A cold-box installation problems
1.1 Cold-box pressure test leak

Cold case investigation process piping leak source is the instrument used by the air compressor to provide the pipeline for stamping, the first punch 0.30bar (~ 0.03MPa), check the pipeline leak was found with 20 or so, leak-point concentrated in the welding sewing and pipeline at the interface with the parent material, and some leakage is the base metal zone, and some leakage to install welding point, the pressure relief through the installation of the company after the treatment; the second boost to the 0.50bar (~ 0.05MPa) test pressure leak, a total of 50 found leakage, leakage points, concentrated in one-inch tubes, the pressure relief, Trapping; the third boost to 0.60bar (~ 0.06MPa) leak detection, leak found a total of 20 points, relief Trapping; of the Fourth boost to 1.00bar (~ 0.1MPa) leak, this time on the tower and the argon system is a focus on examination of a place, and found that liquid argon is a leak near the pump the hardest hit, with 11 missing points , and the inch of lead leaching tube leak is relatively large, this uncovered a total of 35 leakage, pressure relief after the Trap; fifth boost, the boost to the tower 1.00bar (~ 0.1MPa), under the tower Boost to 3.00bar (~ 0.3MPa) leak, this leak were found 22, missed spots for the next tower, and many of which are leaking, need to wait 56 minutes in order to find relief Trapping; 6th second boost, on the tower to the 1.00bar (~ 0.1MPa), under the tower to the 5.00bar (~ 0.5NIPa) leak detection, leak-point decrease compared to the last, for 18 times, not because of aluminum-magnesium welding is very experience, some leakage points are repeated Trapping, finally became a riveting, by mutual consultation, our side does not allow riveting; the seventh step, on the tower to the 1.00bar (~ 0.1MPa) under the tower to the 6.00bar (~ 0.6MPa) leak detection, leak in front of Trap 11 is basically a place to live had not been filled, stress-relief treatment; step-up, on the eighth tower 1.00bar (~ 0.1MPa), under the tower 6.00bar (~ 0.6MPa ) leak detection, leak detected a total of 5 points, pressure relief Trapping; rest of the medium-pressure expansion of the air, high-pressure air, high-pressure oxygen, high-pressure nitrogen, argon between the pump outlet to the LV01602 pipeline through the red bottles of liquid nitrogen pump 01P805 Press , respectively, stamping to 44bar (~ 4.4MPa), 80bar (~ 8.0MPa), 59.5bar (~ 5.95MPa), 96.7bar (~ 9.67MPa), 11bar (~ 1.1MPa) leak point pressure test uncovered a total of 5, relief Trap; So far in this cold box leak leak detected a total of 186 points, eliminating leakage 186, cold box of the high and low voltage plate heat exchangers, on the tower, the next tower and argon search process piping systems connected to the initial end of the leak.

1.2 Cold-box pipeline by the force of the inspection

(1) pipeline hoop: hoop cold box and piping required to bear in the free state and asked for uniform force to prevent the pipeline shaking, with particular attention to a fixed valves, steel and aluminum joints hoop must To Hugging, in the inspection were found to have gaps, we must use hemp and PTFE plates to eliminate.

(2) pipeline Bracket: When the pipeline and out of equipment, such as the cooling device of the holder of import and export pipelines and pipelines with clearance can not require bracket force, and a larger gap can use hemp or PTFE plate pad in the middle. Should also be noted that if some of stent surface force is too small, there is likely to slide in the normal brackets, with the Hang oxygen contacts the edge of Canadian Shield in the bracket.
(3) block block: block block is part of the pipeline set up by gravity, and its role is to stop the valve near the pipeline in the hoop is still shaking after the cards of the general increase before and after the two.

1.3 Scaffold Inspection

Some manufacturers in order to facilitate future maintenance, cold-box scaffolding is not split, but in order to ensure the safety of equipment and pipelines, scaffolding and equipment, the distance between the pipe requires more than 300mm and can not be affected because of the scaffolding and equipment, pipelines force , grinding thin aluminum pipe; and carbon steel scaffolding in the cold arising under the easy fracture of brittle, so this part of the inspection must be careful.

