UNSPSC 31181705: Seal backup ring

A type of ring having backup holding and sealing action. Back-up rings are washer-like devices that are used to prevent a seal from extruding through any gaps while under pressure. Back-up rings are not seals themselves, but are usually used in conjunction with O-rings in high-pressure applications and are installed in the downstream side of the gland.

UNSPSC 31181705 Seal backup ring is a Commodity code that covers elastomeric and synthetic sealing components used in infrastructure, equipment, and vehicle maintenance — specifically backup rings, compression seals, and related sealing materials that support joint integrity and fluid containment in bridges, roads, fleet equipment, and municipal infrastructure systems. State and local governments procure these items through cooperative purchasing vehicles, single-jurisdiction RFQs, and master supply agreements when equipping maintenance departments and public works operations. The issuing bodies span state departments of transportation, county purchasing offices managing fleet operations, city public works departments, school district transportation operations, and cooperative purchasing authorities serving multiple jurisdictions.

The Maine Department of Transportation, through the State of Maine Department of Administrative and Financial Services, posted RFQ 17A260427-275 on May 18, 2026 (due June 1, 2026) for bridge joint seals and related materials across multiple compression seal sizes, silicone-coated foam seals, gland seals, lubricants, sealants, and backer rod for delivery to nine MaineDOT locations across five regions, with an initial one-year contract period from June 15, 2026 through June 30, 2027 and four optional one-year extensions. Recent activity centers in Maine and Florida, with secondary procurement reaching Georgia, Minnesota, and Texas jurisdictions. The source also includes unrelated opportunities — a Williamson County (Texas) departmental relocation notice, a Sourcewell law enforcement equipment RFP, a Brevard County fleet inventory management IFB, an Atlanta heavy-duty trailer IFB, and a Sarasota County Schools automotive parts bid — none of which align with the seal backup ring code's scope. The code shows meaningful recent activity only in Maine's transportation maintenance context; the broader issuing-body and geographic data in the source does not support characterization of state and local seal backup ring procurement beyond that single representative opportunity.