Salt Dome Shut Off

Solutions

Mont Belvieu, TX

In an environmentally critical application the Chromatic HCV valve was chosen as the primary shut-off valve for Salt Dome storage.

Valves Supplied
Size 2" and 6" ANSI 600 Class
Body Material ASTM A-351 Grade CF8M (cast 316 SS) body with 316 SS
Internals 17-4PH stainless steel trim
Trim
Port
Connections
Service Conditions
Media Saturated brine and salt debris
Manual/Actuated Gear Operated
Temperature
Orientation
Pressure 400 to 800 psig
Cycle Frequency 3 to 4 times daily

Underground storage caverns are an integral part of the Texas economy, but require the best operating procedures and technology available to help assure public safety. These caverns are huge dome-shaped salt formations 1000 feet or more beneath the surface used for storage, and are carefully managed to safety standards and practices adopted by the Texas Railroad Commission to protect the public and the environment.

Shutoff valves for lines to and from cavern wells are some of the most important equipment required for reliable and safe operation. So when one Houston area operator chose valves for brine storage wells, they selected the Chromatic HCV Valve.

The unique patented design of the HCV valve combines benefits of quarter turn valves with the durability of gate valves. They are uniquely suited for shutoff applications for the salt dome storage wells, which encounter saturated brine with solid chunks of salt.

This particular Chromatic customer installed two valves for their salt dome storage terminal. One is a 6 inch full port ANSI 600 Class valve installed in the main brine line on the storage well. Brine is pumped into the well cavern to force the butane out of the cavern. When butane is pumped into the cavern, the brine is forced out. The installation also has a 2 inch full port ANSI 600 Class valve installed as a bypass to the 6 inch valve. The 6 inch valve sees a normal operating pressure of 400 psig and a maximum pressure of 800 psig applied from the well side, with the potential of 200 psig differential pressure applied from the opposite direction. The normal flow in the 6 inch valve is 800 gallons per minute.

The 2 inch bypass valve may see a normal flow of 300 gallons per minute with a high initial velocity as the valve is opened. A unique operating aspect of the HCV Valve cartridge permits slow opening to protect the valve internals from excessive wear due to the high velocity. The valve is operated on average three times per day. The 2 inch valve in this particular installation has an ASTM A-351 Grade CF8M (cast 316 SS) body with 316 SS and 17-4PH stainless steel trim. Both valves are gear operated.

The Chromatic HCV Valve utilizes a tapered hemispherical closure member (hemi) which rotates around a fixed core and wedges into a fixed seat to affect a seal. The design provides a positive, bi-directional, bubble-tight shutoff due to the tapered hemi wedging into the seat during the final 10 to15 degrees of travel.

The constant, fixed position of the core within the body provides protection of the seating surfaces when the valve is opened and minimizes turbulence as the valve is opened or closed, compared to designs with a rotating ball or plug. The rotation only stem results in low emissions compared to rising stem or rising and rotating stem designs. In addition, the valve may be operated significantly faster than rising stem valves.

The HCV Valve’s defining feature is its ‘cartridge design’ whereby all the valve’s internal parts (core, hemi, seat, stem, bushings) are affixed to the bonnet and may be removed by simply unbolting the bonnet fasteners. This allows quick and easy serviceability reducing downtime for maintenance. No special tools are required for replacement of the cartridge and there is no routine lubrication required in normal operation.

Six months after installation of the HCV valves, the salt dome operator removed the cartridges from the valves for inspection. Upon removal of the cartridge, the internal cavity and seat surfaces were inspected. The body was clean and free of debris, and a new cartridge was installed. This entire process, to the surprise of the Operator’s supervisors, took less than 15 minutes with no special tools.

Product Used

HCV Valve

The HCV valve (HEMI cartridge valve) is an innovative design that incorporates many positive features from other valve types. These features are combined into a single product platform that is UNIQUE to the Chromatic HCV product line and not found in any other valve on the market. The HCV is highly adaptive to a variety of process applications from...

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