Check the valve sleeve 1.4

A total lack of the cold box by checking the valve sleeve 7 (PV01609, V01511A, V01511B, HV01401, HV01504, HV0506, V01604), which PV01609, V01511A, V01511B, HV01401 4 valve stem has a circular sets out the cold box frame , can increase the valve sleeve, V01604, HV01504, HV01506 valve is to die in the cold box board, sleeve and valve design in conflict. Cold box valve sleeve is best not to leave all the cracks, to prevent the escape of pearlescent sand, and asked to use insulation sleeve cotton plug JANSEN, to prevent the moist air into the cold damage increase.
1.5 Equipment checks lycra
Under the main tower in the cold, crude argon column Ⅱ will shrink down to about 300mm, so the main tower, the crude argon column Ⅱ in the top of the tower's lycra require a fixed nut loose 10 ~ 20mm.

1.6 Electric heating block checks

Our low-temperature liquid-phase measurements are heated electrically charged pieces are LT01512, LT01501, LT01502, LT01601, LT01602, LT01606, LT01607, LT01608 a total of 13, in the cold box loaded perlite prior to heating block power to inspect whether the tubes and found that there is a LT01602 wiring problem, until after the installation of treated perlite.

1.7 Pipeline and cold box large seam inspection plate

Cold cold box by isolated case and the request is to prevent another string of pearlescent sand, but by pipeline with the cold box board request is seamless, in order to prevent frozen and cold box board, reducing cold damage, the pipeline with the cold box board space by Canadian casing set aside space 2 ~ 3cm, then hemp rope, PTFE sheet, glass wool plug JANSEN.

Two cold-box peripheral installation problems
2.1 Import and Export Pipeline Expansion Unit Installation

Expander, before and after the supercharger installation does not affect the force bearing expander. Installation of import and export pipeline, due to lack of experience to install, after installing the supercharger side lines, from the expansion of machinery exports to the impeller plate car plate does not move, indicating that import and export pipeline booster machines installed after the shell, the bearings have the role of force Later, after the release to the free state, in a free state, the compact flanges, expansion of client pipeline installation as well. And the expansion-side expansion joint must have a siemens stent hoop and no less, or expansion into the port-side flange will be subject to force seriously affect the freedom of the state expander.

2.2 The filter checks
Filters found in the inspection equipment expander entrance filter, pressure filter entrance plane accident nitrogen Pump Inlet filters have holes that filter does not keep well.

2.3 The high-pressure air throttling refrigeration valve

Pressure test valve HV01401 found in the membrane head Shouli Bu enough, resulting in HV01401 pressure> 50bar (~ 5.0MPa) when the closed die, and with the increasing amount of pressure and leakage.

2.4 The on-site installation of orifice flow
On-site installation requires a process flow orifice had confirmed the flow of process fluids to prevent anti-orifice installed, pay attention to the first hole, big hole in the post. There are cushions flow orifice flange installation, must be carefully selected.

2.5 low-temperature water pump filter

The network often led to pump gasification plug is damaged, mainly due to blocked filters mounted polypropylene packing and failed to note that the bag mouth Suimo fall into the water tower and into the pump. There is a certain level should pay attention to cooling tower, you can not pull the empty liquid pump damage.

2.6 molecular sieve regeneration of pipeline

The pipeline thermal expansion and contraction of the concrete supports have been damaged, and is ready designed spring-support; there is regeneration of nitrogen pollution shorting position is too low and too close to the control room from the compression, unsafe, so I will be shorting increased 4m, and to remove the rain to run into less resistance to bending.

3 Bare Cold Note

(1) bare cold-start equipment, and pipelines is not easy to frost, find the reasons climate in the north found that one dry, low water content in the air, so not easy to frost; second is too JANSEN manhole seal, air can not enter the cold box can not be in circulation, affecting the internal frost cold box. Later, some people hole opened Xiaofeng, valve cover to open, increasing the air humidity inside the cold.

(2) on the bare cold (cold state) leak, the control valve seat flange bolts, flow orifice flange bolts, thermometers nuts, valve import and export hoop, hoop steel and aluminum joints should be re-tight. Because the device pipeline are working under cold, while in hot tight under the flange, bolts, need a cold to bear.

(3) The venting valve UV01434, after the bare cold pressurized leak detection, as a result was the installation of the silencer muffler 01X403 film, but also because of instrumentation companies ESD interlocking system reload, the next full-tower venting valve UV01434 sudden, Under the column of air directly into the muffler 01X403, construction and installation of officers will be blowing down from the shelf, while not causing harm, but do analysis point of view, silencer 01X403 silencer was installed film, venting valve UV01434 should be crushed by hand wheel from the master to monitor the system pressure and to avoid causing an accident.

In short, the air separation unit during the installation process in strict accordance with installation and construction standards, strict control, especially in the construction of the cold box to require each and every device, every pipe, every valve, and each weld is sure.