Page 157 - Reciprocating Compressors Operation Maintenance

Operation and Maintenance of Reciprocating Compressors 1 43

Ported Plate Valves

Ported plate valves are similar to the concentric ring valves, except the
rings are joined together into a single element (Figure 3-17).
There are two advantages to this when compared to the concentric plates:

* The number of plate edges available for impact is reduced.
• Mechanical damping by using damping plates to absorb opening
impact is easily introduced.

Spring is generally provided by coil springs that directly contact the
plates, eliminating the buttons used in concentric ring valves.
The flow efficiency of these valves is roughly equivalent to the con-
centric ring valves, but the geometry of the sealing element is not as flex-
ible as the concentric ring valves. For this reason, the ported plate valve

FIGURE 3-17. Ported plate valves for lubricated (left) and non-lubricated
compressors (right) (Source: France Compressor Products, Newton,
Pennsylvania).