What is the principle of setting the root valve of the pressure gauge? Which gauges need to set the root valve? Which pressure gauges do not need to set the root valve?
Now the design specification of HG/T 21581 is the gate with the (DN15 SW of 23)
Under normal circumstances, are equipped with roots valve, you can certainly online replacement, maintenance. Specific selection of pipeline diameter, according to the nature of the medium, the gas generally choose 14mm diameter, liquid generally use 25mm diameter.
First, local pressure gauges (in the PID diagram of a component named PG) installation interface are flange, flange with general HG/T20615-2009 DN20, the minimum pressure rating to Class300, Class300 is higher than that of no special requirements and process piping class agreement. Flange pressure rating less than or equal to Class600 when using the RF process, the pressure level with RJ CLASS600. In the process of vertical pipe on the diaphragm type pressure gauge will require the use of a 90 degree bend flange pressure gauge of the nozzle surface into the vertical flange, and pipe insulation shall not collide, and the vertical direction for bolt and nut construction space. 3. outside the flange surface, within the flange 150mm, set aside the space required for the long 700mm instrument installation. Two, the general pressure transmitter pressure transmitter (in the PID diagram of a component named PT) installation interface are flange, flange with HG/T20615-2009 DN20, the minimum pressure rating to Class300, Class300 is higher than that of no special requirements and process piping class agreement. Flange pressure rating less than or equal to Class600 when using RF process, pressure rating >Class600 with RJ. Single flange pressure transmitter, flange nozzle adopts HG/T20615-2009 DN50, minimum pressure level is Class300, higher than Class300, no special requirements, and process piping level. Threaded interface flange pressure rating less than or equal to CLASS600 with RF when suddenly face we installed on the pressure gauge with the cut-off valve with DN15;
