blog about pressure transmitters

PTFE lining for diaphragm seal pressure transmitters is used when the process medium is corrosive and metal wetted parts need chemical isolation. It is common in chemical liquids, acid and alkali applications, wastewater, and other aggressive media where 316L or normal metal materials may not be suitable. PTFE lining is not only a material choice. It changes the wetted structure of the diaphragm seal system. The lining, diaphragm, flange, gasket, temperature, and pressure conditions should be checked together. When PTFE Lining Is Useful PTFE lining is often considered when the medium may corrode the flange face or other exposed metal wetted parts. In some applications, using only a special diaphragm material is not enough because the flange or connection may also contact the process. PTFE lining may be useful for: Acidic liquids Alkaline liquids Mixed chemical wastewater Corrosive process liquids Applications where metal wetted parts need isolation However, the exact suitability still

Remote seal pressure transmitter fill fluid affects pressure transmission, response time, temperature stability, vacuum suitability, and long-term measurement performance. In a remote seal system, the process medium does not enter the sensor directly. The diaphragm receives the process pressure, and the fill fluid transfers that pressure through the sealed system. Because the fill fluid is hidden inside the seal and capillary, buyers may ignore it. But in high-temperature, low-temperature, vacuum, capillary, or sanitary applications, fill fluid selection can strongly affect performance. Temperature Influence Temperature is one of the main reasons fill fluid matters. Different fill fluids have different viscosity, expansion behavior, and temperature limits. If the fill fluid is not suitable for the process temperature, the transmitter may drift, respond slowly, or become unstable. For high-temperature service, the fill fluid must remain stable. For low-temperature service, it must not b

Pressure transmitter thread types such as NPT, BSP, G thread, and metric thread must be identified correctly before installation or replacement. Similar-looking threads are not always interchangeable. Choosing the wrong thread can cause leakage, poor sealing, damaged connections, or complete installation failure. This problem is especially common in replacement orders. Buyers may only provide photos or say “1/2 inch thread,” but different thread standards can look close while sealing in different ways. NPT Thread NPT is a tapered thread commonly used in many industrial and process applications. It seals by thread interference, usually with sealing tape or suitable sealant. Because it is tapered, it should not be treated the same as a parallel thread. A common example is 1/2 NPT. It may look similar to G1/2 at first glance, but it is not the same. BSP and G Thread BSP is a broader thread family. In pressure transmitter applications, buyers often see G thread, which is a parallel pipe th

Pressure transmitter process connection should be chosen according to the installation point, medium condition, pressure rating, cleaning requirement, and existing site connection. A transmitter with the correct range and output can still be unusable if the connection does not match the pipe, tank, valve, or equipment. Process connection is not just a mechanical detail. It affects installation, sealing, maintenance, cleaning, and sometimes material selection. Common Process Connection Types Threaded connections are common for clean gas, clean liquid, water, air, oil, and general pipeline pressure measurement. They are simple and economical, but they may not be suitable for sticky, dirty, crystallizing, or hygienic media. Flange connections are often used for tanks, vessels, diaphragm seal structures, corrosive media, or applications where a larger sensing surface is needed. Flange size, rating, standard, sealing face, and material must be confirmed before ordering. Tri-Clamp connection

Pressure transmitter wetted materials should be chosen by checking the medium, corrosion risk, temperature, connection structure, and which parts actually contact the process. Materials such as 316L, Hastelloy, tantalum, and PTFE are common in transmitter selection, but they are not interchangeable. A common mistake is asking which material is “best.” The better question is which material is suitable for the actual medium and working condition. 316L Stainless Steel 316L is the most common wetted material for general applications. It is often suitable for clean water, air, oil, and many mild industrial liquids. It is economical, available, and easy to use in standard pressure transmitter configurations. However, 316L is not a universal anti-corrosion material. If the medium contains strong acid, strong alkali, high chloride content, or aggressive chemical components, the supplier should check whether 316L is still acceptable. Hastelloy Hastelloy, especially Hastelloy C276, is often used

Diaphragm material for corrosive media should be selected according to the chemical type, concentration, temperature, and all wetted parts in the pressure transmitter connection. In corrosive applications, choosing the wrong diaphragm material can cause corrosion, leakage, unstable output, or early transmitter failure. Many buyers only ask for “anti-corrosion diaphragm material,” but this is not enough. No single material can handle every corrosive liquid. Acid, alkali, chloride, fluoride, mixed wastewater, and high-temperature chemical liquids may require completely different material choices. Start With the Medium The first step is to identify the real medium condition. A general word like “acid” or “chemical liquid” is too vague for reliable selection. The supplier needs to know what the liquid is and how aggressive it is under the actual working temperature. Before choosing diaphragm material, buyers should confirm: Chemical name and concentrationMaterial resistance changes greatly