Moniteur VPT Product Selection Guidelines

Functions of Moniteur VPTs

Moniteur Valve Position Transmitters have been developed for automated quarter-turn and linear valves found in all types of industrial processing facilities. They have three functions:

1. Visual Indication of Valve Position – a high visibility indicator displays the valve position from distance up to 250 feet.
2. Electrical Feedback of Valve Position
3. Local Junction Box for Switches, Solenoid and additional local components

Functional Considerations

1. A full range of visual indicators have been developed for virtually any process valve.
2. A comprehensive selection of switches and sensors is available for all types of industrial applications.
3. The Junction housings can be fitted with up to 3 conduit entries and 26 terminal points.

Hazardous area and environmental considerations must be taken into account when selecting the proper VPT for your application!

Hazardous Area Rating

Make sure the position transmitter has the correct agency approval that is required for the installation. Agency approvals for each model are listed on their web pages. Be careful not to “over-select”, for example, Intrinsically Safe sensors in an explosion-proof enclosure. Contact Us and we will help you select the right product if you need technical assistance.

A Word About Intrinsically Safe Applications

Moniteur offers three switch/sensor options for Intrinsically Safe applications. Not all require approval for installation in a hazardous environment.

Gold Plated Mechanical Switches:

They are the most cost effective switch option. The gold plating provides protection against surface corrosion, and lowers the contact resistance of the switch. These features are important because the signal levels (often 10 mA at 8 VDC) are very low.

Rhodium TTL Non-Contact Switches

They are better than Gold Plated switches because all contacts are hermetically sealed from the environment. The Rhodium contacts also have low contact resistance and are stable down to 5mA @ 1VDC.

NAMUR Intrinsically Safe Sensors

These sensors from P&F or Efector are FM approved Intrinsically Safe and require the appropriate signal amplifier and barrier to be used with them. Moniteur includes documentation stating the FM approval in the box.

Because switches are passive devices and classified as simple apparatus, no approval is required by the electrical code for these to be installed within a hazardous area, as long as they are used with the appropriate voltage and current limiting barriers.

Sensors

Sensors are electronic and solid state, therefore consuming electric power to operate. Under the code, they require approval to be installed in a hazardous area.

Environmental Rating / Corrosion Resistance

Valve Position Transmitters and often placed in dirty, corrosive, or humid environments. Standard VPTs with aluminum enclosures and mechanical switches might not survive the environment. Options:

*Enclosure.

Choose the Survivor Series of Zytel enclosures, Watchman II Stainless Steel enclosures, or select the option to hard anodize the standard enclosures.

*Switches/Sensors

Use TTL encapsulated non-contact switches or inductive sensors with all critical parts protected from the environment.

*Bearing

303 SS Bearings are available in place of the standard Bronze

*Shaft.

316 SS Shafts are available in place of the standard 303SS.

Temperature Rating

Moniteur offers a line of VPTs rated up to 320 degrees F at competitive prices. Contact Moniteur for more information

Two Stage (Dribble Control) Package

A low cost two-stage shutoff package has been developed for dribble control or flow dampening applications. Download Catalog Sheet