This video shows how I make a compact 2" bore air cannon with a coaxial piston valve. To understand how these valves work examine the third animation in the following link: <a href=" I also go into ...

Recommended valve-to-piston clearance is generally 0.080-inch minimum on the intake side and 0.100-inch minimum for the exhaust valve. The exhaust needs a little more clearance because it expands ...

Piston Spool Valves. A spool valve features seals along its surface. By actuating the valve, the spool shifts, causing the seals to travel down the bore and opening the ports to allow for airflow.

The tightest clearance between valves and pistons does not occur at maximum valve lift, but instead at two places during the piston travel. The intake valve is closest to the piston in the ...