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In-stock parts
Order by 2PM MST
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For permitted non-DOT applications. Do not use this assembly as a replacement on MC306 or DOT406 cargo tanks. Weld collar sold separately.
The Betts FVA9716BXB PAF450 16-inch manway assembly combines a clamp-ring manhole cover with a 10-inch reclosing pressure-relief valve and a pressure/vacuum normal vent. The relief cover also opens for inspection, allowing access through the smaller central hatch without removing the complete manhole assembly.
This configuration has zinc-plated steel for the manhole cover, strongback, and latch, aluminum relief-cover and vent components, and nitrile (Buna-N) seals. Select it by the existing manway size, tank application, and compatibility of the seals with the contents. It is the standard-latch assembly; a self-latching mechanism is an optional configuration.
The secondary safety catch provides an intermediate catch for the inspection cover. The included normal vent serves the tank's routine pressure/vacuum venting needs, while the larger valve provides reclosing pressure relief. Neither feature replaces checking the tank's required relief capacity and permitted equipment specification.
| Feature | Benefit |
|---|---|
| Central inspection hatch | Access the tank through the relief cover without removing the full clamp-ring assembly. |
| Secondary safety catch | Provides a second catch position when opening the inspection cover. |
| Reclosing relief valve | Returns toward its closed position after a pressure-relief event. |
| Replaceable seals and components | Allows worn parts to be serviced using compatible genuine Betts replacements. |
| Specification | Detail |
|---|---|
| Manufacturer part number | FVA9716BXB |
| Model and nominal manway size | PAF450; 16 inches |
| Relief valve size | 10 inches |
| Cover, strongback, and latch | Zinc-plated steel |
| Relief cover and normal vent | Aluminum |
| Seal selection | Nitrile (Buna-N) |
| Minimum relief set pressure | 3.0 psig |
| Rated air relief capacity | 375,000 SCFH at 5 psig |
| Rated water relief capacity | 1,434 gpm at 5 psig |
| Manhole and clamp-ring test pressure | 36 psig; this is a test value, not a tank operating-pressure rating |
| Component | Selection |
|---|---|
| Included assembly | Manhole cover with relief-valve mechanism, normal vent, seals, and clamp-ring hardware. |
| Weld collar | Excluded; select separately to match the tank shell material and manway dimensions. |
| Self-latch conversion | Optional 6807SL-KIT1; not included in this standard-latch model. |
| Additional inbreathing vent | The FVA configuration does not include the separate vent supplied with the FSA-prefix version. |
Have the installer inspect the existing collar and clamp-ring arrangement. A distorted, corroded, or damaged sealing surface can prevent proper seating. Use a collar that stays flat and round after welding, and verify that the gasket is compatible with the carried product.
| Check | Requirement |
|---|---|
| Tank specification | Confirm this non-DOT assembly is permitted for the application; it is not a replacement assembly for MC306 or DOT406 tanks. |
| Fit and seals | Confirm 16-inch nominal size, collar condition, seal compatibility, and required relief performance. |
| Installation | Follow Betts EB-01-08 for seating the clamp ring and final fastener torque; a visible gap must remain between ring ends. |
| Clamp integrity | Inspect to EB-08-25; remove from service any ring with damaged welds, distorted clips, or contacting ends. |
| Service safety | Safely relieve residual tank pressure and address fall, pinch, and cargo-related hazards before work. |
| California warning | Chromium (hexavalent compounds) exposure can cause cancer and reproductive harm. See P65Warnings.ca.gov. |
Need help confirming the correct assembly? Contact UnitedBuilt through online chat, email parts@unitedbuilt.com, or call 602-253-7750 with your tank specification, manway size, and existing assembly number.
| Model Number | PAF450 |
|---|---|
| Weight | 33.0 lb |