3D Instruments

Pinsuwan Co., Ltd.

Direct Drive Technology


Direct-Drive Technology provides the basis for long-lasting life and performance for any application. The single sensing element – Inconel X750 Bourdon tube – forms a simple, yet reliable foundation of durability, vibration resistance and pulsation dampening. The helically wound Bourdon tube eliminates the “moving part” weaknesses of standard “C-type” designs because there is only one working part and fewer moving parts translates into fewer problems. The absence of complex, wear-prone parts eliminates the need for regular re-calibration and linearity is built-in – no span adjustment is necessary – ever. Consequently, Direct-Drive gauges remain accurate and last longer than standard “C-tube” pressure gauges.




Users of direct drive technology replace their pressure gauges less frequently because the single sensing element protects the gauge from over pressure. In fact, direct drive gauges are designed with 150% over-pressure protection to maintain accuracy and reliability in the event of over pressure. Unlike the first generation “C-type” gauges, which have a ratchet mechanism that cannot withstand over pressure, the elastic helical Bourdon tube automatically absorbs the over pressure. In the end, the heat-treated element has an internal memory and automatically returns to its original accurate setting.


Inconel X750 is the ideal choice for direct-drive gauge coils. It has excellent corrosion resistance and high elasticity. The elasticity is very important because it allows the helical Bourdon tube to expand with increased pressure – expand to allow for several times the rated pressure – without losing its memory. This directly translates into long-life accuracy over wide pressure ranges and high cycle counts – the Inconel X750 material remembers – it doesn’t forget!


Direct drive technology prevents early failure by incorporating a standard burst parameter of up to five times scale – that is up to 500% greater than the dial range. For example, a 0 – 5,000 psi gauge has a burst of 25,000 psi, and occasional pressure spikes will not render the gauge useless. Even under abusive conditions, direct-drive gauges last longer.


Since the gauge has only one moving part and no wear points, direct drive gauges do not wear out. There is nothing to wear out. Direct-Drive gauges have proven, over many successful years in the field, they do not wear out. The dial connects directly to the helically wound Bourdon tube which replaces the many gears, springs and linkages of “C-type” pressure gauges.


Helical Bourdon tubes can be wound for a multitude of applications from full vacuum (30” Hg) to extremely high-pressure (10,000 psi).


Direct drive gauges reduce the overall cost of a given application through long life performance and maintaining accuracy. Direct-Drive gauges do not need to be replaced nearly as often as standard duty gauges and never require re-calibration. This not only saves on purchasing budgets, but on maintenance budgets as well.