Branch Fitting Shapes/types

Branch connection fittings, commonly referred to as O'lets 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 the items listed below (in materials listed as “standard materials”) for a same-day or next-day delivery. Large quantites, 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

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 Weldolets (XH and STD), Threadolets (3000#), and Sockolets (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

O-Let Styles Available

There are three common styles of O-lets: weldolet, threadolet, and sockolet. They are given their name by the manner in which they connect to the branch pipe. The weldolet has a buttweld connection, the threadolet has a threaded connection, and the sockolet has a socket weld connection. In addition to these three common styles, there are also elbolets, nippolets, laterolets, and we can offer these as well.

Common Manufacturers




	Approved Branch Fittings Manufacturers Country




	Bonney Forge Canada/Italy


	Capitol Camco USA


	Phoenix Forge USA


	IMF USA