William Elvis Sloan (1867 - 1961)，冲水阀发明家，也是美国思龙阀门公司的创始人，出生于美国密苏里州。在完成了管道安装工的学徒学业后，他来到芝加哥，历任领班，主管，最后，成为独立的承包商。通过刻苦自学，思龙先生掌握了电力学和水利学的高级理论，在他长寿、多产的一生中，共创造了64项发明。其中包括电报线路的继电调压器和剧院防火帘。后一个发明是受到发生在芝加哥的Iroquois剧院大火灾难的启发，这场灾难有几百人遇难。这场大火从后台开始，迅速蔓延到观众席上。思龙先生的发明是一种采用可熔断挂钩的防火帘，当出现火灾时，会立即自动的掉落悬挂下来，阻挡大火蔓延。这种发明就像大多数发明一样，简单实用，点破不值钱。
　　The inventor of the Flushometer and founder of Sloan Valve Company was born in Liberty, Missouri. After serving as an apprentice pipe fitter, he traveled to Chicago and became a foreman, a superintendent, and finally, an independent contractor.
Through intense self-education, Mr. Sloan developed a superior knowledge of electrical circuitry and hydraulics, which led to a total of 64 inventions during his long, productive life. Among these were a relay booster for telegraph lines and a fire-safety curtain for theaters. The later invention was inspired by the Iroquois Theater fire in Chicago, which claimed hundreds of lives. The fire started backstage and spread rapidly into the auditorium. Mr. Sloan's conception was a fireproof curtain with heat fusible linkage, which would drop instantly and automatically in the event of a fire; it was simple, practical and, like most good inventions, immediately obvious-once somebody thinks of it.

　　思龙先生随后对Royal冲水阀的发明进行改进和创新，使得这种冲水阀设计更加先进科学、更加简单易用。Royal冲水阀是一种隔膜式阀门，是美国思龙阀门公司最早的产品，从1906年就开始生产。现在仍然是思龙公司产品线中销售量最大的冲水阀（在世界各地，使用着几百万个这类冲水阀）。随着时代的进步，这类冲水阀部件有了许多的改进，制作越来越精致，但是，其工作原理和基本的水利学设计结构仍然没有改变。
　　Mr. Sloan then developed the idea for the Royal Flushometer with its revolutionary design and ingenious simplicity. The Royal is a diaphragm-type valve and was the original product of Sloan Valve Company when it started in business in 1906. It is still the largest selling Flushometer in the Sloan line (literally millions are in use throughout the world). While there have been many refinements and improvements in component parts over the years, the working principle and fundamental hydraulic design have not changed.

　　自从思龙先生创立公司以来，在冲水阀行业内，还没有任何公司能够在销售量上超过思龙，甚至没有公司有足够的勇气面对思龙的抵抗和可能遭遇的挫折。在商用建筑结构中，采用冲水阀替代马桶水箱，其优势是显而易见，无法否认：节水，日常维护少，相对较少破损和故意损坏，在相继两次冲水之间几乎不需要等待时间。这些优点对于建筑物的日常维护都大有好处。但是，要采用这种冲洗阀，就要付出比较高的初始成本，因为供应冲水阀的管道通常要比马桶水箱所需的管道直径要大。
　　No figure in our industry ever faced a greater sales challenge than Mr. Sloan in launching his new company, and none ever persevered more courageously in the face of resistance and discouragement. The benefits of using Flushometers instead of toilet tanks in commercial structures were considerable and undeniable: a saving of water, much less maintenance; a relative freedom from breakage and vandalism, and virtually no recycling time between flushes. These benefits would pay every day for the life of the building. But to get them, you had to accept a somewhat higher initial cost because the pipe size of the branch line supplying the fixture had to be larger than that required for a toilet tank.

　　思龙先生所需要面对的实际困难在于人们安于现状的阻力。管道工由于对冲水阀知之甚少而不敢安装冲水阀，建筑师也由于同样的原因不敢采用冲水阀，而房屋业主也不想自己作为别人的试验品，出租人不想采用未经证实的产品。有些卫生洁具制造商甚至拒绝在他们的洁具上安装思龙冲水阀。
　　But the real problem Mr. Sloan had to overcome was the normal human resistance to change. Plumbers were afraid to install Flushometers because they knew nothing about them. Architects would not specify them for the same reason. Owners did not want to be the guinea pigs. Lenders were leery of unproven products. Some fixture manufacturers even refused to furnish their fixtures when Sloan Flushometers were to be installed.

　　第一年，思龙先生只卖出一个冲水阀，是的，只有一个！第二年，它的销售量增加了一倍，卖了两个。第三年，情况有了改观，他卖出了150个冲水阀，从此，销售量直线上升。只要建筑工程师允许，思龙先生就展示性的安装冲水阀，让工程师们看看能够为他们带来多少节约和好处。实践证明冲水阀的优点是多么的无与伦比，顾客也开始改变了原先的观念。
　　The first year he sold one Flushometer - that's right, one! The next year he doubled his business and sold two. In the third year a phenomenal advance was made; he sold 150 Flushometers and from then on sales shot upward. Whenever a building engineer would permit, Mr. Sloan would install Royal Flushometer for demonstration, and let him see the savings and benefits for himself. The flush valve proved so incomparably better that the trade began to relax its opposition.

　　思龙先生还开发了活塞式冲水阀。经过几年的发展，在最早的Royal系列冲水阀的基础上，又增加了Star系列、Crown系列、Gem系列和Naval系列，除此之外，还有自动小便斗冲水阀系列和Act-O-Matic淋浴花洒系列。思龙先生通过在管道产品行业、建筑行业和社会公共机构领域的出版物上，在任何可能的时候或位置上的强有力的、持续不断的广告，使得他的名字成为冲水阀行业的代名词。
　　Mr. Sloan also developed piston-type Flushometers. Over the years, the original Royal was joined by the Star, the Crown, the Gem and the Naval; plus automatic urinal flushing systems and the Act-O-Matic showerhead. He made his product names bywords in the industry through powerful, consistent advertising in plumbing, architectural, and institutional publications, using cover positions whenever available.

　　思龙先生在他93岁生日过后不久逝世。他所创建的公司今天已经成为世界冲水阀的领导者。他的生产车间和工厂是行业内最现代化、最高效的。
　　Mr. Sloan died just short of his 93rd year. The company he founded and built is today the world leader in Flushometers. Its foundry and plants are among the most modern and efficient in the plumbing industry.