24" Btm Mt Hub & Lat, 4-8" Thd, 2" Slip

The Pentair 24" Bottom Mount Hub & Lateral assembly is a flow-distribution underdrain built for 24-inch treatment tanks, featuring a 4–8" threaded hub connection and a 2" slip outlet. This is the component that sits on the floor of a large media vessel and collects treated water evenly from across the entire bed—the unsung part that ultimately determines whether a big filter actually performs to its rated capacity or quietly underdelivers.

A hub-and-lateral underdrain works by radiating a set of slotted laterals outward from a central hub. As water passes down through the media, the laterals draw it off uniformly across the full 24" diameter, preventing the channeling that robs capacity, causes early breakthrough, and wears media unevenly. The same network also distributes backwash water evenly across the floor of the tank, so the bed lifts and fluffs uniformly during regeneration rather than tunneling. The 4–8" threaded hub accepts the riser connection, while the 2" slip outlet ties into larger service plumbing with a solvent-weld joint that doesn't throttle flow—exactly what you want on high-volume softeners, carbon filters, and multimedia beds where service flow rates are substantial and pressure drop matters.

• Designed specifically for 24" diameter treatment tanks
• 4–8" threaded hub connection
• 2" slip outlet for high-flow service plumbing
• Even bottom-bed collection to prevent channeling
• Robust 4.1 lb hub-and-lateral construction
• Genuine Pentair tank-division underdrain

This underdrain is the right choice when you're building a new 24" commercial or large residential filter, converting a tank to a different media, or replacing a hub-and-lateral that has cracked, clogged, or lost laterals over time. When loading the tank, lay a gravel underbed sized to the lateral slots so fine media stays put and the screen openings don't blind off. Because the laterals screen the media and balance flow across the whole tank, a sound underdrain directly affects treatment quality, the run length between backwashes, and the working life of your media—three things that drive both performance and operating cost. For installers assembling Pentair 24" tank systems, this bottom-mount hub and lateral is the dependable foundation that lets the rest of the system deliver clean, fully treated water at full rated flow, year after year.