Marathon Roofing Products - Poseidon SS Retrofit Drain - with CI Ring and Dome

The Marathon Poseidon SS Retrofit Roof Drains CI series (BSS3CI, BSS4CI, BSS5CI, BSS6CI) combine a stainless steel drain body with a cast iron ring and dome for maximum strength and durability. Designed for retrofit use, these drains feature a 17-gauge Type 304 stainless steel body, heavy cast iron ring and dome, and are supplied with a ProSeal rubber or tape seal. With a standard 16-inch flange and 12-inch outlet across all sizes, this series is built to deliver reliable performance in even the harshest environments.

Key Features:

• Stainless steel body with cast iron ring and dome
• Available in 3″, 4″, 5″, and 6″ outlet sizes (BSS3CI–BSS6CI)
• Supplied with ProSeal rubber or tape seal for backup prevention
• Uniform 16″ flange diameter and 12″ outlet length across all sizes
• Built to withstand demanding conditions, including coastal exposure

• Body material: 17-gauge Type 304 stainless steel
• Ring and dome material: Cast iron
• Flange diameter: 16 inches
• Outlet length: 12 inches
• Sizes available: 3″, 4″, 5″, 6″
• Seal options: ProSeal rubber seal or tape seal
• Approximate weight: 8.25 lbs

• Select the correct model (BSS3CI, BSS4CI, BSS5CI, or BSS6CI) based on outlet pipe size.
• Remove existing drain dome and clean the surrounding area.
• Place the new Poseidon drain so the 16-inch flange sits flat on the membrane.
• Install the ProSeal or tape seal securely around the outlet.
• Position the cast iron ring and dome and secure with the provided hardware.
• Flash or weld the flange into the roofing membrane according to the roofing system.

Q: What does “CI” mean in the part numbers?
A: “CI” indicates these models use a cast iron ring and dome paired with a stainless steel body.

Q: What materials are the body, ring, and dome made of?
A: The body is 17-gauge Type 304 stainless steel; the ring and dome are cast iron.

Q: What are the flange and outlet dimensions?
A: All models include a 16-inch flange and a 12-inch outlet.

Q: What seal options are included?
A: Each drain comes with either a ProSeal rubber seal or a tape seal.

Q: Are these drains suitable for coastal environments?
A: Yes, the stainless steel and cast iron construction provides high corrosion resistance.