Tooling Partner Helps Pump Things Up
Faced with a need for increased productivity, a major manufacturer of oil & gas equipment turned to an innovator who could help move the metal.
David L. Cope
Manager, Technical Programs,
Engineered Solutions Americas
Higher gasoline prices. Dependence on foreign oil. Emerging alternative energy sources. Increasing environmental concerns. Electric vehicles, hybrids, and natural-gas-powered buses.
The energy landscape is white hot with manufacturing and research activity. If there is a common denominator for those participating in oil drilling, shale gas extraction, wind farms, or numerous other energy businesses, it’s that those who are quick-to-market make money while the slow get a lot of missed opportunities.
Making it its business to be among the agile, a global manufacturer of industrial compressors, blowers, pumps, loading arms, and fuel systems, reached out to its technology partners for assistance. Its long-established operating philosophy says that how results are achieved is as important as what is achieved. Additional tenets include showing initiative and a bias for urgency; while using rigorous logic and methods to analyze difficult problems and implement effective solutions. Not stopping at the first answers is key.
Finding itself with an immediate need to increase productivity, the pump manufacturer found a partner with many of the same beliefs in Kennametal Inc. Unprecedented growth in natural gas exploration led to increased demand for the fluid-end manifolds the company manufactures. Despite the plant’s significant increase in head count, demand for manifolds had increased tenfold.
As the company and Kennametal had a business relationship, plant management immediately sought to work with Kennametal to adopt an “any and all solutions” mindset to boosting output both at its own plant and among the many subcontractors it was using to keep up with demand.
Deep Radii, Thousands of Pounds of Chips
Fluid end manifolds are critical to oil and gas drilling operations and endure extreme amounts of wear. They are assemblies for heavy-duty, high-pressure pumps that receive fluid from a supply manifold and direct or transfer the fluid to an outlet manifold.
The manifold base can be a forging of modified 4140, 4150 or 17-4 steel grades anywhere between 8000 and 16,000 lb (3629 to 7257 kg). As these can be around 2000 lb (907 kg) when finished, the first challenge was to come up with milling tools to remove as much metal as possible as quickly as possible in a tough-to-machine material. Design features included very deep radii of 6" (152.4-mm) deep on the mounting side and other numerous external and internal features.
Kennametal’s first response was to design custom T-slot cutters that it supplied for testing on the customer’s equipment. The first test met with limited success, but with customer input, we made adjustments and the second test was very successful. Based on this initial success, the company and Kennametal committed to a team approach to explore the most effective mix of custom and state-of-the-art standard tools to achieve the needed productivity gains.
With the vast amount of material to be removed both on the surface and internally, it eventually became a two-pronged milling and holemaking approach to tool development. The results were a combination of applying the most effective standard tools and developing a number of custom solutions across multiple Kennametal milling platforms, including custom Harvi T-slot cutters, custom Harvi helical cutters, and other indexable face and copy-milling solutions. On the holemaking side, KSEM Plus indexable drilling, KenFEED plunge milling, and deep-hole (10×D) solutions were engineered to attack the required internal features.
Holemaking is a particular challenge with pump manifolds. Kennametal’s KSEM Plus modular drills combine the high feed rates and length/diameter capabilities KSEM modular drills are known for with the high-speed and low consumable costs of indexable drills.
The benefits are increased metal-removal rates and productivity in many applications. KSEM Plus tools, suitable for holemaking in steel, stainless steel, cast iron, and nonferrous alloy workpieces, consist of a steel body coupled to a high-strength steel head. A single tool body can handle a range of drillhead sizes. The drill body features a central coolant hole that maintains body rigidity while allowing maximum coolant flow through the tool. A margin and relieved clearance eliminate trapping of chips between the drill body and hole wall to increase tool body life and improve hole surface finish, while differential helix flutes smooth chip evacuation and maintain rigidity.
