|
US$2119.00 · In stock
Delivery: <= 13 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB 50648-2011: Code for design of recirculating cooling water system in chemical plant
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB 50648-2011 | English | 2119 |
Add to Cart
|
13 days [Need to translate]
|
Code for design of recirculating cooling water system in chemical plant
| Valid |
GB 50648-2011
|
PDF similar to GB 50648-2011
Basic data | Standard ID | GB 50648-2011 (GB50648-2011) | | Description (Translated English) | Code for design of recirculating cooling water system in chemical plant | | Sector / Industry | National Standard | | Classification of Chinese Standard | P72 | | Classification of International Standard | 71.010 | | Word Count Estimation | 96,924 | | Date of Issue | 2010-12-24 | | Date of Implementation | 2011-12-01 | | Quoted Standard | GB 50050; GB 50013; GBJ 87 | | Regulation (derived from) | Ministry of Housing and Urban Notice No. 878 | | Issuing agency(ies) | Ministry of Housing and Urban-Rural Development of the People's Republic of China; General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China | | Summary | This Chinese standard applies to new construction, expansion, renovation projects in chemical engineering circulating cooling water systems engineering design. | GB 50648-2011: Code for design of recirculating cooling water system in chemical plant---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
1 General
1.0.1 In order to make the design of the circulating cooling water system in the chemical industry comply with national guidelines, policies, laws and regulations, unify the technical requirements for system design, achieve safety, reliability, advanced technology, reasonable economy, convenient management, and maintenance, and meet water-saving requirements, energy saving and environmental protection, labor safety and sanitation protection and other requirements, formulate this specification.
1.0.2 This code is applicable to the design of circulating cooling water system engineering of new construction, expansion and reconstruction of chemical engineering projects.
1.0.3 The design of the circulating cooling water system in the chemical industry should actively and steadily adopt effective new processes, new technologies, new equipment and new materials on the basis of continuously absorbing domestic and foreign advanced technologies, summarizing production practice experience and scientific experiments.
1.0.4 The design of the chemical industry circulating cooling water system project shall not only implement this specification, but also comply with the current relevant national standards.
2 terms
2.0.1 recirculating cooling water system
A water supply system that uses water as the cooling medium and circulates, consisting of heat exchange equipment, cooling facilities (equipment), treatment facilities, water pumps, pipelines and other related facilities.
2.0.2 indirect open recirculating cooling water system indirect open recirculating cooling water system
A circulating cooling water system in which the circulating cooling water and the cooled medium indirectly transfer heat and the circulating cooling water directly contacts the atmosphere to dissipate heat.
2.0.3 Indirect closed recirculating cooling water system indirect closed recirculating cooling water system
Circulating cooling water and cooling medium indirect heat transfer and circulating cooling water and cooling medium are also indirect heat transfer circulating cooling water system.
2.0.4 direct open recirculating cooling water system
The circulating cooling water system is a circulating cooling water system in which the circulating cooling water is in direct contact with the cooled medium to exchange heat and the circulating cooling water is in direct contact with the atmosphere to dissipate heat.
2.0.5 secondary water secondary water
After the first use, the water quality can meet the water reuse without treatment.
2.0.6 wet cooling tower wet cooling tower
A cooling tower in which water and air are in direct contact, and heat and mass exchange are performed simultaneously to lower the water temperature.
2.0.7 dry-wet cooling tower
A cooling tower that combines the functions of air cooling and wet cooling towers.
2.0.8 natural draft cooling tower natural draft cooling tower
The cooling tower that provides the air flow power in the tower by the draft force formed by the difference in air density inside and outside the tower.
2.0.9 Mechanical ventilation cooling tower
The power of the air flow in the tower is the cooling tower provided by the ventilation machinery (fan).
2.0.10 counter-flow cooling tower
The air enters the tower from the air inlet at the lower part of the tower, and exchanges heat with the water flowing from the upper part of the tower to reduce the water temperature.
2.0.11 Cross-flow cooling tower cross-flow cooling tower
The air enters the tower horizontally from the air inlet of the tower, and passes through the packing perpendicular to the water flow direction to reduce the water temperature of the cooling tower.
2.0.12 Water spray packing
It is installed in the cooling tower, so that there is sufficient contact time and area between water and air, which is conducive to the filling material of heat and mass exchange.
