Precautions for instrumentation installation.

Precautions for instrumentation installation:

1. Instrument opening should avoid opening on the forming pipe.

2. Pay attention to the length of the straight pipe before and after the flow meter.

3. If the electromagnetic, mass and other flowmeter is required for grounding, it shall be grounded according to the instructions.

4. When welding the process pipe, the grounding line should avoid the instrument body and prevent the grounding current flowing through the instrument body and damaging the instrument.

5. Avoid grounding current flowing through a single, double-flange instrument's capillary tube during welding.

Argon arc welding or socket welding shall be used for the use of argon arc welding or socket welding. The wind speed >2m/s should be protected against wind. Otherwise, it should be covered with the coated wire, and the wind speed >8m/s must be equipped with the wind protection measures, otherwise the welding should be stopped.

7. Pay attention to the installation direction of the nozzle of the flowmeter throttling device.

8. The stainless steel pressure tube is strictly forbidden to simmer. It is strictly forbidden to simmer the pipe.

9. The installation position of the instrument pressure pipe, air duct and the tube shall be avoided in the future to prevent the operation of the process, and avoid the high-temperature corrosion site, and should be fixed firmly; The minimum leads should be lower than the inlet end of the connected meter. The lower end of the tube should be increased by three drops; Add y-type or conical explosion seal joint near the instrument side; The lowest part of the main wind line should be a drain valve.

10. The copper gaskets used in the instrument, such as non-annealing treatment, should be annealed before use, and pay attention to the allowable temperature, medium and pressure of various material gaskets.

11. In the field instrument junction box, the grounding of different grounding systems cannot be mixed together. The shielded wires of all instruments should be connected separately to the upper and lower shielding layer.

12. When the instrument is in a difficult position of observation and maintenance, party a agrees to change the position or install the platform.

13. In the middle of the instrument line, no connection is allowed. If special circumstances are reported to party a for approval, and a hidden record is made, the compensation wire joint shall be welded or pressed.

14. Stainless steel welding joints shall be pickling, passivation and neutralization.

15, to skim the instrument, pipe fittings, degreasing treatment should be in strict accordance with the specification, and make the instrument, the pipe sealing after degreasing, keeping work, fight was secondary pollution in the process of storage and installation.

16. Stainless steel pipes are strictly prohibited from direct contact with carbon steel.

17. Galvanized, aluminum alloy cable bridge is strictly forbidden to use electricity, gas welding, cutting and opening. It should be used to cut and open holes, such as toothless saw and special opening.

18. The stainless steel tube is strictly forbidden to use electricity, gas welding, cutting and opening, and shall be cut and opened by plasma or machine.

19. The instrument threading tube, cabinet and plate greater than 36V shall be connected to the ground. Less than or equal to 36V, the instrument threading pipe thread should be at least anti-rust treatment; The exposed wire should not be more than one thread.

20. The instrument tube of the explosion danger zone should maintain the continuity of the electrical.

21. A 250V meter is used to measure insulation resistance of the insulated instrument line of less than 100 volts, and is greater than 5 megohm.

22, aluminum alloy bridge should be short jumper wire, galvanized iron bridge should be not less than two locking screw, ends should be reliable grounding within 30 meters in length, more than 30 meters should be every 30 meters to increase a pick up location.

23. When the instrument line or instrument line of the different grounding system is Shared with the power line, the metal partition shall be separated.

In the installation and processing of the instrument panel, cabinet, box and platform, it is strictly prohibited to use the gas welding method. The welding method should not be used in the installation, and the mechanical opening method should be adopted in the opening.

25. The blind end of the meter with hot and backwater should not be greater than 100mm.

26. The nozzle of the transmitter drain valve should be increased to increase the pipe cap (especially in the explosion zone).

27, instrument and threading pipe, one end of pressure pipe is fixed with thermal expansion area (such as tower, tower thermal expansion of mobile accessories), one end fixed on the thermal expansion section (e.g., between the labor protection), connecting the instrument should be according to the actual situation, the flexible tube, threading pipe, pressure pipe thermal expansion must set aside a certain margin.

28. The attached tower bridge and tube shall have thermal expansion expansion joint or flexible connection according to the actual situation.

Other:

1. The copper pipe shall be connected with the socket welding, sleeve welding or card joint, the aluminum pipe shall be welded with the sleeve, and the oxide layer shall be removed before welding.

2. Special attention should be paid to measuring the connection between the measuring line and the measuring instrument. Piping for gas medium and low boiling liquid fluid shall be laid up; Pipelines carrying general liquids shall also be laid up.

3. To measure the pressure pipe of the liquid, in order to reduce the measurement error and improve the measurement precision, the outlet of the guide tube should be provided with a sufficient distance (greater than 500mm) in the horizontal direction of the minimum liquid level. Make sure the bottom level of the liquid level changes.

4. The pressure pipe at the bottom of the liquid surface should be inserted into the liquid container, and the nozzle should be down to avoid the influence of impurities.

5. The position of the outlet of the gas above the liquid container. It should be chosen to avoid the impact of liquid flow and fluid impact in the container. After the guide tube is drawn from the container, it should be mounted vertically upwards (generally greater than 150mm) and then laid in a horizontal direction.

6 large air separation equipment, pressure pipe installation guide should execute gauge pressure pipe installation guide technical standard, guide tube bending radius R = 5 d, guide pressure tube inside cold box should press the HTA1107-93, large air separation installation technology requirements, R = 10 d.

7, take source instrument parts, guide pressure pipe material to consistent with the process piping or equipment material requirements, especially toxic for the corrosive medium measurement source components and pressure pipe installation guide to check one by one before.

8. The welding technology requirements of the guide tube of the instrument's source components and instruments must be in accordance with the welding technology requirements of the process piping or equipment.

9, tank farm and device for explosion-proof requirement the instrument installation should pay attention to the explosion-proof requirements, grounding requirements strictly, protecting tube with the field instruments, instrument box, junction box, box seal should be paid attention to when connection, strictly according to the design requirements.