What is the operating temperature range of petrochemical pp diaphragm pressure gauge

Petrochemical PP diaphragm pressure gauge is a special instrument widely used in the petrochemical industry. With its excellent corrosion resistance and economy, it performs well in measuring the pressure of various corrosive media. Understanding the operating temperature range of PP diaphragm pressure gauge is crucial to ensure the long-term stable operation of the instrument and process safety.

Temperature resistance of polypropylene material
Polypropylene (PP) is a crystalline thermoplastic polymer with good chemical corrosion resistance and certain temperature resistance. Generally, the operating temperature range of PP material is roughly between -20℃ and +90℃. Beyond this range, the physical properties of polypropylene material may deteriorate, such as softening, deformation or brittle cracking.
In the petrochemical industry, the PP diaphragm, as the contact medium part of the pressure gauge, must ensure that it will not be damaged or degraded due to temperature changes during the measurement process. Especially in high temperature media or low temperature environment in winter, the performance stability of the polypropylene diaphragm directly affects the measurement accuracy and life of the instrument.

Typical operating temperature of PP diaphragm pressure gauge in the petrochemical industry
Usually, the operating temperature range of Petrochemical PP diaphragm pressure gauge is designed to be -10℃ to +80℃. Within this range, the polypropylene diaphragm can maintain good mechanical strength and sealing performance, and is suitable for pressure monitoring of a variety of petrochemical media. The specific upper and lower limits of the temperature can be adjusted appropriately according to the actual application environment and the characteristics of the medium.
In low-temperature environments, although polypropylene is relatively tough, if the temperature drops below -20°C, the material will gradually become brittle and there is a risk of cracking. To ensure safety, petrochemical plants should take corresponding insulation measures under extreme low temperature conditions, or use alternative materials with better low-temperature performance.
In terms of high temperature, when it exceeds 80°C, polypropylene begins to soften, the risk of diaphragm deformation increases, and the sealing and measurement accuracy of the pressure gauge may be affected. For high-temperature conditions, the use of high-temperature resistant fluoroplastic (such as PTFE) diaphragm pressure gauges should be considered to ensure stable instrument performance.

Effect of temperature on the performance of PP diaphragm pressure gauges
The impact of temperature changes on PP diaphragm pressure gauges is mainly reflected in the following aspects:
Changes in physical properties of materials
At low temperatures, the toughness of the polypropylene diaphragm decreases, and it is easy to crack or damage. At high temperatures, the softening of the material may cause the diaphragm to deform and affect pressure transmission.
Fluctuation of measurement accuracy
Temperature fluctuations cause changes in diaphragm elasticity, which may cause pointer offset or signal error, affecting measurement accuracy.
Stability of sealing performance
Severe temperature changes can easily cause expansion or contraction at the joints, resulting in seal failure and leakage risk.
Shortened service life
Long-term use near the temperature limit will accelerate material aging, shorten the life cycle of the pressure gauge, and increase maintenance and replacement costs.
Design measures to improve working temperature adaptability
In order to expand the working temperature range of PP diaphragm pressure gauges, manufacturers usually take the following design and process optimization measures:
Material modification
By adding reinforcing agents or copolymers, the thermal stability and cold resistance of polypropylene are improved.
Optimization of diaphragm structure
Adopt multi-layer composite diaphragm design to enhance mechanical strength and temperature adaptability.
Insulation protection
Insulation layers are set around the instrument housing and diaphragm to reduce the direct impact of the medium temperature on the diaphragm.
Customized high-temperature models
For special working conditions, PP diaphragm pressure gauge products that can withstand 90°C or even higher temperatures are developed.
The importance of choosing a PP diaphragm pressure gauge suitable for the working conditions
The media in the petrochemical industry are complex and changeable, and the working temperature of the pressure gauge is directly related to the reliability and safety of the measurement. Selecting a PP diaphragm pressure gauge that meets the actual temperature requirements can effectively prevent instrument failures and production accidents caused by material failure.