ASME B16.10 / Face-to-Face and End-to-End Dimensions
B16.10 is the table that makes a valve a drop-in replacement. It fixes how long the valve is, by type, size and class.
ASME B16.10 / Face-to-Face and End-to-End Dimensions
The distance between the faces of a valve is not a manufacturer's preference, it is a published dimension. ASME B16.10 sets face-to-face and end-to-end lengths for gate, globe, check, ball, butterfly and plug valves by size and class.
The reason it matters commercially is replacement. A piping run is fabricated around a stated dimension, so a valve that is 30 mm longer than the standard for its size and class will not go back into the spool it came out of.
Why the dimension varies by class
Higher classes need heavier bodies to hold the pressure, and a heavier body takes more room. B16.10 therefore publishes separate dimensions for the same nominal size at different classes, and for short-pattern and long-pattern variants where both exist.
It also distinguishes by valve type. A gate valve and a globe valve of the same size and class do not share a face-to-face dimension, because the flow path through the body is different.
Butterfly valves are treated separately
Butterfly valves are wafer or lug designs and their dimension set comes from API 609 rather than from the B16.10 table. That is worth remembering when a spool is being fabricated around a butterfly valve: the two documents are separate and a substitution between patterns changes the length.
For a butterfly valve, the face-to-face dimension and the flange bolt pattern have to match together. A valve with the right length and the wrong lug pattern will not bolt up.
How we use it
Face-to-face and end-to-end dimensions on our valves are checked against the standard named in the order, dimension by dimension, as part of the dimensional record that travels with the shipment.
Where a project specifies a non-standard length, we build to the drawing and state it on the datasheet, because the piping has usually been fabricated to the project drawing rather than to the generic table.
From the works and the projects
Questions this page answers
Butterfly valve face-to-face dimensions come from API 609. B16.10 covers the flanged and weld-end valve types such as gate, globe, check, ball and plug.
Most often because the sizes are the same but the class or the pattern is different, and the standard dimension changes with both. Check the dimension against the standard for the actual type, size and class.
Yes. Where the project drawing specifies a length outside the standard table, we build to the drawing and state the dimension on the datasheet.