Layout requirements for common equipment in chemical plants (below)

21 What are the specific requirements for tower side piping design?
(1) tower side piping generally have reflux, feed, side line extraction, steam extraction steam, reboiler inlet and return piping, etc., in order to make the valve closed without accumulation of liquid, the valves on the above piping should be directly connected directly with the tower body orifices, inlet (outlet) feeding pipe

Inlet (outlet) material piping at the same angle there are more than two inlet (outlet) material openings, the pipeline should consider a certain degree of flexibility;

(2) fractional Distillation Tower side line to the steam tower pipeline, such as regulating valves should be installed close to the steam tower. To ensure that the regulation of the same with a section of liquid in front of the residence. The height of the liquid column should meet the requirements of the process.
22 tower bottom piping design features?



(1) the bottom of the tower operating temperature is generally high, so in the arrangement of the bottom of the tower pipeline, its flexibility should meet the requirements of the relevant standards or codes. In particular, the bottom of the tower pumping pipeline and the pump is connected, the pipe should be short and less bends, and need to have enough flexibility to reduce the pump nozzle force.

Less pump nozzle force.

Tower bottom pumping line should be led to the tower skirt or outside the base, tower skirt is strictly prohibited to set the flange into the instrument fittings and other fittings. The bottom of the tower to the bottom of the pump pumping pipe in the horizontal pipe section shall not have a "bag shape", should be "step by step low", so as to avoid the bottom of the tower pump to produce cavitation phenomenon, the bottom of the pump.

The isolation valve on the pumping pipe should be as close as possible to the tower, and easy to operate.

(2) Unless it is an auxiliary reboiler, or two or more parallel reboilers operating at the same time, and the requirements of a wider range of regulation of its heat load, the bottom of the tower to the reboiler pipeline is generally not suitable for the installation of valves.

Tower bottom kettle type reboiler with a centrifugal pump, the elevation of the reboiler should meet the centrifugal pump required by the effective corrosion allowance, while making the tower bottom liquid level and the reboiler liquid level of the difference in the formation of the static head of pressure is sufficient to overcome the pressure of the descending liquid pipe, reboiler and ascending tube pressure

Losses. Therefore, the piping arrangement should meet the flexibility requirements at the same time, the piping should be short, the elbow should be less.



23 What requirements should be met for the arrangement of manholes on the tower?



(1) The manhole of the tower should be located in the operating area of the tower, where it is more convenient, safe and reasonable to enter and exit the tower, and should be located in the same orientation.

(2) Set up the manhole must pay attention to the internal components of the tower, generally should be located in the tower plate above the bubble area, shall not be located in the tower of the liquid drop tube or liquid tank area;

(3) Manhole (or hand hole) on the tower, generally every 3-8 layers of tower plate layout;

(4) The height of the manhole center from the platform surface is generally between 600mm and 1000mm, the most suitable height of 750mm;

(5) A tower on the manhole should be arranged in the same vertical line, so that it is neat and beautiful.


24 tower orifice orientation requirements?



(1) tower orifice orientation should meet the working principle of the tower parts and structural requirements, the design should pay attention to the overall structure of the equipment components and the relative orientation of the orifice; tower top gas-phase openings are arranged in the middle of the tower top header; tower reflux openings, generally arranged in the tower plate

Piping side of the upper; gas-phase feed openings in the tower above the plate, parallel to the liquid-reducing pipe; gas-liquid mixed-phase feed openings in the tower above the plate, and set up a distribution pipe; vapor steam openings in the lower part of the vapor tower plate, and add a gas distribution pipe.

Side line product extraction outlet in the liquid drop tube below the common arc range, it is appropriate to set up the extraction bucket, for the middle liquid drop tube of the double overflow tower plate, the extraction outlet can be arranged in the place at any angle, set up the extraction bucket; the bottom of the tower extraction outlet is located in the middle of the tower bottom header cover, and set up to prevent the

Vortex plate, the pumping outlet should be extended to the skirt of the tower outside.

(2) For the tower with tower plate, the manhole should be arranged in the tower diameter parallel to the overflow weir of the tower plate, or not parallel when conditions do not allow, but the net distance between the manhole and the overflow weir in the horizontal direction should be not more than 50mm.

(3) The orientation of the manhole lifting, and the setting of the ladder should be uniformly arranged, and in case of accident, the direction of smooth closing of the man cover and the direction of evacuation of people should be the same.
(4) The level meter interface can be directly connected to the level meter through the root valve or connected to the level meter connecting pipe through the root valve. The level meter interface shall not be arranged within a 60° angle opposite the inlet, unless the inlet is protected by an internal baffle.

