Ultra-Rib-Style Access Risers (RR, RU, RPU) 
Orenco Ultra-Rib-Style Access Risers are used to provide access to tanks and also as valve enclosures in water and wastewater systems. Bulk quantities are available.
- PVC construction
 
- Concentric rib design
 
- Available in 12in, 18in, and 24in nominal diameters (300mm, 450mm, and 600mm DN)
 
- Bulk pipe available in 13ft (3.96m) sections for 18in nominal diameter (450mm DN) pipe and in 14ft (4.27m) sections for 24in nominal diameter (600mm DN) pipe
 
HOW TO SELECT
Step 1: Determine the diameter of the riser needed for your application: 
- Simplex pump systems typically require a minimum 24in diameter access riser. 
 
- Duplex pump systems typically require a minimum 30in diameter access riser.
 
- Residential Effluent filters typically require a minimum 18in diameter access riser. 
 
Note: We recommend a 30in diameter riser when the depth is greater than 3ft. 
Step 2: Verify that the riser diameter is compatible with the riser tank adapter and tank hole size. 
Step 3: Determine the height of the riser. The top of the riser should extend a minimum 3in above the finished grade level. 
Note: This includes 2in for settling in new installations. For existing installations, only 1in above grade is necessary. 
Step 4: Determine requirements for splice box and grommet. For grommets used with internal splice boxes, determine the nipple size being used, either 1in or 1-1/4in SB1 through SB4 requires a 1in grommet. SB5 and SB6 require a 1-1/4in grommet. Standard location for internal splice boxes is 6in down. External splice boxes require a 4in grommet 6.25in down. Discharge grommet is 18in down for tall risers (≥ 24in) and 6in up from the bottom for short risers (< 24in).