Olyflow - Uflow Hercules RetroDrain w/Cast Alum Dome

The OMG Hercules Aluminum RetroDrains (SKUs HDAL3A, HDAL4A, HDAL5A, HDAL6A) are durable retrofit roof drains designed to replace existing drains in re-roofing projects without removing the existing drain fixture. Each drain features a one-piece spun aluminum body, heavy cast aluminum strainer dome, large flange for secure membrane attachment, and a U-Flow mechanical watertight seal that connects reliably to existing plumbing (PVC or cast iron). These drains meet multiple codes and standards and offer reliable, long-term performance.

Key Features

• one-piece spun aluminum body for strength and durability
• heavy cast aluminum strainer dome and clamping ring to prevent debris entry and ensure long life
• large 17.5-inch diameter flange with depressed sump area improves drainage and membrane flashing interface
• U-Flow mechanical seal provides watertight connection to existing PVC or cast iron drain lines
• long drain stem (12-inch) to accommodate field conditions; options for TPO or PVC coated flange available

• item numbers: HDAL3A (3-inch), HDAL4A (4-inch), HDAL5A (5-inch), HDAL6A (6-inch)
• drain body: 11 gauge (0.125-inch) spun aluminum
• flange diameter: 17.5-inches, with sump area
• stem length: 12-inches
• materials: cast aluminum strainer dome; aluminum body; clamping ring cast aluminum (for non-coated flanges)
• seal: watertight U-Flow mechanical seal, requires U-Flow screwdriver for installation
• packaging weight: 27 lbs each unit for all sizes (3-6-inch)

• Remove the existing strainer dome, clamping ring, and other drain parts so the roof membrane under the drain flange is clean and level.
• Insert the U-Flow seal into the end of the RetroDrain stem; adjust and cut stem if necessary to fit existing pipe, ensuring at least minimal stem length remains per manufacturer.
• Place assembled RetroDrain into existing drain leader so the flange lies flush with the roof membrane.
• Tighten the U-Flow seal screws evenly using the proper U-Flow screwdriver until hand tight; avoid over-tightening.
• Secure flange to deck with a minimum of three fasteners spaced evenly; ensure flashing membrane covers fastener heads. If using TPO or PVC coated flange, weld/flame-seal or heat-weld per membrane manufacturer.
• Install the clamping ring (if applicable), then place the strainer dome and secure it with provided screws.

Q: What sizes do the SKUs HDAL3A, HDAL4A, HDAL5A, HDAL6A correspond to?
A: They correspond to 3-inch, 4-inch, 5-inch, and 6-inch drain sizes respectively.

Q: What is the flange diameter of these RetroDrains?
A: The flange diameter is 17.5 inches with a depressed sump area.

Q: What type of plumbing can they connect to?
A: They can connect to existing PVC or cast iron plumbing via the U-Flow mechanical seal.

Q: What material is used for the body and dome?
A: The body is 11 gauge spun aluminum; the strainer dome and clamping ring are heavy cast aluminum.

Q: Are these units watertight to code?
A: Yes. They conform to relevant standards (ASME 112.6.4, CSA-B79-08, ANSI/SPRI RD-1) and include watertight U-Flow seal technology.