Page 161 - Reciprocating Compressors Operation Maintenance

Operation and Maintenance of Reciprocating Compressors t 47

TABLE 3-6
VALVE PLATE MATERIAL SELECTION
(WOOLLATT, DRESSER-RAND co.)

CONDITION COMMENTS GLASS 410 S3 OTHER CUSHION
NYLON METALLIC
Corrosive elements H 2S, chlorides. E P G G
in gas COj and H 2O

High ratio gas
High discharge with high k-value
temperature X E E G
(>300°For 180°C)
Dirty gas Dirt will embed In 6 P P p
glass nylon

High differentia!
pressure X E E E
{ > 1000 psi)

Unloading by plate Plug unloaders X G G G
preferred
depressors

Liquid slugs P P P P

Can occur with
High impact high MW, at high E G P E
pressure or at
high speed
Occurs if springs
Flutter too heavy or lift
too high,
especially at low P X X X
speed with low
MWaas
E= EXCELLENT G = Gooo P = POOR X = CANNOT USE

* They cause seat wear. Serious damage can result if portions of failed
elements get into the cylinder.
* They are easily damaged by dirt and liquids.

For most applications, 410 stainless steel is used but 302, 316, 420,
17-4 PH stainless steel, monel, Inconel, or even titanium are used for
special applications.