Edmonton Valve & Fitting Blog

Weekly posts for northern and central Alberta engineers, plant operators, and buyers.

5 Facts About Swagelok Gauges

by Taryn Hardes, on Wed, Mar 05, 2014 @ 14:03 PM

We already gave you the five laws of gauge installation - now we have five facts about the gauges themselves.

1. Most gauges mechanically measure pressure using a bourdon tube

A bourdon tube works as a sensing element. Bourdon tubes, which are commonly found in Swagelok gauges, work like a party horn. It will try to flatten itself with an increase in pressure, which pulls up on the lever which pulls the dial to show the appropriate pressure reading. A decrease in pressure allows the bourdon tube to return to its original C shape. Another option is a diaphragm, which are typically used for lower pressures gauges such as the L Model.

2. You’ll get your most accurate reading in the middle third of the dial 

Swagelok Gauge "Sweet Spot"  


When choosing the right gauge for a job, be sure to select a range that allows your normal system to fall in the centre of the dial. For example, if your system pressure is 100 psi, consider using a 200 psi gauge.


3. Bigger dials are more accurate 

Some Swagelok gauges are available in a variety of face diameters. Normally the larger the dial diameter, the more accurate the reading. Try to use as large of a face as you can in highly sensitive applications.

4. There are three mount configuration options for your convenience

Swagelok Gauge Mount Options

Swagelok gauges comes in a lower back mount, centre back mount, and lower mount for your convenience. Lower mount is most common, available on every Swagelok gauges series.

5. Gauges can come with a Tube Adapter end connection to allow for ideal alignment 

Swagelok Tube Adapter  

Many gauge designs utilize pipe fittings to connect the gauge into a system. This can create alignment issues and can even risk leaks by NPT threads being over or under tightened. Swagelok Pressure Gauges offer a unique end connection option that simplifies installation – the Swagelok Tube Adapter.

Swagelok Tube Adapter end connections eliminate alignment problems because the gauge dial can be aligned to the desired position and then remain stationary during pull-up of the fitting.


To learn more about the pressure gauge products available from Swagelok, download the Pressure Gauge catalogue.


Topics:Measurement Devices

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