Mermade 30" Round (4-17/32" Hub) Zipper Closure, Complete

The Mer-Made 30" Round Complete Vacuum DE Filter Leaf Assembly (4-17/32" Hub, Zipper Closure) is a circular commercial drop-in replacement element engineered for legacy cylindrical vacuum DE filter pits and round-tank commercial filtration systems (including classic Swimquip, B/K, and legacy Mer-Made round-tank arrays).

In this configuration, the circular disc frame measures 30" outside diameter (O.D.) and features an oversized central effluent manifold hub with a 4-17/32" outer diameter hub bore/collar (approx. 115 mm). It is supplied factory-clothed with a tailored, heavy-duty marine-grade zipper closure synthetic fabric bag that zips smoothly around the perimeter seam to maintain drum-tight cloth tension across the circular face.

Technical Specifications & Dimensions

Structural Architecture & Construction Details

• Radial Flow Drainage Matrix: Molded polypropylene or ABS structural disc core engineered with radial drainage spokes converging inward toward the center 4-17/32" collector hub. Resists inward face collapse under continuous vacuum loads up to 15" Hg.

• 4-17/32" Center Hub Interface: Precision-machined Schedule 80 PVC or molded hub ring engineered to slide over circular vacuum DE collector pipe headers. Machined internal/external gasket grooves accommodate elastomeric O-rings or flat gaskets to isolate the vacuum manifold from tank water.

• Perimeter Zipper System: Heavy-duty, corrosion-proof polymer teeth zipper (Delrin/nylon with locking slider) running along the outer circumference seam. Allows field operators to zip the cover tightly over the circular rim, providing uniform radial tension and preventing the fabric bagging common with drawstring or lace-up round styles.

• Tailored Polypropylene Septum Jacket: Factory-fitted, woven monofilament or multifilament polypropylene fabric calibrated for 20–30 micron diatomaceous earth pre-coat retention. Resists rot, chlorine shock, and dilute acid descaling baths.

Physical Dimensions & Weight Estimates

• Individual Complete Leaf Net Weight: Approximately 9.5 to 12.0 lbs (4.3 to 5.4 kg).

• Single Boxed Leaf Shipping Weight: Approximately 15.0 to 18.5 lbs (6.8 to 8.4 kg) in flat square corrugated cartons (approx. 33" × 33" × 4") with corner and edge protectors.

• Commercial Grid Lot (10 to 20 Leaves): Approximately 160 to 290 lbs (73 to 132 kg) freight-stacked and banded on a standard 40" × 48" or 48" × 48" wooden skid.

Field Installation & Shaft Stacking Guidelines

1. Clean Center Manifold Shaft: Wipe and wire-brush the central vacuum manifold pipe to remove accumulated calcium scale, calcified DE, and mineral burrs that could gouge the 4-17/32" hub seals.

2. Inspect Hub Seals & Spacers: Slide the replacement sealing ring or gasket over the shaft ahead of the leaf (or verify internal hub O-ring seating inside the 4-17/32" bore).

3. Slide Leaf onto Center Shaft: Guide the complete 30" round element onto the center manifold shaft through the 4-17/32" hub, seating it squarely against the preceding manifold spacer or shoulder.

4. Verify Zipper Security: Ensure the perimeter zipper slider is fully closed and tucked into its protective pocket/flap so it does not catch on adjacent leaves.

5. Torque Stack Compression: Once all round leaves and inter-element hub spacers are stacked onto the center shaft, tighten the end compression plate or tie-rod assembly to compress all hub gaskets and establish a vacuum-tight seal across the entire manifold stack.