Pressure gauges are an important part of so many industries, and in theory, they’re an extremely basic piece of equipment. However, that doesn’t mean they stay in great working order forever. Here’s everything you need to know about adjusting and repairing a faulty pressure gauge.
Why would a pressure gauge need adjustment?
There are a few signs you might need to recalibrate your pressure gauge. The needle can become stuck, or not go back to zero. The gauge can also simply be out of calibration, well above the standard tolerance.
There are many causes for pressure gauges failing, with some of the common ones being:
- Wear in mechanical parts
- Changes in altitude or temperature
- Exposure to excessive vibrations
Many of these problems are unavoidable, depending on what you’re using a pressure gauge for. However, there are fortunately plenty of ways to adjust and repair damaged gauges.
Tips for pressure gauge adjustment and repair
We should note that some pressure gauge faults are simply beyond economical repair, and replacement is necessary. This is generally the case if you see signs of corrosion or leakage, damaged sockets and threads or readings that are too far out of normal calibration. However, for other issues, these tips below can get your gauge working properly again.
1. Release pressure build-up through the vent
Many pressure gauges have a clearly visible vent. In circumstances where altitude or temperature has changed, pressure has likely built up inside the gauge, preventing the needle from returning to zero. If this is the case, simply turn the vent to the open position, release the pressure and the needle should return to zero.
This is the easiest way to adjust your gauge, but always remember to close the vent when you’re done.
2. Use the adjustable pressure knob
Another simple way to adjust your pressure gauge is using the pressure knob. Not all pressure gauges have this function, but if yours does, you’re in luck. The knob usually has a lock, so simply remove this and turn it to adjust the needle accordingly.
When using this method, ensure your pressure gauge is inactive, because it’s much easier to return the needle to zero.
3. Adjust the screw inside the pressure gauge
Some pressure gauges have an adjustable screw somewhere inside the mechanism. Depending on the type of gauge, this could be in the dial face, at the back of the needle, or even on the needle itself. For most adjustable screws, you just need to turn them accordingly to return to zero.
However, for the screws on the needle itself, you need to carefully loosen the screw and manually turn the needle back to zero. Then, tighten the screw again.
We should note that oil-filled pressure gauges are more complex, particularly if you need to remove the cover. In fact, there are many oil-filled gauges with sealed covers. If you’re unsure, consult your local experts.
Don’t forget to verify the adjustment
When you’re finished with any of these techniques, don’t forget to verify the gauge. Essentially, this means checking that everything still works the way it should. With your needle returned to zero, apply a pre-determined amount of pressure and make sure the reading is correct. Then, ensure the needle also returns to zero.
Need help with pressure gauge calibration?
If you need professional pressure gauge calibration or repair, please don’t hesitate to contact the team at National Weighing and Instruments today. We’re the specialists you can trust to keep your systems working correctly.