Pentair 181011 Clamp Assembly - NS/PF35 with Spring

Pentair part number 181011 was designed for older Pentair/Pac-Fab Nautilus NS and PF35 filter applications, including certain filters manufactured prior to 1991. Its spring-loaded clamp design helped simplify installation while applying even pressure around the tank seam.

A worn, bent, corroded, or improperly tightened tank clamp can create a serious safety concern. Never operate a pressurized pool filter with a damaged clamp, missing hardware, weakened springs, or cracked tank flange.

• Manufacturer: Pentair / Pac-Fab
• Original Part Number: 181011
• Part Type: Spring-style tank clamp assembly
• Clamp Size: Approximately 18 inches
• Original Application: Select Nautilus NS and PF35 D.E. filters
• Original Hardware Included: Clamp halves, springs, nuts, and washers
• Status: Discontinued and no longer available from Pentair

This clamp assembly was commonly associated with legacy Pentair/Pac-Fab Nautilus NS filter systems and PF35 filter configurations. It may be referenced on older NS24, NS36, NS48, NS60, and NS72 filter systems depending on the exact tank generation and clamp configuration.

Important: Do not select a replacement clamp based on diameter alone. Tank flange profile, clamp width, hardware location, spring configuration, and the filter’s manufacturing generation must all match. A clamp that appears visually similar may not safely fit your filter.

Because the complete Pentair 181011 clamp assembly is discontinued, replacement should be approached as a safety-critical repair rather than a generic hardware substitution.

• Inspect the tank halves and sealing flange for cracks, warping, or damage.
• Confirm whether the original clamp band itself is reusable and whether only the spring/hardware components need replacement.
• For certain older stainless-clamp Nautilus filters, individual clamp hardware may be serviceable with the correct matching bolt, nut, spring, and washer configuration.
• If the clamp band, tank flange, or tank body is damaged, a complete compatible filter replacement may be the safest path.

Contact Aqua Terra Backyard with your filter model, serial number, tank diameter, and photos of the existing clamp and tank seam for help identifying the most practical replacement path.

• Turn off the pump and fully relieve all filter pressure before servicing.
• Open the filter air-relief valve before removing any clamp hardware.
• Inspect the tank O-ring and sealing surfaces during every clamp service.
• Use only hardware designed for the specific filter and clamp configuration.
• Do not overtighten clamp hardware or use damaged springs, bent bands, or mismatched fasteners.
• After reassembly, stand clear of the filter while restarting the pump and inspect carefully for leaks.

Is Pentair 181011 still available?
No. Pentair 181011 has been discontinued and is no longer available as a current OEM replacement part.

Can I use a universal filter clamp instead?
Not recommended. Filter tank clamps are safety-critical components and must match the exact tank design, flange profile, hardware arrangement, and filter generation.

Can I replace only the springs or hardware?
Potentially, but only when the existing clamp band and tank flange are structurally sound and the replacement hardware matches the original clamp design exactly.

What information do I need to identify a solution?
Send photos of the entire filter, the clamp seam, the existing clamp hardware, the filter label, and the tank diameter. This helps confirm whether a hardware rebuild or a larger replacement path is appropriate.