TRCI. Tank Farm- Guidelines for the Chemical Industry. Publisher BCI Basle Chemical Industry

Transcription

1 TRCI Tank Farm- Guidelines for the Chemical Industry Publisher BCI Basle Chemical Industry Edition: 2009 replaces: Edition 2001

2 TRCI Page 2 of 70 Preface to the 2009 The TRCI Guidelines of 2001 had to be reviewed since the VWF (Ordinance for the Protection of Water from Potentially Water-Polluting Liquids) was withdrawn. Instead of the VWF, two enforcement regulations of the KVU (Conference of the Heads of Environmental Protection Offices in Switzerland) are now applicable. The review also updates the entire document and restructures it. The TRCI Guidelines are applicable to storage facilities and plant tank farms in the chemical and pharmaceutical industry. They are applicable to liquid chemicals and can also be used for plant facilities in an analogous manner. They are listed as Engineering Rules by the Swiss Federal Office for the Environment (BAFU). The guidelines are obligatory for the design of storage facilities in the BCI, they serve as a supplement to the provisions and directives of the authorities. A team of experts from CIBA, CLARIANT, HOFFMANN-LA ROCHE, HUNTSMAN and LONZA reviewed the TRCI Guidelines for the BCI. All rights reserved Copyright 2009 by BCI/TRCI The TRCI Guidelines are available in German, French and English via:

3 TRCI CONTENTS Page 3 of 70 CONTENTS CONTENTS General information Introduction Purpose and scope of application Conditions for the operation of tank farms according to TRCI... 6 Page 1.4 Water pollution control areas, ground water pollution control zones and water pollution control measures Classification of liquid chemicals Water pollution control Fire protection Air pollution control Tank farms and transfer sites, definition Tank farms Drum storage Transfer sites Planning and design of tank farms General comments Site selection and assessment of construction site Planned arrangement Tanks in underground concrete spaces Filling points and drum filling points Tank and protective clearance Outdoor storage tanks and drum storage Storage tanks in buildings Outdoor filling points and drum filling points Protective structures, foundations General comments Protective structures Definitions Requirements of protective structures Discharge surfaces Containment trays Containment beds, containment basins Size of protective structures Protective structures of metal Protective structures of mineral-based building materials Linings and coatings Testing of protective structures Foundations... 20

4 TRCI CONTENTS Page 4 of 70 4 Storage tanks and equipment Storage tanks General comments, terms Storage tanks of metal Storage tanks of plastics Heating and cooling systems Inert gas blanketing Tank surface coating Thermal insulation Piping General comments, terms Requirements of piping Design, installation Connection of pipes to tanks and tankers Hoses Gas balance, pressure compensation lines Overspill, overflow equipment Distributing and return lines Testing of piping Pipe insulation Valves and fittings General comments Shutoff valves Vent valves Flame arresters Pumps Instrumentation and control systems General comments, terms Level instruments (level measurement) Overfill protection Leak detection systems Temperature switch / electric circuit breaker Ecology, safety and fire protection Displacement and breathing losses Displacement losses Breathing losses Measures to prevent or reduce emissions Liquid losses Plant safety Ex-zone classification Measures against hazardous effects of electric currents Lightning protection systems Protection against electrostatic charging Safety measures in case of an energy failure General safety measures Fire and explosion protection... 38

5 TRCI CONTENTS Page 5 of General comments Definition, terms Alarms Outdoor fire protection measures Protective measures in buildings Protective measures in electrical rooms Earthquake safety Personal protection Permit and operation Compulsory permit and registration Obligations of the sponsorship or construction management Operating permit Operation and maintenance Operation Maintenance Functional tests Inspection work Qualification of the qualified person Extent of the inspection work Existing facilities and facility parts Decommissioning Annex Minimum dimension of sealed pavings at transfer sites Air pollution control (limit values) Test procedures for facility parts Leakage testing of protective structures Test report Precautions against the hazardous effects of electric current Protection indices (to determine min. fire protection measures) Calculation of the required quantity of cooling water Tank farm design terms Basic documents (laws, regulations, provisions, guidelines) Abbreviations Abbreviations for authorities, regulations, specialist agencies, etc Technical abbreviations Material abbreviation Key words...fehler! Textmarke nicht definiert.

