Standard o-ring catalogues run out eventually. Large tank lids, manways, filter housings and custom equipment often need a ring bigger than anything moulded, or a size nobody standardised.
How a spliced ring is made
A length of extruded cord is cut to the required circumference and the ends are joined. Done properly, the joint is vulcanized — chemically bonded under heat and pressure so the join is continuous material rather than glue.
Custom size spliced and vulcanized o-rings are available in EPDM 70 durometer among other options.
Where splicing works well
- Static seals — tank lids, access covers, manways, housings. The joint is not being worked.
- Large diameters where moulding is impractical or the tooling does not exist.
- Non-standard sizes on custom or obsolete equipment.
- Low to moderate pressure static applications.
Where it does not
- Dynamic service. Anywhere the ring slides or rotates, the joint is a weak point.
- High pressure. The joint will not match moulded strength.
- Small diameters — moulded rings exist, cost less and perform better.
On-site splice kits
Splice kits let you make a ring from cord stock in the field, which is genuinely useful for emergency repairs on large equipment. Be realistic about the limits: a field splice is a temporary fix, not a permanent seal, and should be replaced with a properly vulcanized or moulded ring when one can be obtained.
Ordering
For a spliced ring we need the inside diameter and cross-section, the material and the durometer. If you are working from an old ring that has stretched or taken a set, measure the groove rather than the ring — a deformed seal will give you the wrong number.
Not sure? Send us the equipment details and we will work it out with you.
Before you reassemble
Seat every o-ring with a thin film of food-grade silicone. Dry rings pinch and take a set. Aqua Flex Food Grade Silicone Lubricant is what ships in our kits.
O-rings only. Never lubricate the polished faces of a mechanical shaft seal.
Beaver Island Parts Company is not affiliated with, endorsed by, or sponsored by any equipment manufacturer named on this page. All brand names, model numbers and part numbers are the property of their respective owners and are used solely to identify the equipment our replacement parts fit.