MAIN BODY
While a spool design is typically used in piloted valves, the 26 series utilizes a poppet in the main
body. This technology is known as a Pilot Operated Poppet (POP) design. A standard spool type
design has 4 seals (bore and end seals), while a POP design only has 2 (end seals), equating to
reduced friction in the main body. This reduced friction results in greater repeatability over the life
of the valve. Another characteristic of a traditional spool type valve design is a longer stroke. This
is due to the spool having to travel out of the bore before air can flow. A POP valve needs only to
move off a seat for flow to be achieved, lending itself to additional speed when compared to a
spool design. Lastly, the 26 series takes advantage of MAC Valves patented conical seat design.
These seats reduce wear in the main body, thereby increasing the life of the valve.
PILOT VALVE
An optimized manifold mount Bullet valve® is used for the pilot of the 26 Series. In the standard
version, the pilot uses MAC “D” seals. The “D” seal design allows for controlled friction enabling
consistent responses.
MOD 8484
For demanding applications such as high speed dispensing, modification 8484 was created. This
modification includes high temp greases and Viton seals. In addition, the “D” seal in the Bullet
valve® pilot is replaced with a rolling diaphragm. This update offers superior performance over the competition as it relates to speed, life, and repeatability. Over the life of the 26 series valve with
the Diaphragm equipped Pilot, the response variation is cut in half as compared to the standard 26
series and far exceeds that of the competition.