External float level control tubes connected directly to the tower shall be baffled. Liquid level meter, level control float, alarm and other devices are often located in the tower platform or localized platform end, in order to facilitate maintenance.

(5) The manometer interface should be arranged in the gas phase area of the tower, so that the manometer reading is not affected by the liquid level pressure head.

(6) Sampling port and temperature measurement port arrangement, gas phase sampling port and temperature measurement port should avoid the gas phase area of the tower plate drop tank, liquid phase sampling port and temperature measurement port should be located in the drop tube area of the tower plate within the liquid holding layer; for easy crystallization of the liquid phase sampling tube should be to the tower plate.

(7) Positioning of the column at the top of the tower should be such that it can reach the top of the lifting point outside the platform when rotating, as well as the position of all the holes in the platform.

25 What orientation should an equipment orifice orientation diagram indicate in addition to the orifice?



In addition to indicating the process and utility media pipe openings, it should also indicate:

(1) the orientation of the instrumentation receiver, including temperature, pressure, liquid level;

(2) Manhole, hand hole and the orientation of the column, the orientation of the skirt exhaust hole;

(3) The orientation of the equipment ground bolt holes or the orientation of the support lugs;

(4) The location of lugs, ground plates and nameplates;

(5) The orientation of the internal ladder, the bottom of the skirt to strengthen the support.



26 How to determine the fixed side of the horizontal container support?



Identify the most important (difficult or demanding) one pipe for flexibility calculation from the pipes to be connected to this vessel, such as the pipe with large compensation volume and pipe diameter, as the basis for deciding the type of support. The position of the fixed side support should be favorable to the pipe

Flexibility calculation.



27 What are the requirements for orifice orientation of horizontal vessels?



(1) Liquid inlets and outlets on the equipment shell should be spaced as far apart as possible. The liquid inlet pipe should be located as far away from the vessel level gauge connection as possible;

(2) The liquid level meter interface should be arranged in the position where the operator can easily observe and conveniently maintain the misery. Sometimes in order to reduce the receiver port on the equipment, in situ liquid level meter, liquid level controller, liquid level alarm and other measuring devices can be installed on the joint box. Wave level meter pipe

Position, should be arranged with the level control valve group on the same side;

(3) The manhole cover connected by hinge (or lifting post) should not affect other pipe openings or pipelines when opened;

(4) The safety valve receiver port should be located at the top of the vessel.



28 What are the general requirements for piping arrangement of horizontal vessels?



The piping of the container (tank) is relatively simple; the piping arrangement of the vertical container is generally similar to the piping arrangement of the tower, and also takes the design along the wall of the tank, and the valves on the piping are also required to be directly connected to the opening; this can avoid the accumulation of liquid.

Horizontal container equipment arrangement, generally the long direction of the tank and the corridor is perpendicular so its piping, such as gas outlet piping, safety valve outlet piping, liquid outlet piping, etc., are oriented towards the corridor, and the corridor on the relevant; connected to the main pipe.
The elevation of the piping connected to the opening at the top of the vessel should be higher than that of the main pipe connected to the corridor so that it can be connected to the top of the main pipe. When the liquid outlet pipe at the bottom of the container is connected to the pump under the pipe, the elevation of the bottom of the pipe should not affect the passage of people.

(1) For piping connecting the liquid outlet of the horizontal container with the suction port of the pump, the minimum headroom is 2200mrn if the piping is overhead on the passage;

(2) For piping connected to the bottom orifice of the horizontal container, the minimum headroom of the liquid discharge outlet from the floor at its low point is 150mm;

(3) safety valve outlet discharge into the closed piping system, should avoid the accumulation of liquid, and to meet the safety valve outlet piping along the medium flow direction into 45 ° down to the top of the closed pipe connected to the main, and no "pocket". If the safety valve is installed away from the vessel, check the pressure from the vessel to the safety valve inlet pipe.

vessel to the safety valve inlet piping pressure drop;

(4) The regulating valve group of the pipeline on the top of the storage tank is arranged on the platform;

(5) The platform should be set up according to the inert condition of equipment and piping arrangement.



29 heating furnace piping layout design of the general requirements?



