Ultra-Rib Access Risers (RR, RU, RPU)
Ultra-Rib™ PVC 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 12-inch, 18-inch, and 24-inch nominal diameters
(300-mm, 450-mm, and 600-mm DN)
- Heights available in 3-inch (76-mm) nominal increments to 13 feet
(3.96 m) for 12-inch and 18-inch nominal diameter (300-mm and
450-mm DN) risers and 14 feet (4.27 m) for 24-inch
nominal diameter (600-mm DN) risers
- Bulk pipe available in 13-foot (3.96-m) sections for 12-inch and 18-
inch nominal diameter (300-mm and 450-mm DN) pipe and 14-foot
(4.27-m) sections for 24-inch nominal diameter (600-mm DN) pipe
HOW TO SELECT
Step 1: Determine the diameter of the riser needed for your application:
- Simplex pump systems require a minimum 24-in. diameter access riser.
- Duplex pump systems require a 30-in. diameter access riser.
- Effluent filters typically require a minimum 18-in. diameter access riser.
Note: We recommend a 30-in. diameter riser when the depth is greater than 3 ft.
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 3 in. above the
finished grade level.
Note: This includes 2 in. for settling in new installations. For existing installations, only
1 in. 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 1 in. or 1-1/4 in. SB1 through SB4 requires a 1-in.
grommet. SB5 and SB6 require a 1-1/4-in. grommet. Standard location for internal splice boxes is
6 in. down. External splice boxes require a 4-in. grommet 6.25 inches down. Discharge grommet is
18 in. down for tall risers (≥ 24 in.) and 6 in. up from the bottom for short risers (< 24 in.).