The Stark S-500 Threaded Closure represents historically the most widely used closure style in the oil and gas sector. Based on the industry’s desire for robust and cost-effective solutions, Stark improved upon the standard design to bring operation to a new level. Features to avoid hammering and strengthen operator control were incorporated into the otherwise proven design. The S-500 is manufactured in diameters ranging from 2” to 52” (DN50 to DN1300) and pressure series 150 through 2500.