BSPP Reducing Adapter, Bonded Seal

The BSPP reducing adapter with bonded seal joins two BSPP (ISO 228-1 parallel) connections of different sizes. Because parallel threads do not seal, a bonded seal, consisting of a metal ring with an elastomer lip vulcanized to its inner face, is used on the port side. The seal is compressed between the face of the adapter and the port face to provide sealing.

Because it is easier to remove and refit than a tapered thread, it is preferred on ports that are opened frequently during maintenance: pump and filter connections on hydraulic units, actuator lines on paper and board machines, ship deck machinery, and points subject to periodic maintenance in rolling mills.

• The bonded seal is selected by thread size; the fluid and temperature compatibility of the seal material (NBR, FKM, etc.) should be checked.
• The port face must be flat, clean and free of scratches; the seal will not hold on a damaged face.
• The opposite end may have a 60° cone seat or a seal; the type of the mating part should be stated on the order.

Installation note: Replacing the bonded seal every time the connection is taken apart is recommended; a crushed seal cannot be relied on to seal when reused.