A PP (Polypropylene) Sight Glass is an industrial instrument used to visually monitor the flow, level, or condition of fluids within a piping system. Because the body is made of Polypropylene, these sight glasses are specifically designed for environments where metallic components would succumb to corrosion. Feature Typical Range / Detail Body Material Polypropylene (PP) / Glass-reinforced PP Viewing Material Borosilicate Glass, Acrylic, or Polycarbonate Size Range 15mm to 300mm (1/2' to 12') Pressure Rating Up to 10 Bar (approx. 145 PSI) Temperature Limit Max 80°C to 90°C (176°F to 194°F) Sealing / Gaskets EPDM, Viton, or PTFE (Teflon) End Connections Flanged (ANSI/DIN) or Threaded (BSP/NPT) Full-View (Tubular) Type: Features a 360° transparent tube. Best for checking fluid color, clarity, and the presence of bubbles from any angle. Double Window Type: Features a solid PP body with two opposite glass windows. More robust for slightly higher pressure applications and easier to shield with safety guards. Drip Tube / Flapper Type: Includes internal indicators (like a flapper or drip tube) to help visualize low-flow or vertical downward flow. ## Primary Applications Chemical Processing: Monitoring the movement of corrosive acids or bases. Water Treatment: Observing chemical dosing and filtration clarity. Fertilizer Plants: Handling aggressive liquid fertilizers. Pharmaceuticals: Visualizing flow in pure water or solvent lines. Food & Beverage: Checking for line drainage or product consistency. Polypropylene Flow Indicator Plastic Inline Sight Glass Acid-Resistant Sight Flow Corrosion Resistant Level Glass Borosilicate PP Sight Glass Flanged PP Sight Glass Valve