Equilibar GS Series Use And Startup

GS/GSD Series Precision Back Pressure Regulator

REGULATOR USE AND STARTUP

WARNING:
Make sure that you have read and understand these directions before using, installing, or
maintaining the Equilibar pressure regulator. Take steps to ensure this instruction manual reaches
the operator of this regulator and stays with the regulator throughout its lifetime. Use, installation,
operation, and maintenance of all pressurized products including this regulator must be performed
by personnel who are properly trained and qualified through experience or specific training.
Failure to properly observe the instructions contained in this document may result in, but is not
limited to:
• Serious personal injury or death
• Unconstrained release of the pressurized media
• Permanent damage to the pressure regulator and/or permanent
damage to connected equipment

BACKGROUND

The Equilibar® GS/GSD Series valves are precision back pressure regulators (BPR's).
These BPR's control the fluid pressure at the inlet "I" port. The Equilibar BPR controls the
inlet pressure by allowing excess flow to vent from the system through the regulator's
outlet "O" port. The flow direction is from inlet to outlet. The Equilibar BPR is pilot
operated, where the pressure setpoint is determined by the pressure applied to the
"Pilot" or "Reference" port on the BPR (see Fig. 1). The BPR will control the pressure at
its inlet port in a precise 1 to 1 relationship with the setpoint pressure applied to the
pilot port. The pilot pressure may be applied using a manual pressure regulator or an
electronic pressure regulator (electro-pneumatic regulator).
Refer to Fig. 1. The Equilibar BPR uses a flexible membrane diaphragm to both sense
the pressure and to provide a direct seal against the orifices in the regulator body. The
pilot pressure is applied to one side of the diaphragm. The Inlet "I" port pressure is
sensed on the other side of the diaphragm. When the pilot pressure is higher than the
Inlet pressure the diaphragm is pushed firmly against the orifices to form a seal and the
regulator is effectively closed. When the inlet pressure builds and just equals the pilot
pressure, the closing forces are removed from the diaphragm and media can begin to
pass from the Inlet to the Outlet port. When sufficient media has passed through the
regulator, the Inlet pressure will be reduced slightly, and the diaphragm is allowed to seal
against the orifices again. In normal practice equilibrium is achieved and the diaphragm
modulates into a position where just enough flow is allowed out of the regulator in
order to maintain a steady pressure on the Inlet port. (see Fig. 2)
Typical Circuits: A back pressure regulator is used to control the pressure in a system
by venting any excess flow that would otherwise cause the system pressure to increase
above the pilot setpoint pressure. In the example circuit shown, the BPR is used to
control the outlet pressure of a pump (see Fig. 3). Excess fluid is vented through the BPR
back to the fluid reservoir.
Another application for the Equilibar BPR is tank blanketing. In filling a tank with
product, the blanketing gas or vapours in the head space must be vented to a proper
disposal system to meet air quality and safety codes. Connecting the tank to the disposal
system though an Equilibar back pressure regulator achieves the goal of retaining a
slight positive pressure in the tank while relieving the excess pressure as the container
fills. Equilibar GS series back pressure regulators are ideal for this application and can
be remotely controlled by several pilot regulator options including electro-pneumatic
controllers driven by your process computer. Fig. 4 represents a typical drum or tank
filling installation.
Equilibar has trained engineers who can work with you to suggest a regulator design and
wetted materials for your specific application. These suggestions are recommendations
only and are dependent on complete and accurate information from the end user about
the application. It is the ultimate responsibility of the user to determine the compatibility
of the media with both the materials of construction of the back pressure regulator and
the pilot gas in use.
The diaphragm installed in the back pressure regulator is a careful balance between the
pressure, temperature, media compatibility, and flow rate. Often performance in one
area must be sacrificed to obtain acceptable performance in another. Many diaphragm
types cannot achieve tight shutoff and must have some minimum system flow always
present. If the system flow rate into the back pressure regulator is less than the minimum
flow rate required by the installed diaphragm, then the system pressure will fall below
the target setpoint pressure.
828.650.6590
©2010-2020 Equilibar, LLC
!
www.equilibar.com
30/8/20 R6
2 SET-POINT OPTIONS
Fig. 1
Electro-
Pneumatic
Regulator
E/P
- OR -
Pilot
(Reference)
Diaphragm
Inlet
Inlet
Pilot Regulator can
Fig. 2
be remotely located
Gauge
Media Pressure
is controlled here
Incoming
Media
Equilibar
©
Filter or Back Pressure
Strainer Regulator
Fig. 3
R
O I
Equilibar
©
Back Pressure
Regulator
Any Pump
Fig. 4
Air
Product
In
Equilibar
Back Pressure
Tank Regulator
Fill
Manual Pressure
Regulator
Outlet
Outlet
Pressure Reducing
Regulator, Relieving
Compressed
Gas Supply
Media is
vented
from the
outlet port
Reference
Pressure
Source
To
Application
To
Application
Scrubber
Or Vent
R
I O
©
Page 1 of 5