Tucker Valve Seat Company Overview
Balancing Mass Production with Customized Products
Valve Seats to Order - Quickly and with Extreme Quality Control
By Ellen Hopkins of Compressor Tech Two Magazine
"Its a matter of mass production versus catering to the customized needs of aftermarket clientele," said Philip Carrasco, President of Tucker Valve Seats of Odessa, Texas, U.S.A., which maintains a large semi-furnished inventory of industrial engine valves seats in anticipation of customer needs. Those customers, he said, include some of the world's largest industrial engine rebuilders and a large percentage of their needs involve customized products. Nearly 35% of Tucker's manufacturing work includes custom fabrication.
"There are no manufacturers left in the U.S. "manufacturing" valve seats on a day-to-day basis for all industries in addition to providing customized manufacturing, which we often turn around in a day," Carrasco said. "Our inventory cover 100% of sizes for valve seat inserts needed in all industries. You name it and we cover it. When a large bore engine goes down, we have to be ready to quickly supply whatever valve seats [the] rebuilder requests.
He said Tucker can produce on large industrial seat every 24 seconds; automotive valve seats are manufactured one every 11 seconds.
"When a customer calls and has completed his tear-down of a specific engine and cylinder head, the customer determines if the cylinder head pocket replacement will need specific machining or can be filled with a standard insert," Carrasco said. "It might be an oddball size that doesn't need machining but will have to be custom manufactured. At that time, we often receive a customer request to begin stocking this oddball size in our inventory just for him. This is what separates us from other companies in the valve seat industry. We can make that special size, we can fit those needs and we can do it rapidly."
He said that the company stocks $1,000,000 + in perpetual inventory.
Carrasco said there are some engines that are hard on valve seats and may require alloys of up to 40% cobalt. The addition of cobalt nickel is common for marine environments. Also, water-cooled applications often require stainless steel. The company uses a variety of alloys to meet customer needs.
In 1957, when Thomas Tucker founded the company, steel alloy valve seats were universally used. Once the hotter-burning unleaded fuels came into play, along with the move toward anti-pollution engines for automotive and industrial use, the use of specialized insert alloys became important.
Today, Tucker employs over 40 people including those at numerous distribution centers and salesmen through the United States, Canada, Mexico and Australia.
Carrasco said the predominant Tucker material has been an iron-based alloy to which chrome and molybdenum are added for strength. While those elements are common in many valve seats, what separates Tucker from the rest of the industry is the addition of vanadium and tungsten. He explained that these two elements combine to form tight carbide structures at elevated temperatures and that the alloy gives valve seat inserts greater wear resistance and excellent heat transfer along with the ability to operate in temperatures in excess of 1400*F (760*C).
He said that many people visualize valve seats as being sliced one after another from bar stock. In actuality, he said, all Tucker valve seat inserts are poured as individual castings.
Inserts go through three stages in Tucker's manufacturing facility: production, grinding and inspection. The production department takes the raw casting from inventory and proceeds to bore, face and angle the insert to customer specifications. It then goes to a cut-down department where the insert is is cut to the required depth on CNC lathes and double-disk grinders. Knowing the concentricity of the valve seat pocket for each intended replacement insert is vital to press fit. Carrasco said the customer determines how much damage was done to the counter bore and whether it is still usable or in need of machining.
"This is the type of data we ask for so we can provide the insert a customer needs," Carrasco said, "If a rebuilder has a couple of oddball sizes, we begin with semi-finished goods and then use smaller piston grinders that allow us to machine the unusual sizes. We often complete the work within two or three hours of receiving the order. These don't need to go through our regular production line: they go through a customized line."
High quantity or special order, Carrasco said the inspection process for every manufactured valve seat is the same. "From the time the raw casting enters the production department, the valve seat is repeatedly inspected at various stages to ensure quality," he said. "We know we don't have to maintain this level of continual inspection, but it has been in our system. It maintains quality control and we see no reason to change."
Certain customers have certified Tucker to manufacture valve seats used in backup generators for nuclear waste projects. This certification requires 100% traceability, which means that the manufacture of any particular valve seat can be traced back to the day it was poured and the specs by which it was ordered. Carrasco said Tucker is capable of tracing that same information for every customer.
The Tucker manufacturing facility is equipped with a filtration system to treat all solvents used in manufacturing process. There is also a 67,500 sq.ft. inventory warehouse on site.
The business was founded in 1957 by Thomas M. Tucker with his father, who had worked in engine parts but not specifically in valve seats. One of Tucker's initial customers was Phillips Petroleum, a large major oil company and producer in the Permian basin's natural gas fields. The first valve seats were for some of Phillip's compressors in a Leroy engine. Through his work in the oilfield, Tucker realized the need for specialized valve seat inserts and decided to start the company.
Carrasco said that until about 10 years ago Tucker's customers were primarily automotive. a workload that used to consist of 70% automotive and 30% other industries is now just the opposite due to an influx of foreign automotive parts entering the U.S. market. He said the company's large number of industrial customers and its ability to quickly respond to customized insert orders has kept it busy.
Tucker can supply valve seat inserts from its Odessa manufacturing plant to natural gas production areas worldwide. For example, because Australia does not have a valve seat manufacturer within its borders, Carrasco explained that Australians used to purchase universal types of valve seats elsewhere and machine them to complete cylinder head requests. Tucker representatives visited the country, determined what was needed, and then established specific size depths that Australian companies could order. Valve seats with outside diameters in metric and imperial sizes are stocked in six warehouses located throughout that country and an Australian distributor handles the orders.
Tucker also manufactures cast-iron welding rod as a separate service. Unlike aluminum cylinder heads, the temperature on cast-iron welding must be maintained throughout the welding process. Carrasco said the 24-hours of post-heat cooling is just as important as the pre-heat, so the weld doesn't separate or crack. In some cases temperature control must be maintained up to a 72-hour post-heat time to ensure a good weld. He said they offer this product because many customers want to handle their own welding. In the natural gas industry, cast-iron cylinder heads are being replaced by aluminum and now comprise 60% of the automotive market.