6 TRCI 1 General information Page 6 of 70 1 General information 1.1 Introduction The TRCI are to be applied to the construction and operation of facilities for the storage and transfer operations of liquid chemicals. They take into account the specific requirements of the chemical industry and are mainly based on - the federal law governing environmental protection (Environmental Protection Act [USG]) [3]; - the Swiss Water Protection Act (GSchG) [1] and pertaining regulations; - Ordinance for the protection against accidents (Accident Ordinance, StFV) [7]; - Enforcement regulations and guidelines of the KVU [34 and 35]; - Clean Air Ordinance (LRV) [5]; - SUVA Bulletin 2153, Explosion Protection: Principles, minimum provisions, zones [16]. The TRCI only takes into account regulations, which are valid throughout Switzerland. Depending on the location of the facilities, any special Cantonal or local regulations are also to be taken into account. Any deviation must be agreed during the plan approval procedure. The Engineering Rules are to be adhered to on principle (KVU [34-05]). Chapter 7.10 contains a summary of the basic documents. 1.2 Purpose and scope of application The TRCI are applicable to storage facilities and plant tank farms of the chemical and pharmaceutical industry. They take into account facilities used for storing and transfer of liquid chemicals (tanks and drums with a usable volume above 20l). They only ensure adequate safety when they are applied in their entirety and serve, in particular - the protection of watercourses - fire protection - air pollution control - labour protection (personal protection) The TRCI may also be applied to plant facilities in an analogous manner. The TRCI do not cover the following items - Storage and transfer of liquid fuels (see CARBURA guidelines [8]; - Liquified gases (SUVA [16]) 1.3 Conditions for the operation of tank farms according to TRCI Location: Tank farms are to be installed within an enclosed and supervised area. Tank farms for flammable liquids may only be installed in an area for which a fire brigade trained to deal with chemical hazards is responsible; Operation: The operation of storage facilities must be registered or approved, on principle (see Chap. 6); Safety: Tank farms are to be equipped with safety devices according to Chap. 5; Maintenance and Inspection: Tank farms must be maintained and inspected according to Chap. 6; Register: The operator has to keep a register on storage facilities with potentially waterpolluting liquids.

7 TRCI 1 General information Page 7 of Water pollution control areas, ground water pollution control zones and water pollution control measures Switzerland is divided into water pollution control areas, ground water pollution control zones and ground water pollution control sites with regard to water pollution control measures to be applied (see GSchV Art. 29 and 31 [2]). The principles of handling potentially water-polluting liquids are stated in the Water Protection Act (Art. 22 ff. GSchG [1]) and provisions concerning facilities with potentially water-polluting liquids in particularly endangered water pollution control areas are contained in the GSchV (Art. 32 and 32a as well as Appendix 4, Items 21, 22 and 23). Water pollution control measures outside of ground water pollution control zones and sites (see also KVU [35-1.1]): These include - Prevention of liquid losses; and, depending on the storage facility and the transfer point, - the easy detection of liquid losses or - the easy detection and retention of leaking liquids are demanded. Water pollution control measures in ground water pollution control zones and sites: In relation to the pollution control measures stated above, respective pollution control measures are to be implemented for facilities permitted in ground water pollution control zones and sites which ensure that liquid losses are easily detected and leaking liquids are completely retained. Industrial and commercial operations emanating a danger for ground water are not permitted (see GSchV Art. 29 and 31 [2]). 1.5 Classification of liquid chemicals All liquid chemicals are classified according to the aspects listed below Water pollution control Furthermore, the GSchV differentiates between liquids which can pollute water in small quantities and other potentially water-polluting liquids. Correspondingly, the potentially water-polluting liquids are divided into two classes in relation to their properties according to KVU [35-4]: - Class A: if they can change water adversely in small quantities; - Class B: if they can change water adversely in large quantities. In mixed storage, the measures are in line with liquids of Class A. A list of classified liquids issued by BUWAL (now BAFU) [4] is to be observed. Class 1 of the 1999 list corresponds to Class A today and Class 2 to Class B Fire protection The classification of liquids for fire protection purposes is based on the degree the fire hazard as represented by the flash point (according to VKF [Association of Cantonal Fire Insurance Companies], Fire Protection Guidelines, Flammable Liquids [9]). Flammable liquids are allocated to the following hazard classes according to their fire and explosion properties (EN classification see also allocation table [9]).

