Gravity Flow Rack


High Density First In, First Out Management System
Gravity Flow Pallet Rack Systems are ideal for supplying pallet or carton loads of common SKUs in sorting and distribution operations. They also are a great option where high throughput is required or in a warehouse storage situation that calls for large volumes of each SKU.
Feeds pallets and cartons of product to processing, order picking and shipping.

Gravity flow pallet racks act like a conveyor within a rack structure. Pallets are deposited at the charge end and then flow down an incline to be picked at the opposite end. Systems can be 6 or more bays high and can run from a few to 15 positions deep. Using gravity to gently keep pallet loads staged for picking operations, flow racks are an economical first-in first-out storage rack solution.
Ridg-U-Rak conducts pallet flow tests using the client's actual pallet loads for a reliable, efficient and well-designed pallet rack solution. Our experienced engineering staff works directly with Ridg-U-Rak project managers to ensure that all specifications are met. Installation services are available and pallet rack projects are completed on time and on budget.
Columns Sizes: 3x2-4, 3x3 and 4x3-inch
Beam Sizes: 5-inch roll-formed
Standard Load: 3,000 lbs
Features & Benefits:
Applications:
Upright Frames
capacity charts
Frame Capacities
Vertical Beam |
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Spacing | UF-S31I | UF-S32I | UF-S33I | UF-R33I | UF-M33I | UF-Y33I | UF-H33I | UF-M43I | UF-H43I |
36" | 19,100 | 23,500 | 28,600 | 34,100 | 38,800 | 42,100 | 47,000 | 47,900 | 62,600 |
42" | 17,900 | 22,100 | 26,900 | 33,100 | 35,600 | 39,500 | 43,000 | 45,700 | 60,500 |
48" | 16,700 | 20,600 | 25,100 | 29,800 | 33,800 | 36,600 | 40,900 | 44,500 | 58,100 |
54" | 15,200 | 18,900 | 23,100 | 27,500 | 31,900 | 33,600 | 38,600 | 43,100 | 55,300 |
60" | 13,800 | 17,200 | 21,100 | 25,000 | 28,100 | 30,400 | 33,900 | 40,200 | 52,400 |
72" | 10,800 | 13,700 | 17,000 | 20,000 | 22,300 | 24,100 | 26,800 | 35,300 | 46,000 |
84" | 8,200 | 10,600 | 13,200 | 15,400 | 17,200 | 18,600 | 20,700 | 30,200 | 39,300 |
96" | 6,500 | 8,400 | 10,500 | 12,200 | 13,500 | 14,700 | 16,300 | 25,200 | 32,800 |
108" | 5,200 | 6,800 | 8,500 | 9,900 | 10,900 | 11,800 | 13,100 | 20,500 | 26,600 |
Consult with factory for vertical beam-to-beam spacings greater than 108"
• The Frame Capacity Chart gives allowable loads based on the specified "Unsupported Length" of the columns.
• Values shown are in full compliance with the current RMI Specifications.
• The loads on upright frames accumulate from top to bottom, therefore, the unsupported length and the column load below each beam level should be checked to determine the worst-case scenario.
• The capacities shown in this table are for static load conditions only.
• For other special conditions such as seismic or wind loadings, consult with Ridg-U-Rak sales.
