Pressure Gauge

A pressure Gauge measuring and indicating an instrument without external power that shows the accurate process/fluid pressure by using the mechanical sensing elements like bellow, bourdon, or diaphragm type based on force balance principle.

Components of Pressure Gauge

The main components of a pressure gauge are the dial, pointer, ring/lens gasket, window/glass lens, movement, sensing element, and the case. Consider the environmental condition when selecting a pressure gauge including ambient temperature, condensation, humidity, water, and chemicals, all of which can affect gauge performance.

Case: It is generally known as housing and keeps all other materials inside and along within it. The case is made up of aluminum, steel, brass, polypropylene, and stainless steel based on the applications and mounting environments. As per mounting style surface mounting, flush-mounting, or pipeline mounting cases are back flange, front flange, and turret types.

Dial: These are made up of steel, brass, aluminum, and plastic, with black marking lines on a white background or in other color combinations. Near major marking lines, the numerals are placed. Sometimes there are two rings of marking lines shown in different units as per the requirement.

Dial Size: It comes in different sizes and chooses as per the process requirements. It ranges from “1 to 16” diameters.

Accuracy: It ranges from 0.1 to 4 and chose as per the application. For a pointer stop gauge, the accuracy class will cover from 10 % to 100 % of the scale range.

Pointer: Generally, it is a bar navigate to show the pressure value by indicating the numerals, fixed with the shaft. Industrial gauges are made with adjustable pointers which adjust by turning the hub while keeping the shaft fixed.

Ring / Lens Gasket: It keeps the window/glass lens fixed. Ring attached to the case in different ways, including snap, friction, slip, threaded, and hinged designs. The look of the gauge can also be affected by ring design variations, including peaked, flat-flared, and beaded gauges.

Window/Glass Lens: It is held against the case front by rings. Materials for the construction of the lens are available including shatterproof, beveled glass or cellulose acetate, non-electrostatic plastics, etc.

Movement: The mechanism that connects the sensing element and the pointer to show the deflection known as a movement in general. It situates in between the dial and the case and protects both.

Sensing Element: Pressure gauges generally use mechanical pressure sensors as sensing elements and deflect the pointer using shaft movement or different types of mechanism arrangement. Pressure sensor material depends on the process fluid and should be compatible. Otherwise, it stops working or causes a hazard to personnel or deviates accuracy.

Type of Display: Mainly designed as analog or digital displays. Digital displays are used in certain applications even if analog pressure gauges are the most popular.

Mounting Pattern/Type of mounting: It depends on the location and type of connection. (For example, Direct/wall/surface/panel, Bottom/Back connection)

Pressure gauges are manufactured by considering safety standards which contain at least a blowdown disk that allows the internal pressure to escape. General process connections of pressure gauges are either 1/4in or 1/2in size and located either on the back or on the bottom. The factors mentioned above are the key points we need to consider before deciding to select a pressure gauge because improper selection can cause failure and possible personal injury or property damage.

List of prominent suppliers: ABB Inc., Accutech, Ametek Inc., Anderson Instrument Co. Inc., Ashcroft Inc., Barton Instruments Systems, Bristol Babcock, Dresser Instrument, Dwyer Instruments, Endress+Hauser Inc., Fisher Controls, Flow-Tech, The Foxboro Co., Honeywell Inc., Measurement Specialties, Mid-West Instrument, MKS Instrument, Nuova-Fima, OCI Instruments Inc., Omega Engineering, Parker Filtra