FAQ

How to select a pressure gauge range?

Normally, choose the maximum range which is two times your operating pressure.
ASME B40.100 recommends pressure gauge should have a full-scale pressure such that operating pressure occurs in 25% to 75% of the scale to prevent pulsation.
What is the meaning of accuracy class?

The accuracy class is the permissible deviation of the indicated pressure.
For example, accuracy class 1% means acceptable error is within +/-1% of the full scale.
What is the difference between PT thread and NPT thread?

Both PT and NPT are taper threads, however, NPT thread have a 60 degrees included angle while it is 55 degrees for PT thread.
Why my pressure gauge pointing off of zero?

Many possible reasons may lead to off zero of a pressure gauge:
1. Internal pressure
Due to changes in temperature and altitude, there may keep pressure inside the pressure gauges (especially for low pressure gauges). In this case, simply pull out the oil plug or tip to release internal pressure.

2. Overpressure
Full scale pressure range should be 1.5 to 2 multiple the normal working pressure. Bourdon tube will be overstressed due to overpressure.

3. Clogging
Process media with high density will always stuck up a pressure gauge. Please use diaphragm seal (our P700 series) to prevent problem of clogging.

4. Mishandling
Gauges may be accidently damaged during transportation. Being crashed or rudely treated, it may become malfunctioned.
How to install pressure gauge / temperature gauge properly?

Please refer to our installation guide.
http://www.ccgroup.com.tw/files/OPERATING INSTRUCTION.pdf