821 PRRS Roller Top Chain
821 PRRS carries products on rows of POM rollers above a straight-running chain. Three plate widths provide different carrying spans for cartons and packaged products.
- Route
- Straight running
- Plate Widths
- 190.5–304.8 mm
- Plate and Rollers
- POM
Use the Roller Span to Check Base Support
The roller contact width is narrower than the full plate width.
Matching Sprocket
For 821-series chains. Confirm the tooth count and shaft opening.
Matching Sprocket
For 821-series chains. Confirm the tooth count and shaft opening.
Separate the Carrying Width from the Contact Width
The rollers provide moving contact beneath the product. During accumulation they can turn under a restrained pack while the chain continues to travel. The product base must bridge the roller pattern to remain stable.
Plate width establishes the overall span of the link, while roller width describes the narrower contact zone. Keep these dimensions separate when sizing a lane or comparing a replacement with an existing roller-top chain.
Specifications
Plate and rollers are POM; pins are stainless steel.
| Chain Type | Plate Width (mm) | Roller Width (mm) | Minimum Reverse Radius (mm) |
|---|---|---|---|
| 821-PRRss-k750 | Plate Width (mm): 190.5 | Roller Width (mm): 174.5 | Minimum Reverse Radius (mm): 255 |
| 821-PRRss-k1000 | Plate Width (mm): 254 | Roller Width (mm): 238 | Minimum Reverse Radius (mm): 255 |
| 821-PRRss-k1200 | Plate Width (mm): 304.8 | Roller Width (mm): 288.8 | Minimum Reverse Radius (mm): 255 |
The plate widths correspond to 7.5, 10 and 12 inches. The 255 mm reverse radius is approximately 10.04 inches.
Review the Straight Track and Return
Check roller contact under the smallest pack, including seams or recessed areas in its base. Compare the chain support and drive geometry with the existing installation.
Allow for the specified reverse radius on the return path. The product-transfer gap requires a separate check against base length and roller-top height.
Accumulating Packs Before Release
Cartons or wrapped packs can wait against a downstream stop while the rollers turn beneath them. Guide spacing must keep the queue aligned without trapping a pack against the side rail.
When the stop releases, the product moves from a waiting state back into transport. Check the pack's base rigidity and the handoff to the next conveyor so it stays supported across the roller rows.
Request an 821 PRRS Width
Send the chain type, required length and quantity with the pack-base dimensions. Include the stop arrangement and return-path drawing for CSTRANS to review the roller span and fit.