Why is a bend usually added in front of a pressure gauge?

It is to cushion the impact of pressure fluctuations on the pressure gauge, prevent damage to it, and ensure stable readings on the gauge! ! ! ! ! !

Agree with the view from the 2nd floor; additional points: 1. The liquid formed by condensation in the gas can be recycled.

Agree with the second floor’s opinion! Additional note: It is not used in all situations; it is generally applied to hydraulic systems with large pressure fluctuations, such as at the outlets of pumps and compressors ； But elbow fittings are generally not used in gas piping systems.

The views on the 2nd and 5th floors are very comprehensive; they’re not for condensed liquids!

It also has a certain shock-absorbing effect, reducing the vibration of the hands!

The elbow installed in front of the pressure gauge, also known as an expansion elbow, is used for buffering.

The official name for a bent tube is a buffer tube; its main function is to reduce vibrations and shocks. It can also help dissipate heat from media with high temperatures, thereby protecting the pressure gauge and minimizing errors caused by temperature variations. The damping screws at the connection ports of some pressure gauges serve to provide throttling and buffering effects by reducing the flow area. It is mainly useful for dielectric pressure pulses.

Agree with and support the view from Floor 10; it provides a fairly comprehensive summary.

Pressure can act as a buffer inside bent pipes, providing shock absorption for instruments.

Generally, a steam elbow is used to facilitate condensation, preventing steam from entering the instruments directly and thus affecting their accuracy. It also serves to prevent expansion and provides corrosion protection and isolation. In summary, its functions are temperature reduction, vibration damping, buffering, isolation, and prevention of blockages. Such an elbow is commonly referred to as a condensation ring or condensation elbow

To summarize everyone's views: this elbow is generally referred to as a condensation elbow. It is used in conjunction with steam to facilitate condensation, preventing steam from entering the instruments directly and thus affecting their accuracy. It also serves to prevent expansion and provides corrosion protection and isolation. In general, it serves to reduce temperature, absorb shocks, provide cushioning, offer isolation, and prevent blockages. It is generally used at the outlets of liquid flow systems with large pressure fluctuations, such as pumps and compressors ； But elbow fittings are generally not used in gas piping systems.

I’ve organized it; I hope it will be helpful to everyone. Pressure gauge tubes generally have a diameter of 6 mm, while the damping holes in the connectors used to connect them to the pressure gauge are only 1–2 mm in size; bends are used to absorb vibrations. The gauge pointer also moves smoothly as pressure increases, which helps to reduce noise. Why are some pressure gauges equipped with a root valve, while others don’t? ? Those with root valves are generally used in important applications that require regular calibration, such as trade measurement and safety indication, or in situations where it is not possible to shut down the system for replacement. Those without a root valve are generally for indication purposes; there is also another case where it can be stopped to allow for replacement. Some liquid-filled pressure gauges have a switch (I don’t know its technical name); I’m not sure what it’s for A filled-pressure gauge is a shock-resistant pressure gauge that is typically used in high-pressure environments. It is equipped with a pressure gauge switch, which facilitates maintenance and repair. When long-term monitoring of the pressure is not necessary, turning off the pressure gauge switch also serves to protect the gauge, thereby extending its service life. Generally, manufacturers of pressure gauges need to consider the gauge’s compatibility under different air flow conditions. When the pressure exceeds its maximum tolerance level, the gauge may get damaged at the bend section, without damaging its critical components, as the cost of those parts is relatively low. This is a form of protection, and many devices abroad are designed with this feature. Filled-pressure gauges usually have high precision, and this helps to reduce vibration in moving components and wear on internal connection mechanisms, thus extending their service life. Typical pressure gauges have damping holes that serve to limit the flow rate at which pressure is transmitted. Pressure gauges used in boilers and pressure vessels are required, according to the \"Regulations on the Safety Supervision of Special Equipment,\" to be calibrated every six months, and the switches allow for easy removal of the pressure gauge.

Since the temperatures of some of the parameters being measured on site are very high, if the Bourdon tube in the pressure gauge comes into direct contact with such hot media, it will not only get damaged but also its elasticity will decrease due to the rise in temperature. This differs from the operating conditions assumed during the design and calibration by the manufacturer, resulting in inaccurate readings. It is also not possible for the manufacturer to produce different pressure gauges for measuring pressures in media at various temperatures. A elbow is placed in front of the pressure gauge; since there is condensed water or some other isolating fluid inside the elbow, the fluid that reaches the spring tube of the pressure gauge is a medium with a lower temperature and very little variation in temperature. This medium has nothing to do with the temperature of the fluid being measured. As a result, the operating conditions of the pressure gauge remain the same as those during its design and calibration, ensuring accurate readings. Moreover, the same pressure gauge can measure the pressure of different media, which brings great convenience to manufacturing and use. Additionally, the elbow also serves as a buffer, which helps to extend the service life of the pressure gauge.