Samson Ringo has recently concluded the manufacturing and Factory Acceptance Test of a contract to be supplied to Thermosolar CSP Plant in China for Beijing Shouhang IHW Resources Saving Technologies Company through Samson Controls China.
This contract includes a control valve for molten salts service:
- Motor Operated Control Globe Valve 4” 300# BW ends
- Body: A351 CF8C – Trim: A182 F347H + Stellite hardfacing
- Maximum shut-off: 20 bar
- Maximum working pressure: 575ºC
Concentrated Solar Power (CSP) technology is based in the reflection and concentration of the sunlight energy in a tower where there is a receiver with molten salts that absorbs this energy and reaching temperatures close to 600ºC. These molten salts are storage and used to generate steam that produces the energy in a turbine.
Service Challenges and Ringo Solutions
For this particular severe service, there are some important technical challenges:
- Molten salts are highly corrosive at high temperature, in this case maximum working temperature is 575ºC
- Temperature can never goes below 265ºC because the salts became solid and valve could not be operated
Considering the above challenges, Samson Ringo considered the following features in the design:
- All used materials are suitable for the high temperature and all of them are corrosion resistance; even valve has been supplied with a special graphite live loading double packing that includes a sacrificial anode to avoid corrosion.
- On the other hand, in order to keep the minimum required temperature to avoid molten slats becoming solid, the valve includes an electric tracing system on the bonnet.