Frame Capacities
Vertical Beam |
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Spacing | UF-S32C | UF-M32C | UF-H32C | UF-S33C | UF-R33C | UF-M33C | UF-Y33C | UF-H33C | UF-M43C | UF-H43C |
36" | 24,700 | 29,800 | 36,400 | 29,800 | 35,500 | 40,500 | 44,000 | 49,100 | 51,700 | 63,200 |
42" | 23,500 | 27,900 | 34,100 | 28,100 | 33,500 | 37,100 | 41,300 | 45,000 | 49,400 | 61,100 |
48" | 22,100 | 26,900 | 32,800 | 26,200 | 31,100 | 35,300 | 38,300 | 42,700 | 48,000 | 58,700 |
54" | 20,700 | 25,700 | 31,300 | 24,200 | 28,700 | 33,300 | 35,100 | 40,400 | 46,600 | 55,900 |
60" | 19,000 | 23,200 | 28,200 | 22,000 | 26,000 | 29,300 | 31,800 | 35,400 | 43,400 | 53,000 |
72" | 15,700 | 19,100 | 23,200 | 17,700 | 20,800 | 23,300 | 25,200 | 28,100 | 38,100 | 46,500 |
84" | 12,400 | 15,200 | 18,500 | 13,800 | 16,100 | 17,900 | 19,400 | 21,600 | 32,600 | 39,700 |
96" | 9,900 | 12,300 | 14,800 | 10,900 | 12,700 | 14,100 | 15,300 | 17,000 | 27,200 | 33,100 |
108" | 8,000 | 10,000 | 12,100 | 8,900 | 10,300 | 11,400 | 12,300 | 13,700 | 22,200 | 26,900 |
Consult with factory for vertical beam-to-beam spacings greater than 108"
• The Frame Capacity Chart gives allowable loads based on the specified "Unsupported Length" of the columns.
• Values shown are in full compliance with the current RMI Specifications.
• The loads on upright frames accumulate from top to bottom, therefore, the unsupported length and the column load below each beam level should be checked to determine the worst-case scenario.
• The capacities shown in this table are for static load conditions only.
• For other special conditions such as seismic or wind loadings, consult with Ridg-U-Rak sales.
Frame capacity chart - Slotted Connection
Vertical Beam Spacing | SSF-335 |
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36" | 34,200 |
48" | 33,300 |
60" | 30,000 |
72" | 24,000 |
84" | 18,400 |
96" | 14,200 |
108" | 11,300 |
Frame capacity chart - Bolted Connection
Vertical Beam Spacing | SBF-335 | SBF-341 | SBF-445 |
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36" | 34,200 | 40,300 | 51,600 |
48" | 33,300 | 39,200 | 50,600 |
60" | 30,000 | 35,000 | 50,000 |
72" | 24,000 | 27,600 | 44,500 |
84" | 18,400 | 21,000 | 38,600 |
96" | 14,200 | 16,100 | 32,600 |
108" | 11,300 | 12,800 | 26,800 |
Horizontal Beams
capacity charts
Beam Capacities

Beam Profile |
Beam Lengths | ||||||||||
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48" | 60" | 72" | 84" | 92" | 96" | 102" | 108" | 120" | 144" | 156" | |
250 S | 5,700 | 4,530 | 3,130 | 2,300 | 1,910 | 1,750 | 1,550 | 1,380 | 1,120 | 770 | 660 |
300 S | 7,500 | 5,980 | 4,820 | 3,530 | 2,940 | 2,690 | 2,380 | 2,120 | 1,720 | 1,190 | 1,010 |
355 S | 9,760 | 7,770 | 6,460 | 5,330 | 4,440 | 4,070 | 3,600 | 3,210 | 2,590 | 1,790 | 1,520 |
410 L | 10,810 | 8,620 | 7,150 | 6,110 | 5,570 | 5,200 | 4,600 | 4,100 | 3,310 | 2,290 | 1,940 |
410 S | 12,000 | 9,780 | 8,120 | 6,930 | 6,320 | 5,830 | 5,160 | 4,600 | 3,710 | 2,570 | 2,180 |
465 S | 12,000 | 11,970 | 9,940 | 8,490 | 7,740 | 7,410 | 6,960 | 6,320 | 5,110 | 3,530 | 3,000 |
500 S | 12,000 | 12,000 | 11,170 | 9,540 | 8,700 | 8,330 | 7,830 | 7,380 | 6,140 | 4,250 | 3,610 |
550 S | 18,000 | 18,000 | 18,000 | 11,150 | 10,160 | 9,720 | 9,140 | 8,620 | 7,740 | 5,420 | 4,610 |
600 S | 18,000 | 18,000 | 18,000 | 12,850 | 11,710 | 11,210 | 10,540 | 9,940 | 8,920 | 6,790 | 5,770 |
650 S | 18,000 | 18,000 | 18,000 | 14,660 | 13,360 | 12,790 | 12,020 | 11,340 | 10,180 | 8,360 | 7,110 |
650 R | 18,000 | 18,000 | 18,000 | 18,000 | 15,160 | 14,520 | 13,640 | 12,870 | 11,550 | 9,370 | 7,970 |
• Capacities are based on uniformly distributed loads per pair of beams.
