CCI Technology Never Doubted at Dow

Companies they rely on plant operation don’t gamble when it comes to their severe service valves; they need a solution they can trust. And such trust can only be established through time-tested performance.

For several years now, CCI and Dow Olefinverbund GmbH, Site Böhlen, a leading science and technology company, have been building a solid relationship based on Dow’s trust in CCI’s severe service solutions. The partnership began as CCI completed several projects with Dow at its Central Germany facility to solve the plant’s control valve problems and upgrade its severe service valves with CCI’s 100DSV (spraywater) product line.

CCI’s DRAG® spraywater valves protect valve components and ensure reliable system performance by controlling velocity. The specially designed DRAG® disk stack eliminates damage caused by erosion and cavitation while ensuring long-term, tight shutoff and reduced maintenance costs. As part of Dow’s push to optimize the plant’s profits by improving plant equipment, the customer purchased most of its new spraywater valves to replace existing equipment.

CCI customized its 100DSV design to suit various applications, including feedwater regulator, high-pressure pump recirculation, and spraywater attemperator, at Dow’s Central Germany facility. All of the CCI valves boasted spring diaphragm actuation and were characterized with trim sizes of 1.5 inches (38 mm) or smaller to provide optimal valve performance at all flow conditions.

Through the years, these installed solutions at the Dow Central Germany facility minimized ownership costs and eliminated production downtime. Thus, with respect for CCI’s excellent customer care and trust in its equipment, Dow turned to CCI once again in 2002 when the company began upgrading its facilities.

One of the many systems that Dow selected to upgrade was the steam vent system, which consisted of a steam vent valve and a steam vent silencer. The primary purpose of the vent system is to vent steam during plant startup. Steam, used for warming the process pipes, would first be cycled through the process piping system and then vented to the atmosphere via the steam vent system. Because the amount of steam would increase over time, the valve required high rangeability to provide the smooth control necessary for the gradual heating process. Secondly, the steam vent system was responsible for venting steam if the pipeline temperature increased to critical limits.

Dow’s existing equipment incurred occasional problems that caused several maintenance headaches. Additionally, new environmental laws limited valve noise levels to 85 dBA and silencer noise levels to 75 dBA at 328 feet (100 meters) from the source. Finally, reliability was a critical concern, for the new system was responsible for carrying out an emergency vent without attracting the attention of local authorities.

After studying the vent system from an operational standpoint, CCI concluded that the optimal solution, from both technical and cost perspectives, required that half of the pressure drop occur across the valve and the remainder across the resistor. Thus with inlet pressures of approximately 90 BarG, the valve and resistor would each encounter a change in pressure of 45 Bar.

Valve sizing equations based on ISA-recommended industry standards revealed that the valve must be equipped with 10 pressure-reducing stages to lower the trim exit velocity head below ISA’s recommended value of 70 psi and to keep valve-generated noise under 85 dBA. Striving to minimize costs due to piping modifications, CCI supplied a 4 x 6-inch (100 x150-mm) valve rated to a 2500 ANSI pressure class. Constructed out of ASTM A217 WC9 material, the steam vent valve included a 2.5-inch (64-mm) trim built of ASTM A182 F11 and Iconel 718 material to withstand the extremely high inlet temperature (968ºF / 520ºC) associated with the steam flowing across the valve.

After selecting a solution for Dow’s steam vent valve, CCI’s next task was to select a device that would vent steam while staying below the stipulated noise level of 75 dBA at 328 feet (100 meters) from the noise source. For this, CCI introduced Dow to CCI’s improved version of the vent silencer – the DRAG® resistor. Designed with CCI’s revolutionary DRAG® technology, the DRAG® resistor is essentially a DRAG® disk stack surrounded by a V-shaped shroud that directs noise toward the atmosphere.

What differentiates the DRAG® resistor from a typical silencer is that, while a silencer’s performance deteriorates over time due to the wearing of the lagging material, a resistor has no lagging material and maintains a high performance level over time. As the fluctuating German weather can quickly take its toll on wearable items, Dow was thrilled with CCI’s guarantee that the DRAG® resistor’s performance would not decline through the years. CCI manufactured a resistor using 400-series stainless steel material and 50 stages of pressure reduction, measuring just 36 inches (914 mm) wide and 10 inches (254 mm) high.

Just as CCI’s spraywater solutions have improved plant performance and proven their value over the years, CCI’s newest solutions at Dow’s Central Germany facility – the DRAG® steam vent valve and DRAG® resistor – have delivered the results promised by CCI. Nearly two years after CCI installed the new steam vent system, Dow continues to enjoy the benefits of quiet, reliable service. Time and time again, CCI’s DRAG® technology has successfully addressed some of the most severe applications in the industry.

Published in Summer Solutions 2004