Mermade 48" Tubular Keene-Bowser, Cover Only

The Mer-Made 48" Tubular Vacuum DE Filter Element (Keene-Bowser Replacement) — Cover Only (cataloged under Part # 775-COVER / VFC-48TB or Filter Sock) is the replacement cylindrical fabric sleeve designed to re-cover extended-length support cores in deep-bed legacy Keene-Bowser (Bowser-Briggs / Keene Corporation) commercial vacuum DE filtration systems, pressure-leaf conversions, and industrial process vaults.

Engineered to fit 2-1/2" to 3" outer diameter cylindrical cores across a 48" span, this tubular sleeve supplies only the woven synthetic filtration cloth, top/bottom attachment hems, retention clamps or ties, and replacement base sealing gaskets/O-rings. It is specified when the internal perforated Schedule 80 PVC/CPVC or polypropylene core tube and welded end-caps remain structurally sound, but the cloth has blinded from chemical scale, calcification, or body oils, or has torn from repeated backwash cycles.

Technical Specifications & Scope of Delivery

• Open bottom collar secured with band clamp above base shoulder | | Included Accessories | • 316 Stainless steel worm-gear retention clamp or nylon cable tie set

• Replacement base Buna-N/EPDM O-ring or high-density felt compression collar | | Excluded Components | Rigid slotted/perforated Schedule 80 PVC core cylinder, blind top cap, threaded/spud base hub |

Material Properties & Chemical Tolerances

• Chlorine & Saline Resistance: Virgin polypropylene fibers resist chemical degradation, rot, and hydrolysis under continuous exposure to elevated free chlorine, sodium hypochlorite shock dosing, and saline electrolytic pool water (2,500 to 5,000+ ppm NaCl).

• Acid Descaling Resilience: Withstands routine chemical descaling baths in dilute muriatic (hydrochloric) or citric acid to dissolve embedded calcium scale, iron staining, and organic oils without weakening structural seam threads.

• Pre-Coat Retention & Release: The balanced monofilament weave structure retains standard DE powder and perlite grades without bleed-through during initial pump startup, while facilitating clean cake release during backwashing or manual hose-down.

Physical Dimensions & Weight Estimates

• Individual Cover Net Weight: Approximately 0.35 to 0.55 lbs (0.16 to 0.25 kg).

• Single Boxed Cover Shipping Weight: Approximately 0.90 to 1.50 lbs (0.41 to 0.68 kg) in a compact carton.

• Master Carton / Tube Bank Lot (12 to 24 Covers): Approximately 5.5 to 11.0 lbs (2.5 to 5.0 kg).

• Full Vault Overhaul Pack (50 to 100 Covers): Approximately 20.0 to 38.0 lbs (9.1 to 17.2 kg).

Field Re-Covering & Tensioning Steps

1. Strip Spent Sock: Remove the tubular element from the manifold. Loosen the top and bottom band clamps, slide the calcified cover off the support core, and discard the spent base gasket/O-ring.

2. Core Wash-Down & Inspection: Pressure-wash the bare slotted/perforated cylinder to clear internal calcified DE and scale. Inspect the plastic core and end-caps for cracks, rough edges, or broken slots that could tear the new fabric.

3. Slide Replacement Sleeve: Slide the replacement tubular sock over the top blind cap, pulling it down smoothly along the 48" cylinder until the bottom hem reaches the base hub shoulder.

4. Bottom Hem Clamping: Position the lower edge of the sleeve directly above the base fitting shoulder. Fasten the 316 stainless steel worm-gear clamp firmly over the hem to ensure a tight hydraulic seal that prevents DE from bypassing into the discharge port.

5. Axial Tensioning & Top Closure: Pull the sleeve upward to eliminate wrinkles, sagging, or axial twisting along the tube body. Fold or tension the top hem over the blind end-cap and tighten the top band clamp or draw-cord tie securely around the top cap boss.

6. Mount Base Seal: Install the replacement Buna-N/EPDM O-ring or felt compression collar onto the base spud before threading or pressing the re-covered tubular element back into the Keene-Bowser tube-sheet receiver.