• Capacities listed are for non-seismic conditions. For seismic conditions consult with Ridg-U-Rak sales or engineering.
Beam Capacities

Beam Profile |
Beam Lengths | ||||||||||
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48" | 60" | 72" | 84" | 92" | 96" | 102" | 108" | 120" | 144" | 156" | |
250 S | 5,700 | 4,530 | 3,130 | 2,300 | 1,910 | 1,750 | 1,550 | 1,380 | 1,120 | 770 | 660 |
300 S | 7,500 | 5,980 | 4,820 | 3,530 | 2,940 | 2,690 | 2,380 | 2,120 | 1,720 | 1,190 | 1,010 |
355 S | 9,760* | 7,770 | 6,460 | 5,330 | 4,440 | 4,070 | 3,600 | 3,210 | 2,590 | 1,790 | 1,520 |
410 L | 10,810* | 8,620 | 7,150 | 6,110 | 5,570 | 5,200 | 4,600 | 4,100 | 3,310 | 2,290 | 1,940 |
410 S | 12,270* | 9,780* | 8,120 | 6,930 | 6,320 | 5,830 | 5,160 | 4,600 | 3,710 | 2,570 | 2,180 |
465 S | 15,020* | 11,970* | 9,940* | 8,490 | 7,740 | 7,410 | 6,960 | 6,320 | 5,110 | 3,530 | 3,000 |
500 S | 16,890* | 13,460* | 11,170* | 9,540* | 8,700 | 8,330 | 7,830 | 7,380 | 6,140 | 4,250 | 3,610 |
550 S | 19,720* | 15,710* | 13,050* | 11,150* | 10,160* | 9,720* | 9,140* | 8,620 | 7,740 | 5,420 | 4,610 |
600 S | 22,500* | 18,120* | 15,050* | 12,850* | 11,710* | 11,210* | 10,540* | 9,940* | 8,920 | 6,790 | 5,770 |
650 S | 22,500* | 20,670* | 17,160* | 14,660* | 13,360* | 12,790* | 12,020* | 11,340* | 10,180* | 8,360 | 7,110 |
650 R | 22,500* | 22,500* | 19,480* | 16,640* | 15,160* | 14,520* | 13,640* | 12,870* | 11,550* | 9,370* | 7,970 |
• Capacities marked with * indicate that the column connection capacity may be limited based on the hook option and/or frame model (see table below).
• Capacities listed are for non-seismic conditions. For seismic conditions consult with Ridg-U-Rak sales or engineering.
• Capacities are based on uniformly distributed loads per pair of beams.
• Capacities listed are for a 2-pallet wide condition.
• All beams over 114" in length should utilize at least one flanged, tek-screwed or lock-in cross bar located at mid length.