(1) heating furnace piping arrangement with the heating furnace type is different, in the heating furnace piping arrangement, should be inlet and outlet piping, fuel system piping, soot blowing gas piping, fire extinguishing steam piping and other unified consideration;

(2) for the cylinder furnace inlet and outlet pipe, usually ring-shaped arrangement around the furnace body, can be supported on the ground or the furnace body. The ring-shaped main pipe should be arranged above the watchman's door so as to facilitate the normal operation and maintenance of the watchman's door;

(3) If necessary, in the furnace outlet pipe elbow. Tee or reducer larger than the other, or from the top of the furnace vertically down to the bottom of the position, the installation of anti-vibration mounts;

(4) If rupture discs are provided in the piping, they must not be oriented toward the operation or equipment;

(5) The main regulating valve group is usually arranged between the pipe gallery and the furnace body and pay attention to the access requirements;

(6) Valves on steam, fuel oil, or fuel gas piping should be arranged on vertical piping near the watchdog door and meet the requirements for regulation and maintenance;

(7) In cold areas, steam tracing shall be used for fuel oil piping in accordance with regulations;

(8) The pipeline near the nozzle should adopt the connecting structure which is easy to dismantle for cleaning and maintenance;

(9) Platforms and ladders shall be provided at frequently operated valves and observation areas at higher locations;

(10) The discharge point of the fuel pipeline should be at least 15m above the furnace and should be discharged into the collection system, not directly into the sewer;

(11) Pipes connected to the furnace, as far as possible, centrally arranged for support, to achieve coordination. The purpose of aesthetics;

(12) For the feeding pipeline of the heating furnace, the flow rate of each road should be kept uniform; for the all-liquid-phase feeding pipeline, generally each road is equipped with a flow control valve to regulate the flow rate of each road, or else the pipeline should be symmetrically arranged, and the inlet and outlet pipelines of the gas and liquid phases must be used in a symmetrical

Arrangement to ensure that the pressure drop in each way is the same;

(13) annular oil line should be the highest temperature calculation of thermal compensation, and the use of pipeline natural compensation to absorb its thermal expansion.
30 What are the general requirements for the fuel gas piping arrangement of the heating furnace?



(1) Fuel gas should be set up to distribute the main pipe, so that the fuel gas of each nozzle can be evenly distributed; the fuel gas branch pipe is led out from the upper part of the distribution main pipe, so as to ensure that the fuel gas into the nozzle does not carry water or condensed oil.
At the end of the fuel gas distribution head is equipped with a DN20 drain valve, which is convenient for the test run flushing and shutdown sweeping line after the liquid discharge, as well as the start of sampling to analyze the oxygen content in the pipeline, the liquid discharge pipe should be equipped with two liquid discharge valves to avoid leakage, the valve can be on the ground or on the platform.

The valve can be operated on the ground or platform. Fuel gas shut-off valve should be located 15m away from the heating furnace.

(2) in the fuel gas pipeline to set the flame arrestor, you can prevent the flame spread, flame arrestor according to the principle of action can be divided into dry flame arrestor and safety water seal two kinds. Industrial production facilities in the heating furnace on the fuel gas pipe generally use multi-layer copper wire mesh dry flame arrestor.

Flame arrestor. The flame arrestor should be placed close to the nozzle. Pipe flame arrestor and burner distance should not be greater than 12 m. In this way, the flame arrestor will not be in a serious burst zha conditions, life can be extended.



31 shell and casing type heat transfer equipment piping arrangement should be considered?



(1) process piping arrangement should pay attention to the cold, hot logistics flow direction, the general cold flow from bottom to top, hot flow from top to bottom;

(2) The piping arrangement should be convenient for operation, and does not hinder the maintenance of the equipment;

(3) The elevation of the foundation of the heat transfer equipment should meet the lower drain pipe from the ground or platform surface is not less than 150mm;

(4) heat transfer equipment pipeline, there can only be a high point and a low point, to avoid the middle of the "gas bag" or "liquid bag", and set up a high point of emptying, low point of the net; in the heat transfer equipment should be avoided as far as possible within the region of pipeline crossings and bypasses; try to minimize the pipeline

The number of layers of overhead piping, generally 2-3 layers;

(5) two or more than two parallel heat transfer equipment inlet pipe straight symmetrical arrangement, the gas-liquid two-phase flow heat transfer equipment must be symmetrically arranged in order to achieve good heat transfer;

(6) heat transfer equipment, measuring instruments on the import and export piping, should be installed near the operating channel and easy to observe and overhaul;

(7) and the heat transfer equipment connected to the easy to condense medium of the pipeline or pipeline containing solid particles of the sub-line, the shut-off valve should be located in the horizontal pipeline, and should prevent the formation of dead-end accumulation of liquid;

(8) in cold areas, outdoor heat exchanger equipment on the upper and upper water piping should be provided with a drain valve and anti-freeze connecting pipe.



