Marathon 3 in. Pro Flo Aluminum Reroof Drain

The Marathon Pro Flo PFDS-3 is an aluminum retrofit/reroof drain that uses the MAXXFLO mechanical seal to lock into the existing drainpipe. It ships with a standard plastic strainer and clamping ring, and the drain body is constructed of heavy-duty gauge (.081) spun aluminum. The design speeds installation while avoiding disturbance to the existing roof assembly.

Key Features:

• Significantly faster installation
• MAXXFLO Tool (ratchet twister with cross pin) available for easy installation
• Standard clamping ring for additional membrane bonding; .081 spun aluminum drain body
• Installation does not disturb original roof assembly or interior finishes
• MAXXFLO mechanical seal helps prevent water back-up

• Part number: PFDS-3 (3″)
• Construction: Heavy-duty gauge (.081) spun aluminum
• Supplied components: Plastic strainer and clamping ring (metal strainer and clamping ring optional)
• Also available: Drain available in copper
• MAXXFLO seal color: Black and yellow
• MAXXFLO seal material: ABS and EPDM rubber
• MAXXFLO seal technical data (3″ size):
  • Weight: 0.42 lb (0.19 kg)
  • Inside diameter: 2.00″ (51 mm)
  • Low temperature impact (ASTM D-2136): −40 °C (−40 °F)
  • Brittle point (ASTM D-746): −57.8 °C (−76 °F)
  • Accelerated weathering (ASTM D-2565 Xenon): minimum 5,000 hours
  • Linear dimension change (ASTM D-1204): 0.0%
  • Change in weight after 24-hour water immersion (ASTM D-570): 0.0%
  • Seal water back-up pressure resistance: 35 kPa (≈ 3.56 m of water)

• Select the correct Pro Flo drain size (PFDS-3 for 3″).
• Insert the MAXXFLO seal into the drain pipe’s stem; use the castle head/ratchet to expand the top half of the seal so it locks to the drain stem.
• Place the assembled unit into the roof drain pipe.
• Tighten the castle head until the drain is properly fixed and leak-proof.
• If the leader pipe can’t accommodate the drain pipe stem length, cut the stem so about 2″ remains to accept the top of the seal; ensure an opening height of approximately 4″.

Q: What’s included with PFDS-3?
A: A plastic strainer and clamping ring are supplied as standard; metal versions are optional.

Q: What materials are used?
A: The drain body is heavy-gauge (.081) spun aluminum; the MAXXFLO seal is ABS and EPDM rubber.

Q: What sizes are available in the Pro Flo series?
A: PFDS-3 (3″), PFDS-4 (4″), and PFDS-6 (6″).

Q: What is the MAXXFLO Tool?
A: A ratchet twister with a cross pin that simplifies tightening the seal during installation.

Q: Does installation disturb the existing roof?
A: No — the design avoids disturbing the original roof assembly or interior finishes.