Beam Capacities - Slotted Connection

Beam Length | ![]() |
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Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | |
48" | 10,880 | 11,160 | 12,290 | 12,290 | 18,510 | 18,910 | ||||
54" | 9,350 | 9,920 | 10,640 | 10,930 | 15,860 | 16,810 | ||||
72" | 6,280 | 7,210 | 7,330 | 7,930 | 10,550 | 12,610 | 18,810 | |||
84" | 4,970 | 5,300 | 5,830 | 5,830 | 8,060 | 10,810 | 14,840 | 18,960 | ||
92" | 4,140 | 4,420 | 4,860 | 4,860 | 6,650 | 9,870 | 12,330 | 17,310 | ||
96" | 3,800 | 4,060 | 4,460 | 4,460 | 6,080 | 9,320 | 11,280 | 16,590 | ||
102" | 3,360 | 3,600 | 3,950 | 3,950 | 5,350 | 8,260 | 9,940 | 15,620 | 14,130 | |
108" | 2,990 | 3,210 | 3,530 | 3,530 | 4,750 | 7,370 | 8,830 | 14,750 | 12,520 | |
120" | 2,420 | 2,600 | 2,860 | 2,860 | 3,820 | 5,970 | 7,100 | 12,880 | 10,030 | |
132" | 2,000 | 2,150 | 2,360 | 2,360 | 3,140 | 4,930 | 5,840 | 10,640 | 8,220 | 17,640 |
144" | 1,670 | 1,810 | 1,990 | 1,990 | 2,630 | 4,150 | 4,880 | 8,940 | 6,870 | 15,640 |
156" | 1,430 | 1,540 | 1,690 | 1,690 | 2,230 | 3,530 | 4,150 | 7,620 | 5,820 | 13,330 |
180" | 1,070 | 1,160 | 1,270 | 1,270 | 1,670 | 2,660 | 3,100 | 5,730 | 4,340 | 10,010 |
Note: Beams must be secured by beam locks against accidental upward forces. All capacities are per pair of beams based on uniformly distributed loads. Capacities are based on current RMI specifications.
Beam Capacities - Bolted Connection

Beam Length | ![]() |
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Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | Un-braced Cap/pr | Braced Cap/pr | |
48" | 10,880 | 11,160 | 12,290 | 12,290 | 18,510 | 18,910 | ||||
54" | 9,350 | 9,920 | 10,640 | 10,930 | 15,860 | 16,810 | ||||
72" | 6,280 | 7,210 | 7,330 | 7,930 | 10,550 | 12,610 | 18,810 | |||
84" | 4,970 | 5,300 | 5,830 | 5,830 | 8,060 | 10,810 | 14,840 | 18,960 | ||
92" | 4,140 | 4,420 | 4,860 | 4,860 | 6,650 | 9,870 | 12,330 | 17,310 | ||
96" | 3,800 | 4,060 | 4,460 | 4,460 | 6,080 | 9,320 | 11,280 | 16,590 | ||
102" | 3,360 | 3,600 | 3,950 | 3,950 | 5,350 | 8,260 | 9,940 | 15,620 | 14,130 | |
108" | 2,990 | 3,210 | 3,530 | 3,530 | 4,750 | 7,370 | 8,830 | 14,750 | 12,520 | |
120" | 2,420 | 2,600 | 2,860 | 2,860 | 3,820 | 5,970 | 7,100 | 12,880 | 10,030 | |
132" | 2,000 | 2,150 | 2,360 | 2,360 | 3,140 | 4,930 | 5,840 | 10,640 | 8,220 | 17,640 |
144" | 1,670 | 1,810 | 1,990 | 1,990 | 2,630 | 4,150 | 4,880 | 8,940 | 6,870 | 15,640 |
156" | 1,430 | 1,540 | 1,690 | 1,690 | 2,230 | 3,530 | 4,150 | 7,620 | 5,820 | 13,330 |
180" | 1,070 | 1,160 | 1,270 | 1,270 | 1,670 | 2,660 | 3,100 | 5,730 | 4,340 | 10,010 |
Note: All capacities are per pair of beams based on uniformly
distributed loads. Capacities are based on current
RMI specifications.
Options (Frame & Beam)
Must be specified at the time of manufacturing
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Flow System - Virtual Showroom
Gravity Flow are high density "First In, First Out" rack systems. Rollers and brakes are commonly used to feed pallets down an incline to a staging or picking operation. Systems are multiple levels high, and multiple positions deep. Flow rack systems provide an effective storage option for applications involving a low number of SKUs and high inventory turns, and are useful when storing time sensitive products.
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Ridg-U-Rak installed a highly efficient, organized storage rack system that keeps our production floor moving at top speed.