Olets

Branch connection fittings, commonly referred to as allow a smaller "branch" pipe to be extended from a larger (or same sized) pipe run. Branch fittings are preferred whenever a non-reinforced miter-branch is satisfactory to withstand the internal pressure requirements.

Inventory

First Distributors can typically provide for a same-day or next-day delivery.

Large quantities, custom sizes, and special alloys (Alloy 20, Monel, Hastelloy, Inconel, Titanium, etc) may be subject to a longer lead time for delivery.




	Size Range: 1/4" to 36" Run Diameter, 1/4" to 2” Branch Diameter


	O-Let Style: Weldolet, Threadolet, Sockolet, lateralolet, nippolet, elbolet


	Standard Materials: A105, 304 SS, 316 SS


	Exotic Alloys: A20, C276, Duplex 2205, Duplex 2507, Monel, Inconel 600, Inconel 625, Incoloy 800, Incoloy 825

Weldolets

A weldolet is a type of branch connection fitting designed to provide a reinforced outlet from a run pipe. It is contoured to match the curvature of the header pipe and is welded directly to the pipe, creating a strong, integral connection.

Key Benefits of Weldolets:

Reinforced branch connection (stronger than stub-in)
Smooth flow transition
Reduced stress concentration
Ideal for high-pressure and high-temperature service

Common Weld-o-let Applications

Gas pipelines
Petrochemical plants
Power generation
High-pressure piping systems

Other Types of Branch Fittings (Olets)

In addition to weldolets, we supply a full range of branch connection fittings:

Sockolets

Socket weld connection
Ideal for smaller pipe sizes
Common in moderate pressure systems

Threadolets

Threaded outlet connection
Used in low-pressure or non-critical systems
No welding required

Latrolets

Designed for 45-degree lateral connections
Butt weld outlet

Elbolets

Used to create branch connections from elbows
Maintains system integrity at directional changes

Nipolets

Combination fitting (olet + nipple)
Common for valve take-offs and drains

Weldolet vs Other Branch Fittings




	Fitting Type Connection Best Use Case




	Weldolet Butt weld High pressure / critical service


	Sockolet Socket weld Smaller branch connections


	Threadolet Threaded Low-pressure systems


	Latrolet Butt weld 45° branch connections


	Elbolet Butt weld Connections off elbows

Fitting Type	Connection	Best Use Case
Weldolet	Butt weld	High pressure / critical service
Sockolet	Socket weld	Smaller branch connections
Threadolet	Threaded	Low-pressure systems
Latrolet	Butt weld	45° branch connections
Elbolet	Butt weld	Connections off elbows

A Guide To Branch And Run Size

The dimensions for a branch fitting are a common source of confusion. When specifying the dimensions for an o-let, the first dimension will indicate the diameter for the branch, and the second dimension will be the diameter of the run. As the image shows, the main pipe onto which the branch connection is welded is usually called the run (or header), and the pipe to which the branch connection provides extends is referred to as the branch (or outlet) size.

However, as can be seen in this image, the curvature beneath the O-let provides a "saddle" that is suitable for mounting on a range of "run" sizes. The chart below indicates the run size ranges, by outlet diameter, for Bonney Forge (XH and STD),(3000#), and (3000#). This chart also illustrates the importance of specifying the run diameter for the o-let application when ordering o-lets.

Branch Outlet Sizes




	1/8 ¼ 3/8 1/2 ¾ 1 1-1/4 1-1/2 2 2-1/2 3 3-1/2 4 5 6


	3/8 3/8 1/2 1/2 ¾ 1 1-1/4 1-1/2 1 2-1/2 3 3-1/2 4 5 6


	1/2 ½ 1-3/4 3/4 1 1-1/4 1-1/2 2 2-1/2 3 3-1/2 4 5 6 8


	1-3/4 1-3/4 2-1/2-1-1/4 1 1-1/2-1-1/4 1-1/2 2 2-1/2 3 3-1/2 4 5 6 8 10


	2-1/2-1-1/4 2-1/2-1-1/4 

36-3 1-1/2-1-1/4 2-1/2-2 2 2-1/2 3 4-3-1/2 4 5 6 8 10 14-12


	36-3 36-3 flat 2-1/2-2 5-3 2-1/2 3-1/2-3 4-3-1/2 5 5 6 8 10 10 16


	flat flat 8-3 12-6 3-1/2-3 5-4 6-5 6 6 8 10 14-12 14 18


	 36-10 36-10 5-4 8-6 12-8 10-8 8 10 14-12 20-16 18-16 22-20


	 flat flat 10-6 18-10 24-14 18-12 12-10 14-12 20-16 22 22-20 28-24


	 36-12 36-20 36-26 36-20 18-14 20-16 36-24 36-24 28-24 36-30


	 Flat Flat Flat Flat 36-20 36-24 Flat Flat 36-30 Flat

Common Manufacturers




	Approved Branch Fittings Manufacturers Country




	Bonney Forge Canada/Italy


	Capitol Camco USA


	Phoenix Forge USA


	IMF USA