CNC Machinery Online Information

The oil drilling boom has proven to be an excellent match for thermally-applied coatings and machining processes that are the specialty of Watson Grinding & Manufacturing (Houston). The 47-year-old company has built its reputation by offering turnkey manufacturing of oilfield components such as valves, pumps, and compressor parts.

The company has developed a variety of thermally-applied coating processes to solve erosion and corrosion problems plaguing industrial valves used in today’s petrochemical, oil production, and manufacturing plants.

During the early 1980s, Watson was heavily involved in the development of high-velocity oxygen fuel (HVOF) coatings, which later became known as “Jet Kote.” In addition to HVOF coatings, Watson offers high-energy plasma, metallizing, and weld-overlay coatings.

For industrial valves, the type of spray coating chosen depends on the application. For example, HVOF coatings are applied at supersonic velocities to critical valve components where wear and erosion are serious problems. Tungsten carbide, cobalt, nickel, and chrome matrixes and chrome carbide coatings are all applied with this process.

Other coatings, such as chrome oxide, aluminum oxide, titanium dioxide, and zirconium oxide are used where dielectrics, thermal barriers, and corrosion resistance are required.

What makes Watson Grinding & Mfg. unique is its ability to machine, spray coat, and then finish valve components (by grinding, lapping, or honing) all at one facility. This allows the company to turn parts around quickly and reliably at competitive prices.

Valve components are made from raw material or rebuilt from existing parts. Watson Grinding repairs most ball-valve components, including chrome and nickel-plated parts. With today’s machine tools, the company can hold tighter tolerances and apply the coatings best suited to a particular job.

The company has added the role of OEM to its corporate profile. In recent years, it has begun manufacturing ball valves of the company’s own design, and has established a separate entity, Watson Valve Service, to manufacture this line of severe-service ball valves.

Customer demand was a major influence in Watson’s decision to become an OEM. When Watson determined that the design of its new valve line should be customer-driven, management interviewed a large cross section of its customers. The list included 116 companies in the petrochemical, refining, mining, pulp and paper, and power industries.

The responses were unanimous-customers wanted a valve that could stand up to their absolute worst applications. This meant a valve that could handle abrasive and corrosive environments, harsh chemicals, and extremes of temperature, pressure, and stress.

Armed with a wealth of customer suggestions and a blank sheet of paper, Watson Valve Service designed a severe service valve that is, in their words, a real “Texas Bad Boy.” The new valve was introduced to industry about five years ago, and Watson Valve Service now rivals its parent company, Watson Grinding & Mfg., in total sales. If pending contracts come in, it will easily surpass it.

Gearing up to serve this market niche required a significant investment in capital equipment and manpower. The company sought vendors that had a reputation for quality and were prepared to act quickly.

For CNC turning machines, the company selected Romi Machine Tools Ltd (Erlanger, KY). Currently Watson has six machines:

* A G260 for higher-volume smaller work up to 17” swing × 19” turning length (432 × 483 mm).

* A G50HT for larger production work with 26” swing × 51” turning length (660 × 1295 mm).

* Two M27 × 80” combination lathes for valve and shaft turning up to 27” swing × 80” in length (686 × 2032 mm).

* Two M27 × 120” (305-mm) combination lathes for longer shafts.

Watson Grinding was able to convert its valve turning operations to CNC in short order, and was shipping finished valves in a couple of weeks. Large-diameter parts are machined on the Romi M-Series lathes. The headstock has both a high and low-gear range, and these lathes feature rigid construction, large swing capacity, and the ability to machine tough materials. This dual-range gearbox allows the spindle motor to deliver high torque at low speeds, permitting heavier metal removal without bogging down the machine. The result is faster cycle times on large-diameter, high-alloy components.

Higher-volume jobs are put on the G-Series slant-bed machines. With 50-hp (37-kW) spindles, these machines are also equipped for heavy-duty turning. The machines are equipped with GE Fanuc 2 Ii controls and programmable tailstocks. A two-speed gearbox is standard on the G50HT.

Omer Cloutier, operations manager, explains: “Previously, making a large pump shaft on our manual lathes would take 20 hr. Now the shaft takes 11 hr on the Romi M27 due to the ability to program all the profiles on the shafts with a single tool. The need for a programmer is eliminated, because the machinist programs the part as he goes.”

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