Figure 1 The first pilot-operated steam pressure regulator patented by Paulsen Spence in 1926.
In an era of automated control systems and process technologies, engineers and designers tend to overlook the simpler, cost-effective systems in favor of expensive, complicated, installation and maintenance intensive products. There are HVAC and process applications where automated control, like the type provided by a pneumatic or electrically actuated control valve, are preferred. However, in many situations, the pilot-operated steam regulator is the low-cost, low maintenance alternative to these expensive control systems.
Pressure reducing valves of the 1920s provided acceptable performance but lacked accuracy and speed. Additionally, these valves tended to seize up or require a great deal of maintenance during normal service life. Lack of performance and the frequency of maintenance calls helped drive demand for a better performing regulator and, in 1925, inspired Paulsen Spence to design the first normally closed, pilot-operated, diaphragm actuated pressure regulator, the Spence Type ED (see Figure 1).
The Spence pilot-operated pressure regulator revolutionized the way energy producers supplied low-pressure steam to their customers by providing greatly improved accuracy in pressure control. This feature, as well as dependability and low maintenance, soon made pilot-operated regulators the standard method of pressure reducing and control throughout the steam industry. This method of steam reduction and distribution is still one of the most accurate methods of HVAC and process control available today.
Paulsen Spence started his career as a manufacturer's representative, selling pressure-reducing valves in the New York City area. In 1926, shortly after filing a patent application for his design, Mr. Spence and his business associates met with Leon Dexter, owner and operator of the Rider-Ericsson Engine Company of Walden, NY, who agreed to share his production facility with the new entrepreneurs. The Rider-Ericcson Company was founded in the 1870's by Captain John Ericsson, inventor of the hot air engine, the screw propeller and, most notably, the famous U.S. Navy ironclad ship, the USS Monitor (see Figure 2).
Figure 2 USS Monitor, The first US Navy Ironclad ship (1862)
Orders for Spence products grew steadily. Throughout the late 1920s and mid 1930s, the company's product offering had expanded to include a full line of pilot-operated and direct-acting regulators for pressure, temperature and backpressure control, desuperheaters and strainers. By 1939, Spence regulator sales surpassed the sales of the Rider-Ericsson products and Paulsen Spence purchased the plant and manufacturing equipment from Leon Dexter. During this period, Spence regulators were being used extensively in manufacturing facilities throughout the United States. Demand for these products was so great that, during the Second World War, the U.S. Government limited the sales of our steam pressure reducing valves to the government and their sub-contractors only because Spence regulators were vital to the production of essential war materials. In recognition of the company's contribution to the nation's war efforts, the Spence Engineering Company received the coveted Army-Navy "E" Award for production efficiency.
Among Paulsen Spence's many inventions (over 60 patents) were: the Type ED packless main valve with external pressure pilot, Type T14 temperature sensing pilot, Types T124 and T134 combination pressure and temperature control pilots, Type Q back pressure pilot, Type N differential pressure pilot, Types P and Type F46 pump pressure pilots and various pneumatic pilots. Spence's pilot-operated pressure and temperature regulators were the blueprints for many of the externally pilot-operated regulators manufactured and sold in the world today. Although there have been some changes to the materials and configuration of his inventions, the overall design and operating principals have remained the same since their inception 80 years ago.
By the early 1960s, Spence Engineering Company owned half of the market for pilot-operated steam regulators. In 1967, the company moved to its current 79,000 square foot location in Walden, NY. In 1984, the Spence family sold the company to Watts Industries, a well-established valve manufacturing corporation with a strong presence in the HVAC market. From 1984 through 1994, fueled by a reputation for building quality products, Spence sales more than doubled from $6.7 million to $14 million. Over the next 12 years, Spence Engineering Company introduced several innovative, cost-saving products to the HVAC and industrial process markets. These products include: Type "J" Series Pneumatic Control Valve (1986), "Nova" NFT Series Variable Orifice Steam Traps - the first "Made In The USA" free float steam trap (1992), CDH Series patented thermostatic sanitary steam trap (2001) and the "CoMBo" CME Series - the industry's first condensate measuring elbow thermostatic steam trap (2006).
Spence Engineering has broadened its product offering, of fluid control and steam specialty devices, and improved its manufacturing capabilities by making the following improvements and acquisitions:
- 1989 Spence acquires the Nicholson Steam Trap line of industrial and process steam traps.
- 1990 Spence Engineering Company takes over the manufacturing of safety relief valves, from the Watts Industries Canadian division, and becomes certified by the American Society of Mechanical Engineers (ASME) as a manufacturer and assembler of safety relief valves
- 1998 Spence acquires the Ashcroft line of Temperature Regulator.
- 1999 Spence Engineering and Nicholson Steam Trap receive ISO-9001 certification as manufacturers of fluid control and steam specialty devices.
- 2001 Spence acquires the Rockwood Swendeman line of cryogenic safety relief valves.
- 2004 SSI Equipment, a fabricated strainer manufacturer, located in Ontario, Canada, is relocated to the Spence facility, in Walden, NY, and becomes Spence Strainers International and becomes ASME "U" Stamp certified.
- 2005 Spence Engineering incorporates "Six Sigma" lean manufacturing practices at its Walden, NY facility.
In 1999, CIRCOR International, of Burlington, MA, acquires the HVAC, oil, gas and instrumentation divisions of Watts Industries. Spence Engineering Company, Nicholson Steam Trap, Spence Strainers International and Rockwood Swendeman become divisions of the new corporation.
Today, Spence stands alone in its ability to produce self-contained regulators, for pipe connection sizes of 1/2 inch to 12 inch that require no external power source. We are the industry's leader in the steam regulation field, with sales offices throughout the United States, Europe, Asia, Central and South America and the Middle East. Spence regulators are used extensively in heating systems, institutions, public utilities, district heating systems, process systems and major industrial plants. Our products can be found in the Sears Tower, Time-Warner building and Rockefeller Center in New York City and in manufacturers facilities such as Ford Motor Company, General Motors and DuPont. Today, Spence continues it "History of Innovation" by continuing to develop and manufacture quality steam specialty and fluid control products and solutions for the HVAC and industrial marketplace.