Pentair Clamp Knob

The Pentair Tank Clamp Knob (primarily part number 076033Z for post-1998 5/16" configurations, 071136Z for legacy pre-1998 systems, or WC36-22 for Sta-Rite/Max-E-Pro adaptations) is a specialized external mechanical fastener engineered exclusively to tension the structural split-tank clamp rings of residential pool and spa filtration vessels and high-performance pumps. This ergonomic tightening component is used across a broad spectrum of equipment lines, including Pentair Nautilus Plus, Purex SM/SMBW 2000 and 4000 series Diatomaceous Earth (D.E.) filters, Cristal Flo sand filters, and Sta-Rite Posi-Flo II cartridge filters, as well as WhisperFlo, Max-E-Pro, and IntelliPro pump bodies.

Injection-molded from a heavy-walled, high-impact, and UV-stabilized engineering thermoplastic composite, the exterior shell features large contoured wings or heavy ribbing to maximize human hand leverage during manually torqued assembly. The internal core houses a precision-tapped metal thread matrix configured to spin smoothly down onto the clamp band’s heavy-duty structural carriage bolt or tie-rod stud. Its primary operational role is to close the gap of the perimeter tension hoop, uniformly crimping the upper and lower halves of the pressurized tank chassis tightly over the main sealing o-ring. By eliminating localized pressure gaps without the use of hand tools, it establishes an absolute watertight compression boundary that ensures the high-pressure filter tank can safely contain its internal fluid dynamics and sustain continuous system operating parameters up to 50 PSI without weeping, leaking, or experiencing catastrophic lid separation under severe pump startup surges.

Designed to live in the harsh environmental conditions of an outdoor pool equipment pad or damp commercial pump room, its rugged composite housing shields the internal metal threads from airborne moisture and direct chemical splashing, effectively preventing thread galling, binding, and advanced oxidation. The advanced polymer matrix completely resists material softening, structural deformation, and chemical cracking from direct exposure to UV radiation and pool sanitizers like chlorine and bromine. Due to its lightweight, hollowed plastic shape paired with a compact internal metal threading insert, this individual replacement clamp knob carries a nominal net product and shipping weight of approximately 0.05 to 0.15 pounds (about 0.80 to 2.40 ounces).