FAQ Pressure gauges

Yes. Badotherm offers the possibility to put your own company logo on the dial. A complete dial design can be made as well with all colors and shapes to create the best dial face for the operating situation.

Pressure gauge principle is depending on the pressure range to be measured. Up to 600 mbar a capsule or diaphragm system is the only possibility. From 600 mbar up to 25 bar diaphragm and bourdon tube principles are possible. Above 25 bar bourdon tube principle gauges is the only possibility.

In order to make the right selection of a pressure gauge below information are essential:

-Dial Size
-Scale Range
-Measuring System
-Material Selection
-Mounting Option
-Process Connection
-Case filling
-Window Material
-Safety Level
-Accessories (if any)
-Certificate & Document requirements

It is critical that the materials of the gauge’s pressure system are suitable with the media that its measuring. Typical materials for the measuring system and the connection are:
-AISI 316 Bourdon tube / diaphragm / capsule / socket
-Alloy 400 Bourdon tube and socket / diaphragm

The safety pattern gauge is constructed for the oil & gas industries and are therefore designed to fulfil the highest safety standards. When constructed an additional solid baffle wall is welded between the measuring system and the dial. The window is safety glass and a full blow out back plate is mounted in the back. The standard industrial pressure gauge does not have these features and is executed with a blow out plug and can be supplied with different window materials.

The filled option for pressure gauges should be selected when the pressure gauge is installed in a vibration situation or a pulsating process pressure is present. These conditions can cause fluttering of the pointer and movement. The reading is not stable, difficult to read and the internal parts are subjected to wear. Another reason for case filling can be done to prevent fogging of the inside of the window. This can occur when the case inside and the ambient temperature are changing rapidly. Filling the gauge with several filling fluids (i.e. glycerin, silicone or halocarbons), reduces the side effect of vibration, thereby extending the life of the gauge and making reading easier.

Stainless steel pressure gauges are made to work up to the maximum scale value. However the readability is best between the 25% and 75% of the full scale value. When selecting a pressure gauge it is wise to select the full scale range 2x the normal operating pressure. For example, if an end-user’s process is working at 5 bar, a Pressure Gauge with a range of 0 to 10 bar should be selected. In case design pressures are to be met, then the gauges could be support with an extra ‘overrange protector’ accessory such as the BDT49.

There might be several reasons causing this problem. Each reason may require different solutions:

1. Changes in ambient temperatures: this may create an internal pressure within the casing due to changes of ambient temperatures. Check if the fill plug is pierced, or vent the case by means of opening the filling cap would solve the problem.
2.  Gauge might be in operation for a long period of time and hence out of calibration: you can send the gauge to Badotherm to be checked. The gauge can be checked on functioning and it can be adjusted and calibrated when needed.
3. The gauge might has fallen or exposed to physical shocks: as a result, the mechanism might be affected and therefore gauge might be damaged and not suitable for use anymore. The gauge needs adjustment and checking before putting it in use.
4. Gauge might be exposed to overrange or pressure spike: The gauges have a certain limit depending on the scale range and model. Normally gauges are protected up to 130% overrange. However, when this value is exceeded then the gauge cannot held and the tube or welds can be damaged. Therefore the pointer might not be at zero when not pressurized.