A PNEUMATIC output pressure switch with non-bleed two-port output switching is available from AMS Instrumentation. These switches are designed for use on monitoring systems associated with natural gas transmission.
Typically the switch can be used to protect a system or pipeline from an abnormally high or low pressure which might result in the discharge of gas.
The switch has an integral 2-port changeover valve connected to a regulated natural gas supply. As the switch operates the output of this valve changes between the regulated supply pressure and zero.
This output can be used to control the operation of a valve which would then isolate the system.
For low pressure switching the output valve would typically be configured as normally closed (N.C.)to give an output above the set-point of the switch. This output is lost as the process pressure falls below the setpoint.
For high pressure switching the output valve would typically be configured as normally open (N.O.)to give an output below the set-point of the switch. This output is lost as the process pressure rises above the setpoint.
In either mode there is no continuous bleed of gas in either switched state. The only time gas is vented is during switching as the output falls from the supply pressure to zero. A tapped connection is provided on the vent port so that this gas can be piped away if necessary.
With an anodised aluminium or 316 stainless steel construction only 116mm long and 55mm diameter this Series 100 pressure switch is both compact and robust.
It provides high switching accuracy with low switching differentials (the change in process pressure required to change the output). Ten standard ranges provide setpoint adjustment pressures from 0.1 bar up to 80 bar.
This pressure switch can also be used on other applications requiring the switching of any dry inert gas that is compatible with the materials of construction.
AMS Instrumentation 03 9017 8225