8 TRCI 1 General information Page 8 of 70 F1 = Liquids with a flash point below 21 C F2 = Liquids with a flash point of 21 to 55 C F3 = Liquids with a flash point above 55 to 100 C F4 = Liquids with a flash point above 100 C F5 = Liquids, not easily inflammable F6 = Liquids non-flammable Air pollution control The maximum permitted concentrations stated in the Clean Air Ordinance (LRV [5]) must be complied with for tanks venting into the air (Chap. 7.2). Further requirements by Cantonal authorities are to be observed. For information on tank breathing losses, see Chap Tank farms and transfer sites, definition Tank farms Storage facilities with a usable volume above 450 l must be registered or approved (KVU [34-01]). Installation A distinction is made between - Facilities outdoors, Free-standing or Non-free-standing (buried) - Facilities in underground concrete spaces and buildings Free-standing or Non-free-standing (buried) Free-standing refers to storage tanks and pipelines the external walls of which are visible to such an extent that liquid losses can be easily detected from outside; storage tanks are also freestanding if their bottom cannot be seen from the outside but they are permanently monitored by a leak detection system for liquid losses. All other storage tanks and pipelines are considered buried Drum storage Drum storage refers to storing potentially water-polluting liquid chemicals in drums. Drums refers to vessel from 20 l up to a usable volume of 450 l Transfer sites Filling stations and drum filling systems are considered to be transfer sites. - Filling stations: Transfer between transport vessels or between transport vessels and vessels of storage and plant facilities; - Drum filling systems: Transfer from storage or transport vessels to drums.

9 TRCI 2 Planning and design of tank farms Page 9 of 70 2 Planning and design of tank farms 2.1 General comments Site selection and assessment of construction site Important site selection aspects for a new plant or the extension of an existing one: - Local conditions: Ground water pollution control zone including ground water pollution control site, water pollution control area (Chap. 1.4), building zone (according to town planning), transport links (railway, road), availability of firefighting water and containment basin, utility connections (power, nitrogen for blanketing, compressed air for instrumentation and controls, steam for heating purposes, cooling media, etc.), building ground, sewer connection, exhaust air treatment, existing pollution by immission; - Classification of liquid chemicals according to their water-polluting properties and according to their fire hazard ratings (Chap. 1.5); - Liquid chemicals requiring, due to their hazard class, special safety measures; - Obligation to approve, register and control facilities with potentially water-polluting liquids of Class A (KVU [34-01] and [ ]), see also Chap. 6.1: Medium-sized tank farms (with tanks from 2 up to 250m 3 ) in Water Pollution Control Areas A ; Large tank farms (with tanks starting 250m 3 ) in Water Pollution Control Areas A only with exceptional approval and in Area Z only with approval; - Impact of the facility on the neighbourhood: Possible water pollution in the event of an accident, e.g. being in the vicinity of a river, endangering potable water supplies, etc.; Hazard to the neighbourhood through explosion or fire in case of adjoining residential areas, roads with heavy traffic, railway lines, schools, hospitals, due to the immission of aerosols or decomposition products or concurrent evaporation of stored products released in firefighting, etc.; - Impact of the neighbourhood on the facility: Traffic accidents in the immediate vicinity involving reservoirs, neighbouring facility with increased hazard potential, air traffic, earthquake risk, flooding, climatic conditions, e.g. corrosive air from heavy traffic, chlorine or chloride plants (salines), etc. The site selection and decisions on the size of the tanks and the farm as a whole must be made as part of a hazard analysis Planned arrangement When planning a tank farm attention must be paid to: - A clear arrangement of the individual units (rows of tanks, filling/discharging bays, piping networks, pump groups); - Logical division of the complete facility by individual protective structures and fire sections; - Products which could react dangerously with each other or cannot be extinguished with the same fire extinguishing equipment must be stored separately in a suitable manner; - Structural, hazard-oriented separation of tank farms from production facilities, e.g. by safety clearances, fire walls, water curtains, tank zone with non-flammable liquids; - Escape and emergency routes (VKF Guideline 16-03d [9]) - Good accessibility for maintenance, operation and event rectification;

