The knife-gate valve uses a steel gate like a blade that lowers into a slurry flow to create a bubble-tight seal. While conventional metal gates fill with hardened slurry and fail easily thereby requiring high maintenance, Clarkson's design introduced an easily replaceable snap-in elastomer sleeve that is durable, versatile, and handles both high pressure and temperature variation. Pipeline operators value Clarkson's elastomer sleeve because traditional seals have cost between $75 and $500 to replace, and considerable revenue is lost when a slurry system is stopped for maintenance repairs. Clarkson' product lasts longer and is easier to replace. In the late 1990s, the Clarkson Company was acquired by Tyco Valves & Controls, a division of Tyco International, Ltd. TYCO Valves & Controls, located in Reno, Nevada, and having ISO 9000 certification, continues to produce, market, and distribute products under the Clarkson brand name, including the popular knife-gate valve.
Discussion
1. The successful Clarkson knife-gate valve contains a wafer that is thin and light. Yet, the wafer is so strong it can operate with up to 150 pounds-per-square-inch (psi) of pressure on it, making it much stronger than those of competing brands. Suppose Tyco engineers have developed a new wafer that is