Fittings, Flanges & Connections
Types of fittings, flange ratings, gasket selection, bolting procedures, and branch connections.
- Identify common pipe fittings and their applications
- Explain flange types, pressure-temperature ratings, and facing styles
- Select proper gaskets based on service conditions
- Describe flange bolt tightening sequences and torque procedures
- Identify branch connection types including weldolets and sockolets
Lesson 1
Pipe Fittings - Elbows, Tees, Reducers & Olets
Pipe Fitting Types
Pipe fittings change direction, branch, reduce, or join pipe runs. Every pipefitter must know the standard fittings, their dimensions, and proper applications. Fittings are available in butt-weld, socket-weld, threaded, and flanged configurations.
Elbows
Long radius (LR) elbows have a centerline radius of 1.5 times the pipe diameter. They are the standard choice because they create less pressure drop and turbulence. Short radius (SR) elbows have a centerline radius equal to the pipe diameter and are used where space is limited, but they create more pressure drop.
Tees and Reducers
A tee creates a 90-degree branch from the main pipe run. Equal tees have the same size on all three outlets. Reducing tees have a smaller branch outlet. Concentric reducers maintain a common centerline and are used on vertical runs. Eccentric reducers have an offset centerline and are used on horizontal runs to maintain a flat bottom (BOP - bottom of pipe) to prevent air pockets in liquid lines.
Exam Tip - Eccentric Reducers
On horizontal liquid lines, install eccentric reducers flat on bottom (FOB) to prevent air pockets. On horizontal steam lines, install them flat on top (FOT) to prevent condensate pooling.
Long radius elbows (1.5D) are standard; short radius (1.0D) for tight spaces. Eccentric reducers go flat on bottom for liquid lines and flat on top for steam lines. Concentric reducers are used on vertical runs.