The service of inspecting pressure gauges and safety valves is to determine and examine the conformity of measuring instruments with legal requirements to meet specific technical standards or not, the results are determined by the state inspection agency as passed or not.
Inspection is mandatory for measuring instruments included in the "List of mandatory inspection equipment" according to Decision No. 13/2007/QD-BKHCN dated July 6, 2007 of the Ministry of Science and Technology.
What is a pressure gauge?
A pressure gauge that directly monitors pressure must be placed in a visible position on the service floor, the face of the pressure gauge must be inclined about 300 when placed above eye level.
For the pressure gauge to work reliably and accurately, it must be regularly checked and calibrated periodically or irregularly in the following cases:
- Before putting the device into operation.
- During the operation of the device if necessary.
- When the equipment is subject to periodic or irregular operational checks and inspections
Safety valve calibration includes the following steps:
- Visually check the technical condition of the valve;
- Use gas (compressed air, nitrogen) or liquid (water, specialized oil) to increase the pressure to check the impact pressure, closing pressure of the valve;
- Adjust to suit the actual situation;
- Check the tightness of the valve;
- Clamp lead.
What is a safety valve?
Spring-type safety valve: most commonly used.
- Counterweight-type safety valve (dumbbell): only used for fixed equipment.
- Membrane-type safety valve: often used for powdery media or media that can adhere and clump to conduct testing. When the pressure reaches the pressure to destroy the membrane, the membrane will burst, then another membrane must be replaced.
For the safety valve to work reliably and accurately, it must be regularly checked, periodically or irregularly calibrated in the following cases:
- Before putting the equipment into operation.
- During the operation of the equipment if deemed necessary.
- When the equipment is periodically or irregularly inspected and tested
