Fluidra - 3-Piece Union Nut D63/75 for Ø900 Sand Filter

Fluidra – 3-Piece Union Nut D63/75 for Ø900 Sand Filter

This is the genuine Fluidra replacement union nut for the 3-piece pipe union assembly, sized for D63/75 mm pipework. It forms the threaded locking collar that holds the two union halves together, enabling a secure yet fully demountable pipe connection on your pool filtration system. It is a direct OEM spare for the Fluidra Ø900 sand filter rated at 30,000 l/h with a 2½” port (valve-free version).

Compatibility

This union nut is designed specifically for use with the Fluidra Ø900 / 30,000 l/h 2½” sand filter assembly (without valve). It is sized for D63/75 mm PVC pipework, which is standard on large-format residential and semi-commercial pool filtration installations. Always verify your existing union body diameter before ordering to ensure a correct fit.

Why Genuine Matters

A genuine Fluidra union nut ensures precise thread tolerances and PVC material grade that match the original union body, delivering a leak-free seal without the need for PTFE tape between the nut and union end. Off-brand alternatives may have slightly different thread pitches or thinner walls, increasing the risk of cross-threading or joint failure under sustained pump pressure. Sourcing OEM ensures long-term reliability and pool-safe materials.

Installation

The union nut should be tightened by hand in most cases; however, for larger diameters such as D75, a strap wrench may be needed to achieve a proper seal without over-stressing the fitting. No solvent cement or PTFE tape is required at the nut-to-union interface — the integrated O-ring in the union body provides the seal. Ensure pipework is properly aligned before tightening, as these unions are not recommended where pipes are under bending stress.