KSEM Plus drill bodies accept a range of head diameters, (2.79–5" [71–127 mm]), and users can easily replace inserts or heads without removing the body from the spindle, further improving holemaking efficiency. At the spindle, standard WN/WD or SSF shanks provide maximum toolholding security, stiffness, and accuracy with flanged face contact. The flexible shank configuration allows use on machining centers and in lathes with an inexpensive coupling system.
Mating the body and head is the proprietary Flexible Drilling System (FDS) coupling system, which uses radially activated locking screws to guarantee high repeatability and minimal runout. KSEM Plus modular drills with B1 and B2 heads also incorporate wear pads that add stability in cut and provide support when machining intersecting holes. Assembly and tool change are fast and easy, and the FDS allows one head to fit several body length/diameter ratios.
KSEM Plus modular drills are available in standard lengths of 3, 5, 8, and 10× diameter in metric and inch sizes. Custom tools with HSK, KM, FCM, or ISO tapers; length to 17× diameter; and intermediate diameters are also available.
One customer had a spool part used for undersea drilling made of annealed 4130 medium- to high-alloy steel, run on the company’s 40-hp (30-kW) CNC horizontal boring mill. The spool part had a flange on each end, requiring 24 through holes on one end, indexing the part, and 20 holes on the other.
The holes were straightforward mounting holes without threads or a high finish tolerance, so the customer used a straightforward holemaking method, a coated 2.375" (60-mm) diameter spade drill. With a single cutting edge, they had to run the spade drill in pecking cycles, starting the hole and then withdrawing the drill, usually used to break chips so they are small enough to flow up through the flutes on the tool without causing damage to the hole surface or the drill.
For example, a variable peck cycle could start with a 1" (25.4-mm) peck, then the tool would be retracted slightly to break the chips. The next peck would only go 0.5" (12.7-mm) deeper, followed by one 0.25" (6.3-mm) deeper, with the last peck going only 0.05" (1.3-mm) deeper than the previous peck. The deeper the drill goes, the more difficult it is for coolant to get to it, so pecks are used both to evacuate chips and get more coolant to the tool tip. And because they take so much time, pecking cycles are usually considered a “last resort” holemaking strategy.
As this part required both lathe work and mill work, a complete job was taking in the area of 185 to 200 hours. The KSEM test Kennametal was able to run for the company had a baseline of over eight and a half hours (512 minutes) just for making 24 holes using the spade drill, and there were still 20 holes on the other end of the part to drill. Making 24 holes with the KSEM Plus drill took 38.4 minutes.
Often, direct input from the customer’s team spurs Kennametal’s effort at effective tool development. The pump manufacturer’s plant was a relatively mature operation with a lot of experience in leaning out its processes. With years of experience and acquired knowledge, it was hard for them to believe that significant improvements were possible. In this case, plant management deserved credit for fostering a collaborative environment focused on accelerating the productivity curve.
While this relationship remains ongoing with many tooling development projects currently underway, initial results have been outstanding. From 110 machining hours per manifold, current performance stands at less than 40, a reduction in machining time of approximately 64%. Moreover, the same tooling concepts can be leveraged at multiple OEM and subcontractor sites to drive the significant growth goals for this customer to dominate this industry segment.
Such collaboration stands out as an example of mutual success between customer and technology supplier, particularly when many companies facing such significant growth opportunities immediately think of expanding capital equipment first and consider how to choose the most effective tooling solutions later. Having a tooling partner involved early in the process can save significant time and money. Collaborative engineering can save hundreds of thousands of dollars by right-sizing capital investments and ensuring that new machine tools provide the necessary spindle connections, torque, rigidity, and horsepower to drive the newest tooling innovations.
Faced with a white-hot energy industry, this kind of success demonstrates what can happen when a driven customer and motivated technology partner commit to test, adjust, and document continued process solutions. The result is a plant newly positioned for increased productivity and future growth.
This article is a digital exclusive feature for the 2013 edition of the Energy Manufacturing Yearbook. Click here for PDF.