Full-Lined PTFE butterfly valves SB71 PN16 DN50~DN300 were used for Acid Storage System in Tolyatti, Russian

Project Requirements:
The customer declared that the conventional valve materials were inadequate due to the corrosive nature of concentrated sulfuric acid, special attention should be paid to the selection of valve sealing materials. FEP(F46), PTFE, PFA could be considered. The working temperature would be up to 135℃. The thickness of fluorine lining on disc and seat should not be less than 3mm. The supplied valves should be economical, practical, and easy to maintain.

Seallon`s Solutions:

● Considered the working temperature max to 150℃, we selected PTFE as the the material for contact medium, which had excellent acid and alkali resistance, while ensuring that no deformation below 150 ℃;
● FEP(F46) withstand max to 120℃, PFA up to 180℃, but was much expensive, so PTFE was the most optimal option for this order, meanwhile SB71 lined BTV contained the packing and packing gland; 
● A common problem with fully lined butterfly valves could not bear pressure higher than 1.0 Mpa, but Seallon`s SB71 lined BTV could bear up to 1.76 Mpa at room temperature; 
● The thickness of PTFE lining on disc and seat should be more than 3mm, for such sizes from DN200, the thickness could reach 5mm or more, bodies were covered by epoxy coating ≥250μm;
● Wafer connection was an economical structure for butterfly valves, we also supplied parts of discs and seats for replacement.

KEY WORDS: 
#SB71, #full lined butterfly valve, #FEP, PTFE, PFA, #thickness of fluorine lining, #bearing pressure performance, #replacement, #packing gland