2.0.13 net area of water drenching
The cross-sectional area of the beam and column area deducted from the top of the cooling tower spray fill.
2.0.14 water eliminator drift eliminator
It is a device installed in the cooling tower to recover the liquid water (water droplets, water mist) entrained in the tower airflow.
3 circulating cooling water system
3.1 General provisions
3.1.1 The design of the circulating cooling water system shall include the division of the system and the layout of the circulating cooling water device area, the design of the circulating water cooling facilities, the design of the circulating cooling water water quality treatment, the design of the circulating cooling water pumping station, the design of the water transmission and distribution pipe network and the design of supporting facilities.
3.1.2 The design of the circulating cooling water system should be based on the water balance plan of the whole plant, making full use of reclaimed water and reducing the consumption of water resources.
3.1.3 The design of circulating cooling water system shall meet the following requirements.
1 It shall meet the requirements of the heat exchange working condition of the production device;
2 For process heat exchange equipment with large differences in water temperature, water quality or water pressure requirements, circulating cooling water systems should be installed separately; for individual heat exchange equipment with high water pressure requirements, local pressure boosting measures should be adopted;
3 The production process requires that the devices or units that cannot interrupt the circulating cooling water supply shall have safe water supply guarantee measures.
3.1.4 The design water volume of the circulating cooling water system shall be calculated according to the normal hourly water consumption of process production equipment and auxiliary production equipment, and shall be checked by the maximum hourly water consumption.
3.1.5 The design water supply temperature of the indirect cooling open type and direct cooling open type circulating cooling water system shall be determined by thermodynamic calculation according to the water supply temperature allowed by the production process and combined with the meteorological conditions of the plant construction area.
3.1.6 The water supply temperature of the intercooled closed circulation cooling water shall be determined according to the requirements of the production process and combined with the temperature of the cooling medium.
3.1.7 The expansion tank of the intercooled closed system shall have functions such as nitrogen automatic pressure regulation, water level detection, automatic water replenishment and discharge, and prevention of air entering the system.
3.1.8 The pressure of the return water of the intercooled open circulating cooling water system should be fully utilized.
3.1.9 The collecting pool and suction pool under the cooling tower of the circulating cooling water system should not be used as a fire fighting pool.
3.2 Basic information
3.2.1 The multi-year meteorological statistical data of the plant construction area or adjacent areas selected for the design of the circulating cooling water system shall meet the following requirements.
1 Meteorological data such as dry and wet bulb temperature and atmospheric pressure should be calculated based on the daily average wet bulb temperature, and the average number of hottest days in the hottest period in the past five years in the factory area should not exceed 5d-10d. The daily average wet-bulb temperature shall be used as the design wet-bulb temperature, and the corresponding daily average dry-bulb temperature and atmospheric pressure shall be used as the design dry-bulb temperature and atmospheric pressure;
2 For the dust content data in the atmosphere, the average value of the maximum daily dust content in the past 5 years should be used as the design basic data;
3 It is advisable to use the wind direction and wind frequency throughout the year as the basic data for design;
4 When the circulating cooling water device is located in the existing factory area or adjacent to other buildings (structures) and devices that may emit moisture and heat sources, attention should be paid to the influence of the surrounding environment on the circulating cooling water cooling facility;, attention should be paid to the influence of regional microclimate.
3.2.2 The data collection of the heat transfer conditions of the production process shall include the following contents.
1 The structural form and material of the heat exchanger;
2 The process medium and properties to be cooled;
3 Process operating conditions of the heat exchanger.
3.2.3 The supplementary water source and water quality data collection shall include the following contents.
1 The supply conditions of surface water, groundwater and available recycled water sources;
2 The surface water source should not be less than the monthly water quality analysis data of the past year;
3 The groundwater source should not be less than the quarterly water quality analysis data of the past year;
4 The reclaimed water source should not be less than the full water quality analysis data of the reclaimed water treatment system that has been running stably month by month for the past year.
3.2.4 The collection of basic data in the factory construction area shall include the following contents.
1 The types and supply conditions of biocides that can be used to control the reproduction of microorganisms in the factory construction area and surrounding areas;
2 Engineering geology, hydrogeology and other data of the plant construction area.
3.3 System division
3.3.1 The circulating cooling water system shall determine centralized or partitioned settings based on the following factors.
