How to choose the material for a differential pressure gauge?

Differential Pressure Gauge

The differential pressure gauge is an instrument used to measure the pressure difference between two points.It has two pressure interfaces (H high-pressure end, L low-pressure end).And monitoring (filters, clean rooms), measurement (flow, level), control (industrial processes).It is an important tool for ensuring the safe, efficient and stable operation of the system, as well as for achieving preventive maintenance. 

I,How to identify the model of a differential pressure gauge?                            
The model of a differential pressure gauge is usually composed of "series code + range + accuracy + installation method + special functions". Different manufacturers have slightly different naming rules, but the core parameters are the same. Understanding these points is sufficient:                            
·Series code: Represents the basic type of the instrument. For example, the YXC series is a magnetic-assisted point electrical contact differential pressure gauge (with alarm function), the CYW series is a micro-differential pressure gauge (suitable for low differential pressure scenarios), and the DP series is a general industrial differential pressure gauge.                            
·Range: Directly determines the measurement range. The units are mostly KPa, MPa or mbar. The selection should be based on the actual pressure difference requirement.                            
·Accuracy grade: Common grades are 0.5, 1.0, and 1.6. The smaller the number, the higher the accuracy (0.5 grade indicates that the error does not exceed 0.5% of the range). For precise measurement and control, higher grades should be selected; for ordinary monitoring, 1.0 grade is sufficient.

II,Disassembly of differential pressure gauge structure: 3 core components determine performance.                            
The structure of the differential pressure gauge is not complicated. The core consists of three parts: "sensing element + transmission mechanism + indication device". Each part directly affects the measurement stability.                            
·Sensing element: The "sensor" for differential pressure, responsible for converting differential pressure signals into mechanical displacement. Common types include diaphragm type (suitable for low differential pressure and corrosive environments), bellows type (with a larger measurement range and good shock resistance), and piston type (specifically for high differential pressure measurements).                            
·Transmission mechanism: The "converter" of the signal, which transmits the displacement of the sensing element to the pointer. For direct current, it is a lever gear transmission. High-quality differential pressure gauges will use rust-proof gears to reduce wear and extend the lifespan.                            
·Indicating device: The "display window" of the result, including the dial, pointer and glass panel. The dial needs to be marked with the range and graduation value, and the glass panel is mostly tempered glass (impact-resistant) or plexiglass (lightweight).        

III,How to choose the material? (Select it according to the needs for better durability.)                            
The selection of the material for the differential pressure gauge mainly depends on "the contact medium" and "the applicable environment". The recommended material for key parts is as follows:                            
·Case material: For normal environments, select cold-rolled steel (economical option); for humid/outdoor environments, select 304 stainless steel (anti-corrosion); for corrosive environments, select 316L stainless steel or polytetrafluoroethylene (resistant to acids and alkalis).                            
·Material of sensing element: For measuring gases/clean liquids, nitrile rubber (with good elasticity) is selected; for measuring oils/organic solvents, fluorine rubber (resistant to oil) is chosen; for measuring strong corrosive media (such as acid and alkali solutions), polytetrafluoroethylene is selected.                            
·Joint material: It is sufficient to match the material of the sensing element to avoid leakage or corrosion caused by material incompatibility. Commonly used materials are 304 stainless steel and brass (confirmation is required that the medium does not cause corrosion). 

IV,The three core principles for selecting a differential pressure gauge                            
·Initial requirements: Clearly define the measurement range, accuracy requirements, and medium characteristics to avoid "using too much equipment for a small task" or "insufficient measurement range".                            
·Now let's look at the environment: Based on factors such as temperature, humidity, and corrosiveness, determine the materials for the case and core components.  
·Trust quality: Prioritize choosing manufacturers with qualifications. Pay special attention to the smoothness of the transmission mechanism and the sealing performance of the joints to reduce maintenance troubles in the future.       

Summary:                            
The selection of pressure gauges may seem complicated, but by following the logic of "look at the parameters for the model, examine the core for the structure, and consider the environment for the material", one can easily find the suitable equipment. If you have any specific questions about the selection in a certain scenario, please feel free to leave a message in the backend!