Brochure

14 GE Centrifugal & Axial Compressors
Casings
Depending on the compressor family the
casings can be
- Horizontally split
- Vertically split
Horizontally-split casings consist of two half
casings joined along the horizontal center-
line. All connections such as suction and
discharge nozzles, side stream nozzles (if any)
and oil piping are normally fitted to the lower
half so that the upper half becomes an easily
removable cover. The casings may be cast-
iron or cast or fabricated steel depending on
the compressor duty, service temperatures,
gas handled and compressor size.
Vertically split casings have different shapes
and thickness depending on the pressure
rating.
Casings up to 350 bars are steel cylinders
with end covers either bolted or secured by
shear rings. Nozzles can be welded to the
casing or machined directly.
Casings with ratings over 350 bars are cup-
shaped forgings with one end cover only. This
cover is secured to the casing by a patented
shear ring locking device.
Shear rings offer the advantage of being
simple to assemble and provide the
necessary sealing assurance for very high
gas pressures.
By removing the end cover it is possible to
remove the rotor diaphragm bundle assembly
and to gain access to the internal
components without removing the outer
casing which remains connected to the plant
piping package.
Diaphragms
Suction, intermediate and discharge
diaphragms create the
gas flow path within
the stationary
components. The
suction diaphragm
conveys the gas into
the eye of the first
impeller and can be
fitted with adjustable
guide vanes to
optimize the inlet flow
angle. Intermediate
diaphragms perform the dual function of
forming the diffuser passage (where gas
Compressor Components