1. P
SE Engineering of Hanover, Germany, a compressor
packager company, custom-designs each package
according to customer requirements. The continual
development of compressor configurations is an integral part
of the service the company provides.
“Our customers have every right to expect us to highlight
an optimized solution during the planning phase,” said Bernd
Schmidt, head of sales compression systems at PSE. “For
this reason, we always discuss new technologies and their
impact on equipment operation with our customers to con-
vince them of the added value.”
After the requirements profile is defined, the optimal
compressor is selected and equipped with the best pos-
sible components to ensure high efficiency, reliability and
environmental compatibility. A recent example from a gas-
gathering installation in Central Europe shows how PSE
achieves the best for its customers.
The challenge: constant feed pressure
Certain regions in Central Europe have produced and
stored natural gas for decades, as has been the case in an
area north of Vienna, Austria. In the gas-gathering applica-
tion in this example, it is possible to connect and disconnect
individual wells from among the interconnected natural gas
wells, depending on demand. To extract gas efficiently from
the wells and collect it for further transport via a pipeline,
the operator needed an appropriate compressor solution.
The challenge was to compensate for the varying operat-
ing states resulting from differing pressures as a function of
the number of connected gas wells, so as to ensure a con-
stant feed pressure into the pipeline. This instance requires
a compressor that meets API 618 (Fifth Edition) [1] to com-
press the moist natural gas from a fluctuating suction pres-
sure to a constant pipeline pressure for transport purposes.
Electric stepless capacity control
PSE for the first time fitted a new single-stage Ariel JGC/2
with an all-electric capacity control system. By providing
stepless operation between minimal part load and full load,
this allowed customized production from the individual gas
wells. Thanks to its high-speed control dynamics, the sys-
tem ensures a constant gas pressure to supply the pipeline.
The system chosen by PSE is eHydroCOM, made by
Hoerbiger. This all-electric solution incorporates field ex-
Compressor Packager PSE Engineering:
Tailor-Made > Continual development provides added value
BY ROBERTO CHELLINI
n Single-stage compressor cylinder
with four electric actuators.
REPRINTED FROM JANUARY-FEBRUARY 2015 COMPRESSORtech2
Copyright Diesel & Gas Turbine Publications
Printed in U.S.A.

2. perience gained from more than 1100 in-
stalled electrohydraulic control systems. The
elimination of hydraulic components and pipe
couplings, and the absence of an additional
cooling system, makes the electric model an
extremely compact unit. Both the actuator and
the electrical power unit (EPU) require little
space and are connected by a single cable to
supply the power and data. Just one cable is
also needed to connect the EPU to the control
cabinet — another key factor in the high effi-
ciency of the stepless capacity control system,
which offers considerable energy savings over
conventional bypass solutions.
“Control of the compressor’s output must
be fast and customizable,” Schmidt said. “In
this application, energy-efficient operation
that meets the specified constant pipeline
pressure is the key requirement, so we pro-
posed an advanced capacity control system
to our customer for configuring and equipping
the compressor.
“Since we were the first to report good ex-
periences with the Hoerbiger electrohydraulic
reverse flow control systems in Ariel com-
pressors, this time we introduced the electric
variant, which is half the price of common
frequency converters. The customer followed
this recommendation and recently confirmed
that, in addition to smooth and efficient operation, recent measure-
ments have shown the Ariel compressor equipped with eHydroCOM to
run even more smoothly, in terms of vibration, than comparable base-
mounted equipment.” CT2
See references at: http://ct2.co/references
REPRINTED FROM JANUARY-FEBRUARY 2015 COMPRESSORtech2
Copyright Diesel & Gas Turbine Publications
Printed in U.S.A.
n System layout of an eHydroCOM
stepless capacity control system.
n For the first time PSE fitted the Ariel JGC/2 natural
gas two-cylinder, single-stage compressor package
with a new eHydroCOM capacity control system.