Valve material
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I would like to ask: the medium is clear lime water; the customer only mentioned that its concentration is high, the temperature is 60°C. It’s a DN100 butterfly valve with a soft seal – how should I choose the materials for the valve body, seat, and disc? Can EPDM be used for the valve seat? Please help
The medium is clear lime water, which is an aqueous solution of Ca(OH)2 and is alkaline. The solubility at 60°C is 0.116 g (in 100 g of water), and its Ca(OH)2 concentration is only 0.116%, which is very low. A regular carbon steel valve will suffice. For your reference, the solubility in water (100g) varies with temperature (in degrees Celsius) as follows: 0 degrees – 0.185g; 10 degrees – 0.176g; 20 degrees – 0.165g; 30 degrees – 0.153g; 40 degrees – 0.141g; 50 degrees – 0.138g; 60 degrees – 0.116g; 70 degrees – 0.106g; 80 degrees – 0.094g; 90 degrees – 0.085g
Thank you very much. The valve body is made of carbon steel; then for the valve seat, is it okay to use EPDM, since it’s a soft seal?
The valve seat can be made of EPDM – no problem. It is recommended that the valve disc be made of carbon steel coated with EPDM
Well, thank you. Why wrap it in EPDM? Is it to prevent carbon steel from corroding? Then the friend on the first floor just now suggested that the valve body be made of carbon steel – is a lining also necessary?