Fisher™ Type VSX Slam-Shut Overview, Animation, and Maintenance

This video is an overview, working animation, and maintenance demonstration of the Fisher Type VSX Slam Shut device. Topics covered are features and benefits, and setpoint adjustment and resetting procedure.

The Type VSX Slam-shut provides protection of the network, downstream of the associated regulator, by immediately shutting off the gas flow in case of an under or overpressure situation. Type VSX safety shutoff valve is known for easy in-line maintenance and high reliability levels.

Fisher VS100 slamshut►
Emerson Natural Gas Regulators ►

YouTube ►
LinkedIn ►
Emerson 365 Blog►
Facebook ►
Twitter ►

Video Transcript:
In this video we will talk about the benefits resetting and maintenance of a Fisher Type VSX Slamshut. Before performing any work, always be sure to read and follow all safety precautions as they are outlined in the instruction manual. Slam shut devices are designed to shut off the flow of gas to the downstream system in the event of pressure rising above or falling below predefined levels. The VSX Series slam shut products offer various benefits: Downstream system protection, Environmentally friendly with no leaking or venting to atmosphere, Bubble tight shutoff to downstream equipment and systems. Internal parts can be inspected and replaced without removing the body from the pipeline. Positive latch mechanism to avoid unintentional trips. There are two main parts of the VSX slam shut device, a body with a removable orifice enclosed by a bonnet, a VSX series controller. The pressure measuring element of the VSX series controller consists of a diaphragm that senses downstream pressure. When the downstream pressure increases above the overpressure shutoff setting, the diaphragm moves up. When the downstream pressure decreases below the under pressure shutoff setting, the diaphragm moves down. Both of these actions result in the rotation of the cam and the release of the positive latch. The valve plug spring moves the valve plug against the regulator port, stopping the flow of gas before opening the valve plug. An equal pressure balance on inlet and outlet sides is required in the event of exposure to an overpressure event that if I should be inspected for any damage that might have occurred an optional remote notification switch can be installed offering the capability to remotely notify the operator should a slam shut event occur ensure that the slam shut device and its springs correspond to the desired operating conditions of the associated regulator we are now going to show you the setpoint adjustment and resetting procedure for the VSX slam shut remove the closing cap increased the downstream pressure to the desired / pressure set point then rearm the unit and turn the outside adjusting screw ring clockwise until the unit trips use a flathead screwdriver to turn the over… the slam shut device should be inspected and maintained periodically the frequency of inspection and replacement of parts depends upon the severity of service conditions or the requirements of local state and federal rules and regulations if the slam shut device does not close at the desired pressures or leaks gas after closure repair or replace the device this will cover disassembling the unit to change the disk and orifice of the vsx slam shut device remove the four bolts connecting the vsx to the body pull the actuator away from the body check the orifice remaining in the body by running a fingernail around the top of the orifice to check for nicks if there is any damage replace check the disk by looking for any cuts or chunking if damaged replaced by removing the cotter pin and pulling the disk off replace with a new disk and replace the cotter pin add the two flange plates and replace the four bolts order replacement parts by finding the needed part number in the VSX instruction manual at the end of the kit you can find a list of individual part numbers or a full repair kit use these part numbers to order replacements through your Emerson sales office the VSX is a slam shut controller and protects against overpressure events and under pressure such as a broken pipe downstream the VSX is a standalone slam shut but has the option of adding a commercial service regulator to the body later if pressure regulation is needed the VSX is easy to reset and bring the line back into service slam shuts provide protection to equipment without releasing any gas to the atmosphere. This is a good option for critical areas where venting gas is not possible.