Protection of pressure measuring equipment
The fluid that needs to be measured inside a pipe or tank can have different states. Vapors are corrosive or may fluctuate. Special devices should be used to prevent adverse effects on pressure measuring equipment.
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Tremor
The fluid pressure does not change, but the skeleton vibrates and the pressure sensor vibrates. By moving the pressure sensor to a fixed column and using hoses (or capillary tubes) that can withstand the fluid pressure, we eliminate the vibration effect.
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Oscillation
The fluid oscillates and is transmitted to the pressure sensor, causing the hand to vibrate in the pressure gauge and damage the pressure transmitter module. To prevent this phenomenon, a device called a pulsation dampener is used.
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Corrosive liquids and gases
They use a device called a barrier diaphragm to prevent liquids and corrosive gases from entering the pressure measuring equipment. Another name for this device is Chemical Attachment. This device has two compartments that are separated by a metal membrane made of stainless steel.
The upper chamber of the metal membrane, or diaphragm, on which the pressure measuring equipment is mounted, is filled with oil in a special way. During operation, the corrosive liquid is placed under the metal membrane and its pressure is transmitted to the pressure sensor through the oil.
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Steam
In the case of water vapor and gases that liquefy at ambient temperature, a device called a siphon is used. This device causes the pressure gauge to be in contact with the liquid and water or gas vapor does not enter the pipe.
The most common peripherals for measuring pressure
Accessories for pressure measuring equipment are mechanical devices used to connect a pressure gauge or pressure transmitter to minimize any damage to the pressure measuring instrument from the fluid being measured.
Why use peripherals for measuring pressure?
Pressure gauges are mechanical pressure gauges used to measure gauge pressure, absolute pressure, or pressure difference. Although relatively strong, they are prone to damage from the measurement process. Excessive pressure, extreme temperatures, pulsating pressure, etc. To help reduce the risk of damage to pressure measuring equipment, manufacturers and suppliers can install a wide range of accessories with a measuring device.
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Siphon tube
A pressure gauge siphon tube is a device installed to protect the meter against high temperatures. Siphons are used in steam applications and are especially common in steam systems. The hot steam condenses inside the siphon coil, which prevents high temperature vapors from reaching the pressure sensor element. The dense vapor transfers the pressure to the tube of the measuring element, allowing the measurement to be placed at a distance from the actual point where the pressure is being measured. In steam applications, it is common for the siphon tube to fill with water when the gauge is installed. There are two common types of siphon tubes: “U” and ring type. The ring type is often referred to as a pigtail. The choice of “U” or pigtail depends on the direction of the pipe and the available space.
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Mini siphon
The mini-siphon is a relatively new accessory designed to replace pigtail and “U” siphons. This device is made with an internal thermal barrier that protects the pressure measuring instrument against harmful vapors, hot vapors and liquids.
It is also claimed that by installing tools close to the process, the mini-siphon eliminates the whipping and vibration commonly found in cellophanes.
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Pressure sensor sniper
Pressure sensor sniper, or pressure limiter, is a device used to reduce pressure and pressure fluctuations caused by reciprocating pumps and compressors. This smoothing effect provides a more accurate pressure gauge and increases the service life of the pressure sensor. In addition, a stabilizer can increase the time between calibration of the pressure sensor.
There are different types of snipers, including porous snipers, piston snipers and throttling snipers.
Porous snubs are suitable for general applications.
Piston snipers are generally supplied with two or more pistons to suit different applications.
Throttlers have an internal needle valve or a variable orifice that allows you to adjust the amount of external adhesion.
Overpressure (pressure protector)
Excessive pressure guard is used to protect the pressure gauge against the effects of pressures that are greater than the maximum pressure gauge pressure. This equipment prevents premature calibration and damage to the internal components of the pressure gauge and rupture of the sensor element. At the preset pressure, the overpressure cuts off the pressure to the pressure gauge. When the pressure drops 10% of the set pressure, the overpressure (pressure protector) sets the pressure again. Although this is different in manufacturers.
Although the set point pressure is externally adjustable, you usually buy extra protectors when buying a meter. In this case, it is common for the overpressure protector to be set to 1.1 on the factory-protected maximum measurement scale. Excessive pressure protectors allow the installation of several pressure gauges with different pressure ranges in the ascending stages, allowing even low readings to be read accurately, while the total range is actually much larger. .
Cooling element (cooling)
Pressure gauge cooling elements, often called cooling towers, are used when the temperature of the process fluid exceeds the allowable temperature of the pressure gauge. Through air circulation and thermal radiation in the cooling element (cooling), the temperature of the process fluid in contact with the inside of the pressure gauge is reduced enough so that it does not exceed the temperature range and the possible temperature error is reduced. A pressure gauge cooling element can also be used to heat cold equipment, provided the ambient temperature is higher than the fluid temperature.
Manifold
Manifolds, also known as block and bleed valves.
Manifolds have different models and have several ways that are different depending on their application. The main job of manifolds is to remove air or trapped fluid and to replace pressure measuring equipment.
Semen folds are mostly used in pressure gauges, pressure difference gauges, pressure transmitters and pressure difference transmitters. In general, manifolds used in pressure equipment are divided into three categories: two-way manifold, three-way manifold and five-way manifold.
Pressure gauge rotary adapter
A swivel gauge adapter makes it easy to orient the pressure gauge in any direction through 360 degrees. This allows the dial dial to be visible to the operator. Some manufacturers offer rotary gauge adapters in which the male and female threads differ from the female in the parts to be connected.
Flood diaphragm
They use a device called a flood diaphragm to prevent corrosive liquids and gases from entering the pressure measuring equipment. This device has two compartments that are separated by a metal membrane made of stainless steel.
The upper chamber of the metal membrane, or diaphragm, on which the pressure measuring equipment is mounted, is filled with oil in a special way. During operation, the corrosive liquid is placed under the metal membrane and its pressure is transmitted to the pressure sensor through the oil.