1 1

Commercial Pool and Spa Supplies

Mermade 39" x 50" Bottom Outlet (Keene-Bowser Replacement), Cover Only

Mermade 39" x 50" Bottom Outlet (Keene-Bowser Replacement), Cover Only

DE-BO3950CO

$415.00
$415.00
Sale Sold out
Shipping calculated at checkout.

The Mer-Made 39" × 50" Bottom Outlet (Keene-Bowser Replacement) — Cover Only (cataloged under Part # 775-COVER / VFC-3950-BO) is the replacement woven fabric filter jacket envelope designed to re-cover existing bare leaf frames in large-format commercial and municipal vacuum DE vaults retrofitting legacy Keene-Bowser (Bowser-Briggs / Keene Corporation) filtration systems.

This configuration supplies only the tailored synthetic filtration envelope, factory-reinforced bottom discharge cutout collar, top closure system, and replacement compression felt gasket/collar. It is specified when the internal drainage matrix core and outer rigid PVC/CPVC borders remain structurally sound, but the existing cloth has blinded from chemical scale, calcification, or body oils, or has torn from repeated backwash cycles.

Technical Specifications & Scope of Delivery

Specification Parameter / Detail
Model / Application Mer-Made Replacement Septum Jacket (Keene-Bowser Retrofit)
Configuration Cover Only (Fabric envelope + gasket; excludes internal grid core and frame)
Nominal Dimensions 39" Wide × 50" High (approx. 991 mm × 1270 mm flat envelope)
Active Surface Area 27.0 sq. ft. nominal pre-coat area (both faces combined)
Effluent Port Cutout Pre-cut, reinforced bottom outlet collar aligned for Keene-Bowser 1-1/4" or 1-1/2" IPS spud profiles
Outlet Location Bottom rail cutout (centered or offset to match specific vault header spacing)
Fabric Composition High-tenacity, custom-woven monofilament or multifilament polypropylene
Filtration Porosity Calibrated nominal 20 to 30 micron pore rating for diatomaceous earth pre-coat retention
Closure Mechanism Heavy-duty commercial Velcro hook-and-loop flap across the top rail (or heavy lace-up seam)
Included Accessories High-density replacement felt compression collar (Part # FELTCOLLAR)
Excluded Components Rigid ABS/PVC perimeter frame, internal open-matrix drainage grid core

Material Properties & Operating Limits

  • Chemical & Electrolyte Resistance: Virgin woven polypropylene fibers resist degradation, rot, and hydrolysis under prolonged exposure to high free chlorine levels, sodium hypochlorite shock treatments, and saline pool environments (2,500 to 5,000+ ppm NaCl).

  • Acid Wash Survivability: Tolerates routine chemical descaling baths using dilute muriatic (hydrochloric) or citric acid solutions to dissolve embedded calcium carbonate, iron scale, and body grease without breaking down seam stitching.

  • Cake Retention & Release: The balanced monofilament weave structure retains standard DE powder and perlite grades without bleed-through during initial pump startup, while providing low-friction cake release during manual hose-down or backwash cycles.

Physical Dimensions & Weight Estimates

  • Individual Cover Net Weight: Approximately 1.35 to 1.85 lbs (0.61 to 0.84 kg).

  • Single Boxed Cover Shipping Weight: Approximately 2.75 to 4.0 lbs (1.25 to 1.81 kg) in a compact corrugated box.

  • Master Carton / Multi-Pack (6 to 12 Covers): Approximately 13 to 24 lbs (5.9 to 10.9 kg).

  • Full Vault Overhaul Pack (20 to 30 Covers): Approximately 32 to 52 lbs (14.5 to 23.6 kg).

Field Re-Covering & Tensioning Steps

  1. Strip Old Jacket: Remove the spent leaf from the pit. Open the top closure seam, pull the degraded cover off the core, and discard the compressed felt collar.

  2. Core Wash-Down & Inspection: Pressure-wash the bare polypropylene drainage grid to clear hardened DE residue. Inspect the outer PVC frame for hairline cracks, warpage, or sharp burrs that could puncture the new fabric.

  3. Sleeving the Frame: Slide the replacement cover down over the 50" height of the frame, guiding the bottom reinforced cutout over the protruding lower discharge spud.

  4. Seating the Cutout: Stretch the reinforced collar cutout snugly around the base of the discharge hub until seated flush against the molded locating shoulder without bunching.

  5. Tensioning & Sealing: Pull the fabric upward evenly from both sides to ensure tautness across the 39" × 50" face (loose fabric leads to uneven pre-coat cakes and cracking under vacuum). Firmly press the top Velcro flap closed across the upper frame rail.

  6. Mount Felt Collar: Slide a new felt compression collar onto the bottom outlet spud against the locating shoulder before lowering the re-covered leaf back into the Keene-Bowser floor manifold receiver.

View full details