Pentair 9.25" V-Clamp Kit with Knob

The Pentair Sta-Rite 9.25" V-Clamp Kit with Knob (part number WC119-87 or WC119-87Z) is a high-pressure mechanical fastening mechanism engineered exclusively to lock critical multi-port control valves to their underlying tank structures. This genuine original equipment manufacturer (OEM) structural replacement kit is standard hardware designed specifically for the unique 9.25-inch perimeter flange union found on Pentair Sta-Rite Cristal-Flo® T-BP Series high-rate sand filtration vessels, Waterford filtration configurations, and matching 1.5-inch top-mount multi-port backwash valves (such as the WC112-148 valve layout).

Primary Operational Role

The primary function of this heavy-duty V-clamp ring is to establish an unyielding, uniform mechanical seal across the high-stress junction where the top control valve mates with the filter tank neck. It features a continuous, contoured V-shaped profile along its interior radius. When positioned over the overlapping lips of both the valve body and the filter tank flanges, the clamp completely wraps around the perimeter channel. As the user tightens the integrated heavy-duty threaded bolt using the oversized, ergonomic plastic adjustment knob, the internal V-angle wedge pulls the two components tightly together in an absolute parallel compression alignment.

This mechanical wedge effect forces the components into a high-density, airtight and watertight seal directly over the underlying elastomeric flange O-ring. By ensuring an even, 360-degree perimeter hold, the clamp prevents the top-heavy valve assembly from shifting, weeping, or leaking during pressurized backwash, rinse, or filtration cycles. It safely absorbs severe pump startup thrusts and can continuously withstand intense hydraulic system operating parameters up to 50 PSI without risking physical valve separation or hairline seam leaks.

Engineering Material Properties

Fabricated from high-tensile, heavy-gauge stainless steel or premium corrosion-resistant electroplated metal bands, the V-clamp is engineered to endure decades of direct outdoor pool pad weathering and intense seasonal thermal cycling. Its resilient metal matrix completely resists stretching, thread-galling, and structural distortion, while its composition prevents advanced oxidation or chemical stress-cracking from constant exposure to corrosive vapors like chlorine, bromine, and localized chemical splattering. Due to its solid metal bands, integrated hinge points, heavy-duty tracking guides, and thick composite knob, this direct-fit replacement connection kit carries a net product and shipping weight of approximately 1.20 to 1.50 pounds (about 19.2 to 24.0 ounces).