1 Requirements of the production process on the water quality, water quantity, water temperature and water pressure of circulating cooling water;
2 The plane position and elevation of each production device;
3 Requirements for the overall planning of the factory and phased construction;
4 Open and stop operation cycle.
3.3.2 The cooling water for indirect heat exchange with process materials in the production process should adopt an indirect open-type circulating cooling water system.
3.3.3 The process requires high heat transfer conditions, and the circulating cooling water system that requires demineralized water or desalinated water as the cooling medium should adopt an intercooled closed circulating cooling water system.
3.3.4 For the circulating cooling water that is in direct contact with the process materials and is polluted during the production process, an independent direct-cooling open-type circulating cooling water system should be set up.
3.3.5 When the supplementary water of the circulating cooling water system comes from various water sources and the water quality differs greatly, different circulating cooling water systems should be divided according to the water quality and water supply of the supplementary water source.
3.3.6 The scale of the intercooled open circulating cooling water system can be divided according to the following ranges.
1 When the system capacity is greater than or equal to 15000m3/h, it shall be large;
2 When the system capacity is greater than or equal to 3000m3/h and less than 15000m3/h, it shall be medium-sized;
3 When the system capacity is less than 3000m3/h, it shall be small.
3.4 Location selection
3.4.1 The position of the circulating cooling water device shall be determined by comprehensive comparison of the following factors.
1 Close to the main water use device or workshop of circulating cooling water;
2 Keep away from open-air heat sources, dust pollution sources, flue gas outlets, chemical storage yards, bulk warehouses and noise-sensitive areas in the factory;
3 The air flow is smooth, and the influence of hot and humid air backflow is small;
4 There are sufficient convenient conditions for site layout and development and expansion;
5 Engineering geological conditions of the site.
3.4.2 The circulating cooling water device should be built on the windward side of the annual minimum frequency wind direction adjacent to buildings (structures) and power transformation (distribution) devices.
3.4.3 The circulating cooling water device should be installed outside the explosion-proof area divided by the production equipment. When it is located in the explosion-proof area, the selection and installation design of its electrical and instrumentation equipment should comply with the relevant current national explosion-proof standards.
3.4.4 The intercooled closed circulating cooling water device should be arranged in the production process area, or it can be combined with the intercooled open circulating cooling water device.
3.5 Device layout
3.5.1 The layout of the circulating cooling water device shall make full use of the topography, and be reasonably arranged in consideration of factors such as the relationship between individual buildings (structures) and the integration of pipelines in the device.
3.5.2 Buildings (structures) such as substation (distribution) room, water quality treatment room, and chemical room in the circulating cooling water device should be adjacent to the pumping station.
3.5.3 Circuits, inspection and transportation passages should be set up between the buildings (structures) in the circulating cooling water device.
3.5.4 The ground around the buildings (structures) in the circulating cooling water device should be paved.
3.5.5 When the environmental conditions permit, the equipment and facilities such as the pumping station and side filter in the circulating cooling water device should be arranged in the open air.
3.5.6 For the open circulating cooling water system adopting gravity self-flow return water, the water suction pool of the hot water lift pump set and the water suction pool of the circulating feed water pump set should be arranged next to each other, and the top overflow connection should be provided.
3.5.7 The return water sedimentation treatment tank of the direct cooling open-type circulating cooling water system should be close to the production process area, and sediment removal facilities and temporary storage yards should be set up.
4 System water balance
4.1 General provisions
4.1.1 The circulating cooling water system should determine a reasonable concentration factor based on the supplementary water quality, circulating cooling water quality, and environmental requirements. The concentration factor of the intercooled open-type circulating cooling water system should not be less than 5.0, and should not be less than 3.0.
4.1.2 The circulating cooling water system shall carry out water balance calculation according to the design water volume and heat transfer conditions, regional meteorological conditions and concentration multiple, and shall determine the system's evaporation water loss, wind blowing water loss, sewage loss water loss and system replenishment water volume.
4.1.3 Under the conditions allowed by the production process, the intercooling circulating cooling water should be used in cascade.
4.2 Calculation of water balance
4.2.1 The evaporation loss of the intercooled open circulating cooling water system should be calculated according to the following formula.