10 TRCI 2 Planning and design of tank farms Page 10 of 70 - The accessibility of tank farms for flammable liquids must be safeguarded for mobile fire extinguishing equipment (vehicles) from at least two sides and every individual tank must be accessible by mobile fire extinguishing equipment from outside of the tank area (Fig. 1+2). Within a group of tanks, the layout of the tanks should be such that "shadow zones" (i.e. zones which the fire extinguishing equipment cannot reach or only with difficulties) do not occur in case of a fire. If this demand cannot be met due to the operational situation, fixed firefighting installations must be provided, firefighting from the top may also be taken into consideration (Fig ); - The distances between tank groups have to be defined according to fire-extinguishing aspects (accessibility, possibility of inserting water walls, etc.). It is advantageous to subdivide bigger tank groups into smaller fire sections (e.g. by fireproof walls or with tanks of non-flammable liquids in between). Fig Tank farm accessible from two sides Fig. 3 Tank farm only Fig. 4 Tanks inside of the tank field (shadow accessible from one side zone) not accessible by mobile fire extinguishing equipment or only with difficulties. Perimeter, drainage In case a storage tank leaks, liquid sprayed beyond the bed (spray parabola) must be collected and handled in a controlled manner. The strip to be drained must have a width of at least 0.5 times the height of the tank above the bed, measured from the tank wall. If tanks are thermally insulated or if they are equipped with protective cladding, this measure is not required.

11 TRCI 2 Planning and design of tank farms Page 11 of 70 For the size of the drained area and retention volume at transfer sites see Chap. 3. The surface of the tank farm perimeter which can be wetted by leaking liquid during operation or in case of accidents is to be of a structure impermeable to liquid, weatherresistant and principally resistant against the goods stored there. These areas are to be drained in a controlled manner. h Tanks in underground concrete spaces General comments 0,5 x h Storage tanks can be erected individually in underground concrete spaces; this arrangement is predominantly employed, if site conditions require the use of space under streets and yards. Structure On principle, the structure is subjected to the same requirements in relation to impermeability as normal protective structures. Selection of tanks For liquids of Hazard Classes F1 and F2 only explosion-resistant or blanketed tanks may be used. Liquids of Hazard Classes F3 and F4 and hardly or non-flammable products can be stored in tanks which are not explosion-resistant. Tanks in underground concrete spaces must be designed without a bottom outlet nozzle. Clearances The clearances between storage tanks and protective structure are to be designed in such a way that visual check of the storage tanks and the protective structures for impermeability is feasible. Where this is not possible, a leakage monitoring system is needed and the storage tanks have to be checked and cleaned inside at appropriate intervals (at least every 10 years) Filling points and drum filling points Construction Filling points are preferably to be constructed as an open or semi-open structure, where necessary with a roof for protection against the elements. Easy detection of liquid losses must be guaranteed. If liquids of Hazard Classes F1 and F2 are filled, non-flammable construction materials are to be used and sufficient separation in terms of fire protection has to be arranged between the filling point, tank farm and the other facilities and buildings. Containment trays, containment beds and containment basins or their coating must be resistant to stored media and leak-proof for at least 6 months, only in exceptional cases for chemicalphysical reasons, the authority issuing the permit may allow a resistance to stored media for the period required to identify the loss, repair the leak and remove the liquid. Ventilation If a closed type of structure is to be used for special reasons, appropriate ventilation and accessibility is to be particularly considered usually requiring induced ventilation. It is to be ensured that ventilation apertures are available also immediately above ground level.

12 TRCI 2 Planning and design of tank farms Page 12 of 70 In semi-open construction, the natural air change is usually sufficient. Appropriate measures must be taken to prevent liquids and escaping vapours from accumulating in rooms at a lower level, or in sewers, pits and the like. See also VKF Guideline 28-03, Chap. 5.5 [9]. 2.2 Tank and protective clearance Tank clearance Minimum tank spacing is defined as the effective clearance between tanks or between a tank and the wall. Anything reducing the effective dimension, e.g. thermal insulation must not reduce the minimum clearance. If a leak occurs in the wall of a tank, the spray parabola must be caught inside or outside of the tank bed (see Chap 2.1.2). Thermal insulation or protective cladding meets this requirement. Protective clearance Protective clearance is measured from the outer edge of the protective structure of the tank farm to the adjoining building under the same ownership or to the building line of the neighbouring lot. The protective clearance can be reduced after consulting the authorities, if suitable measures, such as protective walls, deluge spray systems, or foam, are provided. For tank diameters larger than 10m, it must be verified for each product that the radiant heat on the building line of the neighbouring lot does not exceed 8kW/m 2 in case of a fire. Calculation e.g. according to the Swiss Reinsurance Company [30] Outdoor storage tanks and drum storage Based on the "Fire Protection Guidelines, Flammable Liquids" [9], the following standard values are applicable. Table 2.2.1: Hazard to neighbourhood (degree of hazard) Type of construction (wall facing the neighbouring building) Fire hazard low 1) Use of building Fire hazard normal 2) Fire hazard high 3) Min. EI 60 (nbb) and facing wall without any openings small small small Min. not combustible small medium great Combustible or no wall medium great great Rating examples for type of use according to fire hazard: 1) Manufacturing, processing and storage of non-combustible materials and goods, metal processing 2) Machine manufacturing, offices, apartments 3) Processing and storage of flammable or explosive materials and goods, wood processing

