Requirements for valves associated with pressure gauges in pressure facilities

Thread Content

A3.5.6 Inspection items for pressure gauges (1) Whether the selection of pressure gauges meets the requirements； (2) Pressure gauge regular inspection and maintenance system: whether the calibration validity period and seals meet the requirements ； (3) Do the appearance, accuracy class, range, and dial diameter of the pressure gauge meet the requirements? ； (4) Whether the location of the three-way stopcock or needle valve installed between the pressure gauge and the pipeline, its opening indication, and its locking device meet the requirements ； (5) Whether the readings of the pressure gauges on the same system are reasonable. During inspections, issues such as incorrect selection of pressure gauges, broken glass on the gauge face, unclear markings on the dial, damaged seals, expiration of the calibration period, leaks in the Bourdon tube, loose or distorted pointers, severe corrosion of the casing, unclear indication marks on the three-way valves or needle valves, and damaged locking mechanisms were found. The using unit must take effective measures to ensure the safe operation of the pipeline; otherwise, its operation must be suspended. Which company can provide the aforementioned valves that meet the requirements? The rotary stopcock used easily leaks; is there a reliable one? Why is it necessary to specifically mention plug valves in the standards? What is the minimum size of a needle valve seat called? Why not say stop valve or add a stop valve?