4.2.2 The wind blowing water loss of the cooling tower should be calculated according to the following formula.
4.2.3 The sewage discharge volume of the intercooled open circulating cooling water system should be calculated according to the following formula.
4.2.4 The supplementary water volume of the intercooled open circulating cooling water system can be calculated according to the following formula.
4.2.5 The design concentration factor of the intercooled open circulating cooling water system can be calculated according to the following formula.
4.2.6 The supplementary water volume of the intercooled closed circulating cooling water system should be 1‰ of the circulating cooling water volume.
4.2.7 The sewage of the intercooled open circulating cooling water system should be controlled uniformly, and should be discharged in a concentrated manner in the area of the circulating cooling water device, and the total sewage volume should be controlled within the allowable sewage volume range of the circulating cooling water system.
4.3 Water quality balance
4.3.1 When it is necessary to remove suspended solids in the water during the operation of the intercooled open-type circulating cooling water system, side-flow filtration should be used, and the amount of side-filtration water can be calculated according to the following formula.
4.3.2 When the circulating cooling water system adopts side flow water treatment to remove alkalinity, hardness, certain ions or other impurities, the amount of side flow treatment water should be based on the concentrated or polluted water quality components, circulating cooling water water quality indicators and side flow treatment After the water quality requirements are determined, it can be calculated according to the following formula.
4.3.3 When multiple water sources are used as supplementary water or reclaimed water is used as supplementary water source, water quality balance calculation shall be carried out, the proportion of supplementary water from various water sources shall be reasonably allocated, and the corresponding concentration multiple shall be determined.
4.3.4 The direct-cooling open-type circulating cooling water system shall carry out water quality balance calculation according to the control requirements of the system water quality index, and shall determine a reasonable amount of discharged sewage and corresponding treatment measures.
4.4 System volume
4.4.1 The designed residence time of the intercooled open circulating cooling water system should not exceed the allowable residence time of the agent. The design residence time can be calculated as follows.
4.4.2 The volume of the intercooled open circulating cooling water system can be calculated according to the following formula.
4.4.3 The water volume of the intercooled closed circulation cooling water system can be calculated according to the following formula.
5 cooling facilities
5.1 General provisions
5.1.1 The capacity of the cooling facility should match the heat load required by the production unit, and it may not be used.
5.1.2 The thermodynamic calculation of the cooling tower should adopt the enthalpy difference method, and the segmental integral method can also be used.
5.1.3 The water spraying area of the cooling tower shall be the effective water spraying area of the filler.
5.1.4 The number of mechanical ventilation cooling towers should not be less than 2; the sump under the tower of multiple combined cooling towers should be combined with necessary separation measures for tower body maintenance, management, overhaul, etc.
5.1.5 The cooling facilities in dusty areas should be equipped with sand prevention and sand discharge measures.
5.1.6 The design of the cooling tower shall meet the requirements of operation, maintenance and safety protection.
5.1.7 Cooling towers in cold regions should be equipped with antifreeze facilities.
5.2 Selection of cooling facilities
5.2.1 The selection of cooling facilities should be determined according to the working conditions of the production unit and the local meteorological conditions. In the case of suitable weather conditions, other cooling facilities other than wet cooling towers can be used.
5.2.2 The selection of cooling tower tower type shall be determined through technical and economic comparison according to the water volume, water temperature, water quality of circulating cooling water and the operation mode of circulating cooling water system and other conditions, combined with the following factors.
1 Natural conditions such as local meteorology, topography and geology;
2 Availability of materials and equipment;
3 site layout and construction conditions;
4 Interaction between cooling tower and surrounding environment.
5.2.3 Cooling tower design Under the condition of cooling water supply temperature meeting the production process requirements, the tower type should meet the following requirements.
1 When the approach degree (t2－τ)≤4℃, counterflow mechanical ventilation cooling tower should be adopted;
2 When 4°C < approach degree (t2-τ) ≤ 5°C, cross-flow or counter-flow mechanical ventilation cooling towers can be used;
3 When the degree of approach (t2-τ) > 5°C, a natural draft cooling tower or a mechanical draft cooling tower can be used.