13 TRCI 2 Planning and design of tank farms Page 13 of 70 Table 2.2.2: Outdoor drum storage Hazard to neighbourhood (degree of hazard) Clearance from drum storage to buildings (in m) Hazard Classes F1 and F2 Hazard Classes F3 to F5 Size of store (in m 3 ) Size of store (in m 3 ) up to 5 up to 50 more than 50 up to 5 up to 50 more than 50 small 5* * 8 medium great * No protective clearance if the facing wall corresponds to EI 60 (nbb) and does not have any openings and the accessibility is safeguarded. The protective clearance refers to drum storage if the same drums are stored for a longer period of time. Protective clearance to railway tracks, high-voltage lines and motorways should be the same as for tank farms. Table 2.2.3: Minimum tank and protective clearance Type of vessel Tank size Hazard class Protective clearance Tank clearance A B X 2) Y Explosionresistant tanks or non-explosionresistant, blanketed tanks up to 250m 3 F1 and F2 F3 to F5 NBG low 12m NBG medium 16m NBG high 20m NBG low 6m NBG medium 8m NBG high 10m 20m 10m 0.5 m 1) 0.5 m 1) F 6 l 3) 3) non-explosionresistant tanks up to 500m 3 F1 and F2 NBG low 20m NBG medium 25m 30m NBG high 30m F3 to F5 NBG low 10m NBG medium 12m NBG high 15m 15m F6 3) 3) 0.5 m 1) NBG low 30m F1 and F2 NBG medium 35m 40m NBG high 40m more than F3 to F5 NBG low 15m 500m 3 NBG medium 18m 20m NBG high 20m F6 3) Clearance A and B (VKF), X (KVU), Y (TRbF / CARBURA) see the following figure NBG: Danger to neighbourhood according to Table D = Tank diameter, if there are various diameters the largest one applies. 1) = 0.8m gangway on one side per tank row 2) = The "perimeter, drainage" Chap must be met. 3) = At least the Building Dept. regulations have to be met. 0.5 m 1) 0.3 D min. 1m 0.5 m 1) 0.25 D + 2m min. 3m 0.3 D, min. 1m

14 TRCI 2 Planning and design of tank farms Page 14 of 70 Figure concerning Table A 15.0m X X D Y D X Own lot Neighbouring lot D (Building line) (Building line) Y D Y (Property line) D B Explanation concerning tank and protective clearance (special cases) "Fire Protection Guideline, Flammable Liquids" [9] Railway tracks A protective clearance of 15m to the main tracks is applicable according to the VKF Guideline (28-03) [9]. Further details are also contained in the VKF Guideline. High-voltage lines A protective clearance of 10m is applicable to high-voltage lines [9]. Protective clearances to high-voltage facilities of third parties are to be determined according to the directives of the Swiss Federal High-Voltage Inspectorate Article 16, [23]. If these clearances cannot be complied with, a commission of experts decides on a case-by-case basis on compensatory measures. Roads A protective clearance of 10m is applicable to public roads (up to the roadside) [9]. For motorways, a special Swiss clearance provision in relation to tank farms does not exist. The building lines must always be taken into account. The safety spacing, which is applicable inside the works area, must be complied with as a minimum clearance. Cantonal building authorities are empowered to impose additional clearances from these building lines.

