Bourdon Tube Pressure Gauges - Helically Wound

The Direct Drive Difference

At 3D Instruments we believe that simple is beautiful. Replacing the antiquated C shape Bourdon Tube in our pressure gauges is a unique Helically Wound Bourdon, The Direct Drive Difference.
Our Bourdon coil is coupled directly to the shaft-pointer, the only moving part.

Fewer parts, fewer problems. Regular recalibration is eliminated because there are no complex wear-prone parts. Linearity is built-in; no span adjustment is necessary - ever. And 3D accuracy is maintained throughout the useful life of the gauge, many times longer than those old fashioned designs.

The 3D Direct Drive design gives instant response while resisting pointer pulsation. Overpressure? Even 150% of full scale will not affect the accuracy of most 3D gauges. And it takes pressures of 500% greater than dial range to result in sensing coil rupture. Even when subject to abuse, 3D Direct Drive gauges last longer.

All 3D gauges use the finest materials in construction. We construct our Bourdon Tube of Inconel X-750. This is a highly elastic material with excellent corrosion resistance. All other wetted parts are in 316SS. All materials are selected to be compatible with your most challenging applications.

The 3D Helical Bourdon Tube

The heart of the 3D Pressure Gauge is the Helically wound Inconel X-750 Bourdon Tube. Inconel was chosen because of its excellent resistance to corrosion and its elasticity. There are two types of helical Bourdon tubes: one is specifically designed for higher pressures and the other is designed for lower pressures. Each pressure range dictates subtle differences in Bourdon tube design and manufacturing method.

To the user the benefits of this painstaking high technology process are longer field life with inherent accuracy and span. As an assembly in the 3D Test or Process gauge our coil provides lower cost of ownership and easier field use, simply because our gauges do not fail or require recalibration. In testing, some 3D

3D Vs. Liquid Filled Gauges In Many Severe Applications

In many severe applications C-shape pressure gauge cases are filled with silicone liquid to dampen their movements and increase service life. Beside adding cost to the gauge, the liquid fill causes other problems. These are associated with loss of liquid fill, discoloration, and added maintenance difficulties.

In most instances a standard 3D TLG "Tough Little Gauge" can replace an old fashioned liquid filled gauge. Beside being less expensive, the 3D gauge will provide longer service life and much less field complications for your instrument personnel. Even against liquid fill, 3D gauges can last as much as ten times longer in severe services with pulsation or vibration. This has a dramatic effect on your cost of ownership. After all, 3D gauges are designed to work, and work for a
long time no matter what the application.