5.2.4 For direct cooling open-type circulating cooling water systems containing pollutants such as phenol and cyanide, the cooling facilities should adopt blower-type mechanical ventilation cooling towers or natural ventilation cooling towers; Water packing, water eliminator, etc. should be corrosion-resistant, anti-aging, anti-fouling and clogging.
5.2.5 For circulating cooling water systems that are easily polluted by flammable and combustible liquids or gases, the selection and installation of electrical and instrumentation equipment for mechanical ventilation cooling towers, as well as tower top lighting, should be designed according to the relevant current national explosion-proof standards.
5.2.6 When selecting a finished cooling tower, it should be selected according to the measured thermal characteristic curve of this type of product.
5.3 Arrangement of cooling facilities
5.3.1 The layout of the cooling tower shall meet the following requirements.
1 The distance between cooling towers or between cooling towers and other buildings (structures) shall not only meet the ventilation requirements of cooling towers, but also meet the requirements of construction and maintenance sites;
2 The air inlet surface of the mechanical ventilation cooling tower with one-sided air intake should face the dominant wind direction in summer; the air inlet surface of the mechanical ventilation cooling tower with double-sided air intake should be parallel to the prevailing wind direction in summer;
3 The clear distance between the cooling tower and other buildings (structures) shall not be less than twice the height of the air inlet of the cooling tower.
5.3.2 The clear distance between adjacent natural draft cooling towers shall meet the following requirements.
1 The counterflow natural ventilation cooling tower should be 0.45 to 0.5 times the tower diameter of the lower edge of the air inlet of the tower;
2 The cross-flow natural draft cooling tower shall not be less than 3 times the height of the air inlet of the tower;
3 When the geometric dimensions of two adjacent towers are different, it shall be calculated as the larger cooling tower.
5.3.3 There are many mechanical ventilation cooling towers, and the arrangement shall meet the following requirements.
1 When the number of towers is large, it should be arranged in multiple rows. The ratio of length to width of each row should not be greater than 5.1;
2 The clear distance between the mechanical ventilation cooling towers with ambient air intake shall not be less than 4 times the height of the air inlet of the cooling tower;
3 For the arrangement of more than two rows of tower rows, the clear distance between adjacent tower rows whose major axis is on the same straight line should not be less than 4m;
4 For the arrangement of more than two rows of tower rows, the net distance between the tower rows arranged parallel to each other and whose major axes are not on the same straight line shall not be less than 4 times the height of the air inlet of the tower.
5.3.4 The clear distance between the natural draft cooling tower and the mechanical draft cooling tower shall meet the following requirements.
1 When the water spraying area of the natural ventilation cooling tower is greater than 3000m2, it should not be less than 50m2;
2 When the water spraying area of the natural ventilation cooling tower is less than or equal to 3000m2, it should not be less than 40m2.
6 Circulating cooling water treatment
6.1 General provisions
6.1.1 Circulating cooling water treatment shall include the following.
1 Supplementary water treatment;
2 Scale and corrosion inhibition treatment;
3 microbial control;
4 Side water treatment;
5 sewage treatment.
6.1.2 The design scheme of circulating cooling water treatment shall be determined through technical and economic comparison according to the requirements of heat exchange equipment on the thermal resistance value of dirt and annual corrosion rate, and in combination with the following factors.
1 Water quality control index of circulating cooling water;
2 The quantity and quality of supplementary water;
3 System design and control conditions;
4 Side water treatment method;
5 sewage treatment methods;
6 The impact of treatment agents on the environment.
6.1.3 The design of circulating cooling water treatment shall be based on the average value of supplementary water quality analysis data, and shall be checked with the most unfavorable water quality.
6.1.4 The water quality index of the circulating cooling water of the intercooling open system shall be based on the water quality of the system supplementary water and the structural type, material, operating conditions, thermal resistance of dirt, corrosion rate, and other factors in combination with the formula of water treatment chemicals. It is comprehensively determined and should comply with the relevant provisions of the current national standard "Code for Design of Industrial Circulating Cooling Water Treatment" GB 50050.When the circulating cooling water system uses copper and copper alloy heat exchangers, the NH3-N index in the circulating cooling water system water Should be less than 1mg/L.
