Test Kits For Petroleum Fluids. Direct reading. Install in any position. 360 degrees rotatable guard/scale. Easier-to-read linear scale. No flow straighteners or special piping required. Relatively insensitive to shock and vibration. Good viscosity stability. Temperature up to 240 degrees F. Accuracy +/-2 percent full scale. Repeatability +/-1 percent. Special scales available. Calibrated for 0.876 S.G. Materials: 2024 - T351 Anodized aluminum body, piston and cone. Common parts are Spider Plate: T316 SS, Spring: T302 SS, Fasteners: T303 SS, Pressure Seals: Viton, Guard: Polycarbonate, Retaining Ring: SAE 1070/1090 Carbon Steel, Retaining Spring: SAE 1070/1090 Carbon Steel, Indicator and Internal Magnet: PPS / Ceramic, Guard Seal / Bumper: Buna N, Scale Support: 6063 - T6 Aluminum and End Caps: Nylon ST. Reverse flow by-pass option: Features a two-piece cone that responds to flow in the primary flow direction in the same manner as the standard design. Flow in the reverse direction causes the lower cone shuttle to shift, moving it below the sharp-edged piston orifice. This shift creates a gap which allows the fluid to flow freely in the reverse direction.