Banjo Polypropylene Bolted Ball Valves Flange Ports. MV100CF, MV200CF, MV220CF, MV300, MV300CF. FKM (viton type) seals. PTFE self-lubricating stem bushings and seats cannot stick or bind. Precision moulded in polypropylene. Polypropylene is reinforced with fiberglass for additional strength. Self-aligning ball moves freely against the PTFE seats for smooth operation. The valve opens and closes with very little pressure on the handle. Ball is diamond turned, after moulding, to make it spherically perfect, which provides precise contact between ball and seats.