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Commercial Pool and Spa Supplies

4" FVS-XWB Single Arm Float Valve with Extra Weighted Ball - Inline

4" FVS-XWB Single Arm Float Valve with Extra Weighted Ball - Inline

4FVS-XMB

$2,354.00
$2,354.00
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Shipping calculated at checkout.

The 4" FVS-XWB Single Arm Float Valve with Extra Weighted Ball – Inline (also cataloged as 4FVSP-XWB-IL or 4FVS-XWB in commercial aquatic flow-control lines) is a heavy-duty mechanical water-level control valve engineered for pressurized or submerged inline piping inside commercial aquatic surge tanks, collector pits, and balance tanks. Unlike Open-Pipe (-OP) models that discharge freely at the end of a pipe stub, the Inline configuration features both an inlet and an outlet connection to remain continuously plumbed within a closed or submerged piping run. Equipped with an Extra Weighted Ball (-XWB), it provides amplified downward gravitational torque to ensure positive, reliable valve opening against upstream line pressure or mechanical seal friction as surge tank water levels drop.

Parameter Specification
Equipment / Part Reference 4" FVS-XWB Single Arm Float Valve with Extra Weighted Ball – Inline
Nominal Pipe Size 4.0 in (100 mm / DN100)
Connection Configuration Inline (Inlet x Outlet): Female IPS Slip Sockets (Schedule 40/80 PVC, 4.50" ID) or ANSI Class 150 Flanged ends for continuous inline piping integration
Actuation Mechanism Mechanical Single-Arm Lever Linkage with Extra-Weighted Ballast Float (requires no electricity or compressed air)
Valve Body & Housing Material Heavy-duty machined Schedule 80 PVC, CPVC, or reinforced FRP composite
Pivot Arm & Linkage Hardware Heavy-gauge 316 Marine-Grade Stainless Steel arm, machined clevis pivot, hinge pins, and locknuts (eliminates galvanic corrosion and chlorine stress-cracking)
Float Ball / Ballast Element Extra Weighted Ball (XWB): Heavy-wall seamless HDPE, Polypropylene, or 316 Stainless Steel spherical/cylindrical float (typically 10" to 12" diameter) internally ballasted / weighted for high opening torque
Internal Seat & Disc Seal Replaceable thick-wall EPDM or Neoprene elastomer disc / flapper or butterfly-style internal throttling element
Recommended Flow Capacity Approx. 180 to 380 US gpm (40.9 to 86.3 m³/h) depending on available gravity or low-pressure line head
Maximum Operating Pressure 25 to 50 psi (1.72 to 3.45 bar) — reinforced inline housing withstands downstream piping containment and higher static line heads than open-discharge models
Operating Temperature Range 32°F to 120°F (0°C to 49°C)
Level Adjustment Range Indexed pivot clevis and adjustable float rod pitch allow field calibration of operating water elevation (+/- 4 to 8 in)
Compliance / Standards NSF/ANSI Standard 50 compatible materials; meets Model Aquatic Health Code (MAHC) surge tank level control requirements

Hydraulic & Mechanical Operating Details

  • Function of the Extra Weighted Ball (XWB): In inline valve bodies where internal shaft seals, O-rings, or differential line pressures create higher breakaway friction than a free-falling open-pipe flapper, a standard hollow float may hang or open sluggishly when water levels drop. The internally ballasted Extra Weighted Ball adds deadweight leverage on the downward stroke to forcefully crack the valve open while retaining sufficient net buoyancy displacement to close drip-tight when submerged.

  • Inline Piping Integration: Installed directly in-series along submerged suction-equalizer lines, main-drain modulation headers, or enclosed gravity transfer pipes inside the surge tank, directing flow cleanly into downstream headers without aeration or splashing.

  • Nomenclature Breakdown: 4 = 4-inch nominal bore; FV = Float Valve; S = Single-Arm lever mechanism; XWB = Extra Weighted Ball float assembly; Inline = dual-ended (inlet/outlet) inline body.

  • Shipping Weight: Approx. 18 to 26 lbs (8.2 to 11.8 kg) complete with 4" inline valve body, 316 SS single pivot arm, adjustable linkage hardware, and extra-weighted ballast float.

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