6.1.5 The water quality index of the circulating cooling water in the intercooling closed system shall be determined according to the operating characteristics of the system and the requirements of the water-using equipment, and shall comply with the relevant provisions of the current national standard "Code for Design of Industrial Circulating Cooling Water Treatment" GB 50050.
6.1.6 The quality of the circulating cooling water of the direct cooling open system shall be comprehensively determined based on factors such as production process requirements, operating conditions, and supplementary water quality conditions.
6.2 Scale and corrosion inhibition
6.2.1 The scale and corrosion inhibitor formulation for circulating cooling water should be determined by dynamic simulation test and economic comparison.
6.2.2 The thermal resistance value, corrosion rate and adhesion rate of dirt on the water side of the heat transfer surface of circulating cooling water heat exchange equipment shall comply with the relevant provisions of the current national standard "Code for Design of Industrial Circulating Cooling Water Treatment" GB 50050.
6.2.3 The initial dosage of scale and corrosion inhibitors in the circulating cooling water system can be calculated according to the following formula.
6.2.4 When the circulating cooling water system is in normal operation, the dosage of scale and corrosion inhibitors can be calculated according to the following formula.
1 cold open circulating cooling water system can be calculated according to the following formula.
2 cold closed circulation cooling water systems can be calculated according to the following formula.
6.2.5 When the circulating cooling water system uses sulfuric acid to adjust the pH value, the dosage of sulfuric acid should be calculated according to the following formula.
6.3 Microbial control
6.3.1 Microbial control in circulating cooling water should adopt the treatment method of mainly oxidizing biocide and supplemented by non-oxidizing biocide.
6.3.2 The non-oxidizing biocide should have the properties of high efficiency, low toxicity, broad spectrum, wide pH range, little or no interference with the scale and corrosion inhibitors in the system, and easy degradation.
6.3.3 The microbial control indicators of the intercooled open-type circulating cooling water system should meet the following requirements.
1 The total number of heterotrophic bacteria should not be greater than 1×105/mL;
2 The amount of biological slime should not be greater than 3mL/m3.
6.3.4 When the oxidized biocide is continuously added, the capacity of the dosing equipment should meet the requirements of the impact dosage. Dosage can be calculated as follows.
6.3.5 The non-oxidizing biocide should be added irregularly according to the microbiological monitoring data, and the dosage can be calculated according to the following formula.
6.4 Cleaning and precoating
6.4.1 The circulating cooling water system should be cleaned before starting up, and the intercooling open and intercooling closed circulating cooling water systems should be pre-filmed.
6.4.2 System cleaning should be carried out in the order of manual cleaning, water cleaning and chemical cleaning. The system cleaning water before starting up should pass through the bypass pipe of the heat exchange equipment.
6.4.3 The pre-film shall meet the following requirements.
1 The circulating cooling water system after chemical cleaning should be pre-filmed immediately;
2 The formulation and operating conditions of the pre-film agent should be determined by experiments or operating experience under similar conditions according to the material, water quality, temperature and other factors of the heat exchange equipment.
6.4.4 The cleaning water of the circulating cooling water system should be directly returned to the lower sump of the cooling tower through the bypass pipe of the cooling tower upper water, and the pre-coated water should be directly returned to the lower sump of the cooling tower through the upper water bypass pipe of the cooling tower.
6.4.5 When a circulating cooling water system supplies water to two or more production devices that do not start up synchronously, there should be measures for cleaning and pre-filming that do not start up synchronously.
6.5 Sidestream water treatment
6.5.1 When one of the following situations occurs in the design of the circulating cooling water treatment system, side flow water treatment facilities shall be provided.
1 The circulating cooling water is polluted during the circulating cooling process and cannot meet the requirements of the design water quality index;
2 It is necessary to use side flow water treatment to increase the design concentration ratio of circulating cooling water.
6.5.2 The design scheme of side flow water treatment shall be based on the water quality index requirements of the circulating cooling water design, combined with the removed impurities...
Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 50648-2011_English be delivered?Answer: Upon your order, we will start to translate GB 50648-2011_English as soon as possible, and keep you informed of the progress. The lead time is typically 9 ~ 13 working days. The lengthier the document the longer the lead time. Question 2: Can I share the purchased PDF of GB 50648-2011_English with my colleagues?Answer: Yes. The purchased PDF of GB 50648-2011_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to [email protected]. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.
|