Olets are integrally reinforced, forged branch outlet fittings made to MSS SP-97. Welded onto a hole in the run pipe, they provide a branch connection that is reinforced by the olet itself, without the cost and pressure drop of a full tee. They are used wherever a small branch, instrument connection, drain or vent leaves a larger pipe.
Raaj Fittings manufactures weldolets, sockolets and threadolets at our two plants in India, in carbon, low-temperature, alloy and stainless steel, duplex and nickel alloys.
| Olet | Branch connection | Typical use |
|---|---|---|
| Weldolet | Butt weld, bevelled to match the branch pipe schedule | Branches of 2" and larger, full-strength branch connections |
| Sockolet | Socket weld, Class 3000 or 6000 | Small-bore branches, instruments, drains and vents |
| Threadolet | Threaded (NPT), Class 3000 or 6000 | Instrument and gauge connections, drains and vents |
An olet is specified by the run pipe size (the olet base is contoured to fit it), the branch size and the branch schedule or class. For example: "Weldolet, 8" run × 2" branch, SCH 80, ASTM A105". Olets cover ranges of run sizes, and the base contour must match the run pipe for a good fit-up weld.
For equal or near-equal branches, a tee is normally used.
Olets are forged in ASTM A105 and A350 LF2, alloy steel A182 F11 / F22 / F91, stainless steel A182 F304L / F316L, duplex F51 / F53 and nickel alloys, matched to the run pipe material.
Every olet is made from PMI-verified material, dimensionally inspected against the ordered standard and marked with material, size, rating and heat number. Orders are supplied with EN 10204 3.1 certificates; EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request.
A weldolet has a butt-weld branch end for branches of about 2" and larger; a sockolet has a socket weld branch end for small-bore branches. Both are welded to the run pipe the same way.
By the run pipe size, the branch size, the branch schedule or class, and the material, for example "Weldolet 8" × 2" SCH 80 ASTM A105".
For small branches on larger pipes, olets are cheaper and lighter than tees and are integrally reinforced, so no reinforcing pad is needed.
MSS SP-97 covers integrally reinforced forged branch outlet fittings with socket welding, threaded and buttwelding ends.