32 arranged in groups of heat transfer equipment and its piping arrangement should be designed?



(1) group arrangement of heat transfer equipment in the area, can be laid on the ground or platform piping, but should not interfere with access and operation;

(2) When there is no regulating valve or drain pipe on the pipeline, the clearance from the bottom of the pipe to the ground should be greater than or equal to 150mm;

(3) The regulating valve group should be arranged parallel to the cold exchange equipment.

(4) The net distance of piping arrangement between heat exchanging equipments arranged in groups should be greater than or equal to 650mm;

(5) Piping arrangement should be considered for each heat exchanger equipment pipe box and header cover disassembly space;

(6) The import and export piping of heat exchanger equipment connected in parallel should be arranged symmetrically.



33 vertical reboiler piping arrangement requirements?



(1) The piping must be flexible enough to compensate for the thermal expansion of the equipment and piping under various operating conditions;

(2) When the heavy boiler pipe port and the tower of the pipe port butt, if the load conditions allow, it is best to set up a tower support heavy boiler bracket, and the location and form of the bracket should be able to meet the tower and pipeline expansion of the displacement and loading requirements;
(3) When piping, the space required for dismantling the heavy boiling pipe bundle in situ should be left;

(4) For single-pass fixed-tube plate heat exchanger with expansion joints on the shell, the influence of such expansion joints should be considered when piping, flexibility analysis and support design of equipment are carried out;
(5) When the length to diameter ratio (L/D) of the reboiler is greater than 6.0, it is desirable to have guided supports;

(6) When the valves and blinds of the reboiler are assessed to be more than 3m above the ground, a platform should be provided on the tower.



34 shell and tube horizontal horizontal reboiler piping arrangement requirements?



(1) in the thermal expansion of the permissible stress range, heavy boiler drop liquid pipe and steam pipe, should try to resist short and straight, reduce the number of elbows to reduce the pressure drop;

(2) when the heavy boiler has two steam rising mouth, in order to make its tube flow green equal, steam rising province should be symmetrically arranged. If the rising steam pipe diameter and arrangement of different asymmetric, should try to make the resistance of the two pipe sections are equal. Otherwise, the flow rate of the rising steam pipe with large resistance is small.

Will make the heat distribution is not uniform;

(3) from the reboiler pumped out of the liquid for the saturated liquid, if the piping system produces a pressure drop, the liquid will begin to flash, resulting in gas-liquid two-phase fluid flow, affecting the operation and accuracy of the control and measurement instruments. Therefore, when arranging the saturated liquid pipeline

The basic principle is to minimize the pressure drop, and in the measurement or control instrumentation does not appear before the vertical rise of the pipe section;

(4) reboiler piping heating medium inlet piping is usually equipped with temperature control valve and its valve group, these valves are generally arranged near the reboiler piping inlet ground or platform surface.



35 What are the specific requirements for piping design of air coolers?



(1) Fractionator top to the air cooler oil and gas piping, generally should not appear "liquid pockets". When the air cooler import and export no valve or two-phase flow, the pipeline must be symmetrically arranged, so that the flow of each piece of air cooler uniform;

(2) The inlet pipe of the air cooler should be connected close to the nozzle of the air cooler; if necessary due to stress or installation, the outlet pipe may not be connected close to the nozzle, and the cross-sectional area of the pipe should be larger than the sum of the cross-sectional areas of the branch pipes;

(3) When the population of the air cooler is gas-liquid two-phase flow, each branch pipe should be inserted into the population collection pipe from below; in order to make the fluid distribution at the bottom of the collection pipe uniform; at the same time, a shutdown discharge pipe is set below the collection pipe and connected to the outlet pipe of the air cooler;

(4) The population pipe of the air cooler is high; if the distance is long, it is necessary to set up a special pipe rack in the middle to support the pipe;

(5) The softened water return system of wet air cooler is self-flowing pipeline, therefore, attention should be paid to the arrangement of the pipeline system and the bends should not be too many. The return water main pipe should have a slope in the direction of media flow;

(6) air cooler operating platform with semi-fixed steam blowing joints, the valve should be located in easy access, and should pay attention to the direction of the steam joints to ensure safe operation.
36 pump piping design general requirements?



