A. The recommended design described below is provided to describe the modifications for each manhole. The Contractor may vary the design only after providing a detailed plan of such variance and receiving approval from the Engineer and Owner. B. Materials: 1. Frame and Cover: a. LSP 162 – Heavy Traffic Type Sanitary Manhole Frame and Cover 2. Sanitary Sewer Inflow Protector: a. 24-inch diameter to fit specified ring and cover (filed measure and verify exact diameter of MH rings) b. Corrosion proof HDPE or equal c. Bottom sealing gasket d. One-way gas diffuser valve to allow for release of gas at a pressure of 1 psi or less. Valve to be installed on the upper outer edge of inflow protector. 3. Adjustment Rings: a. Precast reinforced concrete grade adjustment rings complying with ASTM C 478, free from cracks, voids and other defects. 4. Adjustment Risers a. Precast reinforced concrete grade adjustment rings complying with ASTM C 478, free from cracks, voids and other defects 5. Eccentric Cone: a. Reinforced precast concrete in accordance with ASTM C 478 C. Reference City of Lincoln’s Standard Specification Chapter 22 Sanitary Sewers for additional instructions and materials...
