What Is an Angle Valve?

Quick Answer

An angle valve is a globe valve variant where the inlet and outlet ports are at 90 degrees to each other. The flow enters horizontally and exits vertically (or vice versa), eliminating the need for a separate elbow. Angle valves produce lower pressure drop than standard globe valves because the flow changes direction only once instead of following an S-shaped path.

Key Specifications

Feature	Details
Function	Throttling and on/off with 90-degree flow change
Flow path	Single 90-degree turn (inlet to outlet)
Design basis	Globe valve body with angled ports
Pressure drop	Lower than standard globe valve (one turn vs two)
Standards	API 623, BS 1873 (cast), API 602, BS 5352 (forged)
Pressure classes	Class 150-2500 per ASME B16.34
Sizes	1/2” to 16”
Body materials	A216 WCB, A217 WC6/WC9, A351 CF8M
Trim	Standard API 600 trim numbers
End connections	Flanged, butt-weld, socket weld, threaded

How an Angle Valve Works

The stem and disc operate identically to a standard globe valve. The difference is geometry. In a standard globe valve, the flow enters the body, turns upward to pass the disc and seat, then turns again to exit through the opposite side; an S-shaped path with two direction changes.

In an angle valve, the flow enters through one port, passes the disc and seat, and exits through the perpendicular port. One direction change instead of two. This reduces turbulence, lowers the pressure drop coefficient, and decreases erosion on the body and trim.

Angle Valve vs Standard Globe Valve

Parameter	Angle Valve	Standard Globe Valve
Flow path	Single 90-degree turn	S-shaped (two turns)
Pressure drop (Cv)	Higher Cv (less restriction)	Lower Cv (more restriction)
Piping layout	Replaces globe valve + elbow	Requires straight run
Erosion resistance	Better (smoother flow path)	Moderate (flow impingement on body)
Throttling	Excellent	Excellent
Cost	Similar to globe valve	Similar
Weight	Lighter (eliminates one elbow)	Standard
Installation	Horizontal-to-vertical (or reverse)	In-line (horizontal or vertical)

Typical Applications

High-pressure letdown: reducing pressure from a high-pressure header to a lower-pressure system. The single-turn flow path minimizes cavitation and erosion compared to a standard globe valve in the same service.

Boiler blowdown: discharging boiler water from the bottom of the drum (horizontal) to a blowdown tank below (vertical). The angle body naturally accommodates the direction change.

Riser and drainpoint isolation: anywhere piping changes from horizontal to vertical, an angle valve replaces a globe valve and an elbow, saving weight, space, and a potential leak point at the elbow joint.

Cryogenic service: angle cryogenic valves are common in LNG plants where the reduced number of welds and fittings minimizes potential leak paths at extreme low temperatures.

Selection Criteria

Use an angle valve when the piping naturally requires a 90-degree direction change at the valve location. If the piping runs straight through, a standard globe valve or Y-globe valve is more appropriate. Angle valves follow the same face-to-face dimensions and pressure-temperature ratings as standard globe valves.

Pro Tip

Angle valves are particularly effective for slurry or erosive services where the globe valve S-path would cause severe impingement erosion. The single-turn flow path distributes the velocity change over a larger area, extending trim life.

Read the full guide to valve types