufacturing Plants
With 13 facilities in the U.S. and Mexico, Northwest Pipe Company (NWP) plants are strategically located to support water infrastructure projects in communities across North America. Each facility offers a range of manufacturing capabilities and specialized services that provide engineered solutions for water transmission, wastewater, stormwater, and process system applications. Although geography and product specialty vary from plant to plant, our commitment to quality, service, and safety remains unwavering across locations. In our Facility in Focus series, we take a closer look at each of our plants, showcasing the unique manufacturing capabilities, technology, and skilled workforce that power the production of our innovative and durable water infrastructure products.
The St. Louis Plant
Permalok®, A Northwest Pipe Company | Trenchless Steel Casing Pipe
Northwest Pipe Company’s Permalok® plant is located in the Ferguson area of St. Louis, Missouri, just a 10-minute drive from the St. Louis Lambert International Airport. A hub for industry and commerce in the Midwest, the region boasts an advanced manufacturing sector that includes the likes of major automakers and aerospace engineers. Permalok® Corporation opened its doors in 1995, joining the ranks of these manufacturers and bringing to market a cutting-edge press-fit steel casing pipe product that has since grown into an industry-leading line of trenchless technologies.
In 2014, Northwest Pipe Company (NWP) acquired Permalok®, expanding its trenchless steel piping solutions to include Permalok’s range of patented press-fit joint systems. Today, the St. Louis plant’s central location at the crossroads of several major interstates allows NWP to support trenchless infrastructure projects across the U.S. and Canada.
Permalok® Steel Casing Pipe
The 11-acre St. Louis facility relies on a team of 27 talented individuals and is equipped with state-of-the-art machinery capable of producing the highest quality trenchless steel pipe on the market. What makes Permalok® unique is its patented press-fit interlocking joint system, which creates secure weld-free connections that install quicker than any competing pipe in the field. This equates to reduced field time and major cost savings for contractors and owners. Our Permalok® product is especially suited for trenchless installation in urban settings and can be installed under busy streets, railways, or bodies of water.
Manufacturing Process
Each piece of Permalok® is custom-engineered to the exacting specifications of a project and can be manufactured from either straight-seam or spiralweld steel pipe. Our St. Louis facility manufactures straight-seam Permalok® pipe on-site and fabricates joint ends for spiralweld steel pipe produced at other Northwest Pipe Company locations.
Straight-seam Rolled Process
The straight-seam pipe production process starts with a steel plate being cut to size on a plasma cutter. Each piece is rolled in a roll-bending machine, which utilizes the natural flexibility of steel to gradually round the plate into an open cylinder. The cylinder is then welded both internally and externally to form the pipe. Our St. Louis plant is capable of producing straight-seam pipe in diameters of 30- to 156-inches, in lengths up to 40 feet, with a wall thickness of up to 2.5-inches.
Patented Interlocking Joint Systems
The hallmark of Permalok® pipe is our patented press-fit interlocking joints. We currently offer seven proprietary joint designs, each optimized for specific trenchless installation techniques. Once the pipe barrels are produced, a precision-machined interface joint ring is welded onto each end of the pipe. Our certified welders take special care to ensure a quality weld that is flush with the interior and exterior surfaces of the pipe, which facilitates quick alignment and connection in the field. With a team of highly skilled fitter-welders, the majority of our St. Louis workforce is specially trained to support this essential function of the production process.
Protective Coatings and Linings
Each piece of Permalok® steel casing pipe is manufactured to the exacting specifications of a project. Our team can accommodate any coating or lining specified by our customers, ensuring long-lasting performance in applications where corrosion or exposure to the elements is a concern.
Committed to Quality
Permalok®, A Northwest Pipe Company, is committed to providing high-quality products to meet the needs of all our customers. We do so by maintaining our quality management systems to strict AWWA and ASTM standards, and our own industry-leading benchmarks. Our St. Louis plant has a rigorous quality manufacturing process that produces low burr welds of 1/8″ or less, resulting in a smooth, friction-free installation that is unmatched by our competitors. Before leaving the plant, each piece of pipe is thoroughly inspected for quality assurance.
Industry-Leading Innovation
The Permalok® team is constantly innovating to bring fresh ideas to the field of underground construction. We work closely with contractors to understand their challenges and create new solutions that minimize risk and increase productivity. For instance, we developed the Permalok® AB Joint, which is specifically designed for Auger Bore installations, based on the feedback we received from our customers. One of our team’s latest achievements is the Permalok® Radial Bending Joint (RBJ), which enables steel pipe to be installed along a curved radius in microtunneling applications—a first in the industry.
Project Support
At Permalok®, we offer project support through a dedicated point of contact, providing personalized assistance at every step of the way. Our commitment to project success starts with the efforts of our skilled production team in St. Louis and extends to installation support for the contractor in the field. While each project is unique, our objective is always to deliver unparalleled service, exceptional value, and the best quality product, all while meeting project milestones and staying within budget.
