Super User VDM Anti-Vibration Anti-Vibration Viscous Damped Movement When a gauge suffers from the effects of vibration or pulsations, the pointer vibrates very rapidly making it very difficult to make accurate stable readings. The main cause of this effect is installing a gauge close to a pump or any process that vibrates in normal operating conditions. The key reason for fitting either a viscous damped Movement (VDM) or filling a case with glycerine is to overcome the effects of vibration and pulsation. It must be stated, however, that it does NOT replace a check screw or a pressure snubber for major pressure fluctuations or vibrations that are continuous and problematic, both of which can be supplied fitted into the inlet of the gauge. contact us for pricing and availability of the Budenberg VDM Anti-Vibration Viscous Damped Movement The Budenberg VDM is suitable for the following applications / industries Oil & Gas Pressure Gauge Chemical Pressure Gauge Petrochemical Pressure Gauge Power Generation Pressure Gauge Water & Waste Water Pressure Gauge Food & Beverage Pressure Gauge Pharmaceutical Pressure Gauge Refrigeration Pressure Gauge Glycerine filling A simple damping method is to fill the case with a viscous fluid such as glycerine to restrict hte point from rapidly performing small fluctuations resulting in potentially inaccurate readings. One of the key problems with this is whilst the poiner is bieng restricted other parts of hte gauge are still moving, hence the units suffer internal wear that may cause a premature failure of the instrument. Disadvantages of glycerine filled cases The action of dragging the pointer through the viscous fluids adds a load to the pointer htat can result in accuracy errors. The unit weight is effectively doubled, that puts extra strain on the installation, particularly on small schedule pipes. Units are very messy during recalibration whereby they have to be emptied and there is a chance that the fluid can leak out that could then cause a Health & Safety hazard. Benefits of Viscous Damped Movements Damping effect is applied to the mechanism at two key operational points. No loss or degradation of accuracy. Easier to recalibrateiwth no messy fluids to remove/replace. Unit weight is half that of a filled gauge. Increased life cycle - Budenberg guarantee a unit fitted with a damped movement for 1,000,000 cycles where the guarantee for filled gauges is only 200,000. Double Viscous Damped Movements These movements have been around for quite a number of years but only in the past 10 years has the design been developled and improved to meet the harsher demands, particularly in the off-shore oil and gas markets. They are very similar to the standard gauge movemnets by they provide direct damping onto the two key elements of the movemnet via silicon oil filled dashpots. These dashpots are located on the pinion and the guadrant arm and comprise of small white cylindrical containers filled with a viscous silicon oil and internal paddle wheels created resistance for the pointer from small flucuations of pressure or vibration just as glycerine filling would. Furthermore, the quadrant nylon teeth providing a smooth action and preventing metal to metal wear between the pinion and the teeth. The Pressure Gauge Anit-Vibration Viscous Damped Movement is suited to the following gauges: Standard Gauges from 63mm through to 250mm Schaffer Diaphragm seal gauges Chemical Seal Gauges Temperature gauges - both Mercury & Gas Filled To view all the information on the Budenberg VDM you can download the data sheet here DOWNLOAD PDF
