Double threaded nipple, reducing, Octagonal, R 2 1/2, R 2, AF 78 - Riegler 125685

Double threaded nipple, reducing, Octagonal, R 2 1/2, R 2, AF 78, Working pressure max. 20 bar, Stainless steel 1.4408

Technical data

Standards and origin

• Standard thread: ISO 7-1
• Customs tariff number: 73072910
• Country of origin: DE

About Double nipples

A double threaded nipple joins two female ports and bridges the size step when fitting and connection do not match. Both ends carry a male thread, either in the same size or reduced. Working pressure runs from 20 to 60 bar depending on the version.

What matters when choosing

• Thread 1 and thread 2 decide whether the nipple extends or reduces. Both sides are covered from M5 and G 1/8 up to G 1 1/4, the second side additionally up to R 2.
• The thread form determines how the joint seals. Parallel G threads to DIN EN ISO 228-1 need a separate seal, tapered R threads to ISO 7-1 seal in the thread itself.
• Brass CW614N is the default material. Electroplated nickel-plated brass CW614N suits visible installations and mild humidity, stainless steel 1.4571, 1.4408 and 1.4404 aggressive media.
• Working pressure between 20 and 60 bar depends on material and size. For large threads from G 1 upwards, check the value per article rather than assuming the top figure of the group.
• Maximum operating temperature sits between 150 °C and 200 °C. Where steam or hot oil is carried, that is the deciding criterion alongside pressure.

Typical applications

• Joining two female-threaded fittings in a pipe run without an extra socket
• Stepping down from a larger manifold port to a smaller connecting line
• Mounting gauges, shut-off valves and filters on air preparation units
• Extending a short connection spigot so a wrench can be applied
• Building manifolds for water, oil and neutral gases in workshop and plant construction

The NonPlusUltra versions are made from stainless steel 1.4404 and sealed with FDA-compliant FPM, released for compressed air, neutral gases and liquids, oil and grease. The value line series is also part of the group, which holds 292 articles in total.