A pressure gauge (manometer) is a measuring device used to calculate the force exerted by a liquid or gas on a surface. As the name implies, an oil pressure gauge is a pressure gauge filled with a liquid, such as silicon or glycerin, to improve its performance in unnecessary situations. When the pressure gauge is not fully filled , liquid can be observed, causing air bubbles to form at the top of the gauge. Barometers are widely used in domestic, commercial and industrial applications. They are a quick indication of the pressure on the system to install, configure and operate equipment.
There are several reasons for filling a dry pressure gauge (also known as a normal pressure gauge) with liquid. However, to understand the basis of the oil pressure gauge, we need to review the pressure mechanism and its components.
How the oil pressure gauge works
The most common principle for measuring fluid pressure is the Bourdon tube. The Bourdon tube relies on the smooth effect that a flat or circular tube inserts when pressed. A pressure gauge using this principle consists of several parts, as shown below:
The following figure shows the internal mechanism of a Bourdon tube pressure gauge. Fluid enters the inlet pipe (A). The inlet pipe is held by a socket block (B), which also holds the machine to the process line. Fluid pressure flows to the fixed end of the Bourdon tube (C). The pressure is transmitted through Figure C to the movable end of the Bourdon tube (D). This pressure forces the C-shape to flatten. At the movable end of the Bourdon tube, an axial and axial base (E) connects the right-hand drive to the gear (F). The gear system amplifies the motion at the movable end of the Bourdon tube so that very little pressure change results in significant motion of the marker needle (G). The marker moves in a circular path, usually from left to right, on a calibrated scale.
The pressure gauge shown in the ideal environmental conditions and vibration-free equipment is sufficiently accurate and stable. Sensitive connections, axles, levers, gears and precision measuring indicators are damaged in severe working conditions. This damage leads to mismatch in the measurements, challenges reading the indicators, and leads to manometer failure, making the oil pressure gauge ideal. Read our pressure gauge article for more information.
Oil pressure gauge improves dry pressure by providing a liquid, usually glycerin or silicon, to protect the mechanisms and components of the pressure gauge. Conditions such as compressors or pressure washers, and other conditions such as vibration or humidity can cause damage. The fluid fills the entire pressure gauge, one side is in front of the gauge and the other side is the Bourdon tube pressure gauge. Air bubbles do not affect gauge reading regardless of orientation.
The viscosity of the filling fill provides the damping effect of the measurement. Various factors such as reaction time, vibration, sensitivity to pressure and temperature affect the choice of the type of liquid and the specific viscosity of that liquid. Because the pressure must overcome the viscosity of the oil pressure gauge from the liquid, its speed is slower, but this principle ensures that the pressure is more stable and fluctuates less. This ensures that the pressure gauge wears out less quickly.
The advantages of an oil pressure gauge are compared to the following pressure gauge.
Dry pressure gauge | Oil pressure gauge | |
It is difficult to read measurements on vibrating equipment | Easy to read The indicator stabilizes against vibrations and beats | Readability |
Faster wear due to higher frequency of parts movement | Liquid lubrication and reducing the frequency of movement of gears and joints cause less wear. | Confused wear |
High temperatures damage parts | Protected against high and extreme temperature fluctuations | Temperature protection |
Its density condenses in a humid environment, making it difficult to read. Moisture can also damage parts of the sphygmomanometer. | Condensation is not possible | liquidity |
It is not sealed and can not be used in corrosive environments. | It is sealed, so it is resistant to highly corrosive chemical processes such as the production of acids and salts. | Corrosion resistance |
Cheaper alternatives but higher replacement rates | More expensive, long lasting with cost savings | Price |
It creates condensed moisture inside the marker | Protection against sub-zero conditions (up to -40 degrees Celsius) | Performance in sub-zero environments |
Faster marker speed | Lower indicator speed due to liquid resistance | Marker speed |
Incompatible performance in severe conditions | Continuous performance in all conditions | Perform in severe conditions |
Criteria for selecting an oil pressure gauge
The general selection criteria for oil pressure gauges are basically the same as for dry manometers. However, there are some additional considerations when choosing an oil pressure gauge.
- Filling oil type : Filling oil type determines what unrealistic conditions to protect. Glycerin is commonly used to protect against vibration at room temperature, while silicone oil is commonly used for oscillating applications at high temperatures and high temperatures. Also, if the system is exposed to electrical contact with the environment, consider the type of oil. In this case, select the insulation oil.
- Cost-effectiveness : While oil pressure gauges have obvious advantages over dry pressure gauges, they are often more expensive for the same measurement range. For long-term use, the oil pressure gauge has a cost advantage. You do not need to use a pressure gauge if the program does not have vibration, shock, concern for congestion or extreme temperatures. Consider a dry pressure gauge instead.
In cases where the pressure gauge is filled with oil, they are usually minor, and if the sealing material is damaged and the scale and markers change color, it may leak after years of use. More information on selection criteria can be found in the Gage Selection Tips.
Oil pressure gauge applications
Oil pressure gauges have numerous applications in many processes with integrated conditions. Although they can be used to measure standard pressure, which is good enough to measure a dry gauge, an oil gauge is more suitable for the following applications:
- Compressor discharge pressure : Oil pressure gauge is used in compressor discharge due to high temperature and compressor vibrations.
- Hydraulic pressure gauges : Hydraulic pressure gauges are often oil pressure gauges that reach 1000 bar due to high pressure. These pressure gauges are used in hydraulic pumps, lubrication lines, control systems, hydraulic presses and..
- Dust, humid air or condensation conditions : In applications where the gauge is exposed to humid air or water, an oil pressure gauge is used. For example, the washer is under pressure. They are sealed and protected against the ingress of dust or moisture, which can affect the internal mechanisms of the pressure gauge. Confirm Gage IP rating.
- Freezing conditions : Oil pressure gauge is used in refrigeration systems such as supermarkets, warehouses, medical centers, etc., which work with filler liquid below zero degrees and has a freezing point below zero. (Glycerin works at -20 ° C, silicone oil works at -40 ° C)
- Corrosive environment : They are also used in environments with corrosive substances such as acids in chemical plants, which can damage the internal mechanisms of the pressure gauge. Confirm gauge compatibility with our chemical compatibility chart.
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