(l) pump inlet and outlet piping should be set up to cut off the network, the pipeline must be flexible enough to reduce the piping role in the pump pipe mouth of the stress and moment;

(2) pump suction piping should meet the pump's "cavitation margin" requirements, the pipeline should be as short as possible, fewer bends should not have air pockets. If it is difficult to avoid, should be set at the high point of the bleeder valve;

(3) When the pump suction pipe is long, it is appropriate to design a certain slope (i = 5 ‰); pump than the container is appropriate to slope to the pump, the pump is appropriate to slope to the container than the container is appropriate to slope to the container;

(4) In the pump population immediately downstream of the pipeline shut-off valve, there should be a filter or temporary filter, in order to prevent the pump fluid backflow caused by the pump impeller reversal, the pump outlet should be equipped with a check valve;
(5) Under the premise of meeting the process requirements, the pump piping. Valve handwheel shall not affect the normal operation of the pump and the space required for maintenance and inspection;

(6) Reciprocating pump inlet and outlet piping design should take into account the impact of fluid pulsation.



37 What are the types of pump protection lines? What is its role?



There are six kinds of pump protection lines, the role of which is to make the pump body is not damaged and normal operation, according to the conditions of use to set the pump protection line.
(1) Warm pump line - in the transport medium temperature greater than 200 ℃ high temperature oil, there is a backup pump should be set DN20 ~ 25 warm pump line;

(2) small flow line - when the working flow of the pump is less than 30% of the rated flow of the pump, the pump should be set up in the lowest flow rate of normal operation of the small flow line;

(3) balance line - for the delivery of room temperature saturated vapor pressure higher than the atmospheric pressure of the liquid or in the bubble point state of the liquid, in order to prevent the liquid into the pump to produce steam or bubbles into the pump should be added to balance the line caused by cavitation;

(4) Bypass line - used for pump test run or non-normal operation of the state of the outlet valve is closed, can still make the pump in operation. Generally in the valve before and after the very high pressure difference between the occasions set with a limited flow orifice pole bypass valve;

(5) Anti-coagulation line - conveying at room temperature solidification of the high pour point or high solidification point of the liquid, its standby pumps and pipelines should be set up anti-coagulation line, so as to avoid clogging of the standby pumps and pipelines;

(6) safety valve line - for electric reciprocating pumps, gear pumps and screw pumps and other displacement pumps, the outlet side of the safety valve line, when the outlet pressure exceeds the fixed pressure value, the safety valve jumps, the fluid returns to the pump population tube.



38 centrifugal compressor piping arrangement of the general requirements?



(1) Centrifugal compressor shell has two forms: vertical split type for high-pressure, there shall be no pipelines and other obstacles in front of the machine; horizontal split type for medium and low pressure, there shall be no pipelines and other obstacles on the upper part of the machine;
(2) The arrangement of the import and export pipelines should minimize the number of elbows to reduce the pressure drop under the conditions of thermal compensation and allowable stress;

(3) The inlet and outlet pipe nozzles are generally facing downward, supported by the center of the machine shell, and their thermal expansion should be absorbed by the pipes during operation;

(4) plant set up in the compressor nozzle for the upper inlet and outlet, in its inlet and outlet nozzle pipeline shall be set up removable short section, so that the compressor overhaul.



39 reciprocating compressor piping design of the general points?



(1) compressor import and export piping arrangement should be short and straight, minimize the number of elbows, but the export pipeline has thermal expansion, the pipeline should be flexible;

(2) The pipeline arrangement should consider the self-flow of liquid to the liquid separation tank, when the pipeline appears "liquid bag", there should be a low point of discharge;
(3) multiple units side-by-side arrangement, its inlet and outlet pipeline valves and instruments should be arranged in an easy to operate, easily accessible place;

(4) In order to prevent the compressor import and export pipeline vibration, the necessary vibration analysis should be carried out. Piping arrangement should be as low as possible, the bracket is laid on the ground, and for the independent foundation, increase the rigidity of the bracket and pipeline;

(5) compressor medium for combustible gases, pipeline low-point Ran condensation, high-point venting valves should be set up silk plug, pipe cap or flange cover to prevent leakage, and the unit around the pipe trench should be filled with sand to avoid the accumulation of combustible gases;
(6) the arrangement of compressor import and export pipeline, should not affect the maintenance crane walking;

(7) The compressor pipeline should be arranged under the operating platform, so that there is a more spacious operation and maintenance space around the unit.


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