Pallet flow rack
Also called: gravity flow rack, pallet flow racking, FIFO rack
A pallet flow rack is gravity racking where pallets ride on slightly inclined roller lanes from the loading aisle to the picking aisle, giving first in, first out rotation. The pallet's bottom deck rides directly on the rollers.
In depth: Pallets for automation: conveyors, AS/RS and robotic palletizers
Pallet flow racks suit high-volume product that must rotate first in, first out, such as food with date codes. Speed controllers and brakes on the lanes keep pallets from running away.
What it needs from the pallet
The bottom deck is the running surface, so the pallet behaves more like it does on a conveyor than on rack beams.
| Requirement | Why |
|---|---|
| Bottom members that span several rollers at once | Boards that drop between rollers stall or tip |
| Orientation agreed with the rack maker | Board direction relative to the rollers decides whether the pallet runs smoothly |
| No loose boards, protruding nails or missing boards | They jam lanes |
| Consistent quality and dimensions | Mixed pallets run at different speeds |
| Stiffness | Sagging bottoms drag on rollers |
The flow rack maker's pallet specification is authoritative, and many specify the pallet type, direction of travel, and minimum condition.
Why it matters
Flow racks are one of the places where recycled pallets with damaged bottom boards cause the most trouble. Some operations use a dedicated pallet type or grade for flow lanes.
On a spec sheet or RFQ
State "pallet flow rack", the direction of travel relative to the pallet's length, roller diameter and pitch if known, and the lane depth. Add any grade or condition rule.
Common confusions
A flow rack is not the same as push-back: flow racks load at one end and unload at the other, and pallets roll on the rollers themselves rather than on carts.
Related
- GlossaryWhat is pallet racking?Pallet racking is a steel storage structure of upright frames and horizontal beams that holds loaded pallets in levels above the floor. The pallet usually spans the gap between two beams, so its racking load rating, not its floor rating, governs.
- GlossaryPush-back rackA push-back rack stores pallets several deep on nested wheeled carts that roll on slightly inclined rails. Loading a new pallet pushes the others back, and removing the front pallet lets the rest roll forward, so stock is last in, first out.
- GlossaryConveyorA pallet conveyor moves loaded pallets on driven rollers or chains instead of a forklift. The pallet's bottom deck is the running surface, so the orientation of bottom boards, flatness, deflection and condition decide whether it runs reliably.
- GuidesPallets for automation: conveyors, AS/RS and robotic palletizersAutomated systems need consistent, flat, stiff pallets. Bottom boards must cross the conveyor supports (perpendicular to rollers, across chain strands), gaps must not snag, flatness is often held to 1/4 in or better, and AS/RS racks commonly limit sag to 0.5 in. Perimeter-base block and plastic pallets run either way.
- GlossaryBottom deck (pallet)The bottom deck is the lower layer of deckboards (or a perimeter, runner or panel base) on a double-face pallet. It spreads the load onto the floor, rack or conveyor and stabilizes the stringers or blocks.
More in Handling and storage
- GlossaryAutomated storageAutomated storage, often called AS/RS (automated storage and retrieval system), stores and retrieves pallets with stacker cranes, shuttles and conveyors instead of forklift drivers. It needs pallets with tight dimensional tolerances, low deflection (often 0.5 in, 13 mm, or less) and sound bottom decks.
- GlossaryBlock stackingBlock stacking is storing unit loads directly on top of one another on the warehouse floor, in rows and columns, with no racking. The bottom pallet and the packaging carry the whole stack, so static load and box compression strength limit the height.
- GlossaryDrive-in rackA drive-in rack is high-density racking where the forklift drives into a lane and places pallets many deep on continuous rails along each side. The pallet is supported only along two edges, so its capacity across the unsupported direction governs.
- GlossaryEdge protectorAn edge protector, or corner board, is an L-shaped strip of laminated paperboard, plastic or other material placed on the vertical or top edges of a unit load. It spreads strapping and stretch wrap pressure, protects case corners, and can add vertical stacking strength.
- GlossaryFork tinesFork tines are the two steel arms on a forklift or pallet jack that slide into a pallet's openings to lift it. Their width, thickness, length and spacing set the minimum size of the pallet's openings and affect its dynamic load rating.
- GlossaryPallet dispenserA pallet dispenser is a machine that holds a stack of empty pallets and releases them one at a time, usually onto a conveyor feeding a palletizer. It needs pallets with consistent dimensions, flat decks and sound bottom boards.
Last reviewed 2026-09-24. 266 words.