15 TRCI 2 Planning and design of tank farms Page 15 of Storage tanks in buildings Table 2.2.4: Minimum tank and protective clearance for medium-sized, cylindrical tanks Hazard Type of vessel Protective clearance Tank clearance class F1 up to F4 Explosion-resistant tanks or Non-explosionresistant, blanketed tanks No protective clearance Building walls min. EI 90 (nbb) Tank to wall 0.15m Tank to tank 0.25m Service gangway 0.5m F5 and F6 Non-explosionresistant tanks No protective clearance Gangway on one side (escape route) 0.8m Tank to ceiling 0.7m The minimum tank clearances refer to the effective clearance from tank to tank or from tank to wall. 0,7m The clearance between tank (manhole flange) and ceiling must also be ensured. 0,5 m 0,15 m 0,5 m 0,5 m 0,25 m min 0,8 m 0,5 m Anything reducing the effective dimension, e.g. thermal insulation, must not reduce the minimum clearance. 0,25 m 0,5 m 0,5 m 0,5 m

16 TRCI 2 Planning and design of tank farms Page 16 of Outdoor filling points and drum filling points At transfer points for tank wagons, firm installations are to be located outside of the clearance profile for shunting tracks. Table 2.2.5: Minimum protective clearances of filling points Hazard class F1 and F2 F3 and F4 To buildings and facilities outdoors NBG low 6m NBG medium 10m NBG high 15m NBG low 3m NBG medium 5m NBG high 8m To building line on neighbouring lot 20m 12m F5 and F6 Protective clearance according to legal provisions NBG: Danger to neighbourhood according to Table The clearances are determined from the manhole or from the outlet nozzle. For explanations concerning the protective clearance and measures to reduce the clearance as well as special cases see Chap. 2.2 To the pertaining tank farm, a protective clearance is not required. Drum filling points Drum filling points for liquids of Hazard Class F1 to F4 should have, in relation to buildings and facilities, a clearance of at least 3m. For measures to reduce the clearance see Chap. 2.2.

17 TRCI 3 Protective structures, foundations Page 17 of 70 3 Protective structures, foundations 3.1 General comments The structural design, dimensioning and the realisation of tank farms are subject to standards and guidelines. These are, in particular: KVU Guideline [35-1.5] and [35-1.4] SIA 261, SIA 261-1, SIA 262, SIA [25] SN EN [27] The regulations and directives of the Federation, Cantons and SUVA as well as standards based on the same are to be observed. 3.2 Protective structures Definitions Protective structures are constructions which make liquid losses (leakage or overfilling) easily detectable in free-standing facilities or which retain leaking liquid. - Discharge surfaces serve the secure discharge of spray losses or leakages (e.g. suitable roads and yards); - Connecting channels and connecting pipes between discharge surfaces and basins; - Containment trays are waterproof and weather-resistant structures and serve the easy detection of liquid losses; - Containment beds are waterproof structures principally resistant to stored goods and serve the detection as well as retention of leaking liquid. Leaking liquid can also be retained by a separate containment basin; - Containment basins are waterproof structures principally resistant to stored goods and serve the retention of liquids draining from trays and beds. They can also be used to burn off flammable liquids; - Firefighting water containment basins have to be provided for tank farms with flammable liquids. A contingency plan must be available for each case, based on the water quantities of the fire-extinguishing concept Requirements of protective structures The requirements of the KVU Guideline [35-1.4] are to be met. Protective structures must thus be of concrete and placed on a ground which is capable of bearing and frost-resistant. They must resist strains during testing and operation, should not show any permanent deformation and stay waterproof. In particular, the expected chemical strain and earthquakes (see Chap 5.5) are to be taken into consideration. The protective structure is to be dimensioned in such a way that it is resistant to stored media for at least 6 months. In justified cases, the authority issuing the permit may allow a resistance to stored media for the period required to identify the loss, repair the leak and remove the liquid. For protective structures in Ex-zones, measures against static electricity are to be verified. Separate containment basins are recommended for flammable liquids. For checks and maintenance see Chap. 6.4 and 6.5. Repairs must be agreed with qualified persons and sealings should be realised according to the engineering rules.

18 TRCI 3 Protective structures, foundations Page 18 of Discharge surfaces Discharge surfaces shall be waterproof and require a slope to the containment basin Containment trays The containment trays require a slope. Containment trays without a slope require a curb of at least 10cm Containment beds, containment basins Containment beds, containment basins for tank farms The overall area of a tank bed shall not exceed 400m 2 as a rule, otherwise the beds must be subdivided into sections. To limit the water requirement for cooling and foam blanketing in tank farms with flammable liquids, the containment bed is to be divided into sections (e.g. for 2 to 9 tanks) and must have a slope of at least 1.5% so that in case of leaks or overfilling, the liquid cannot spread out under the tank but flows into a suitable containment basin or a separately arranged pump sump (see the following diagrammatic figure). Examples: Containment bed min. 1,5% Pumpensumpf pump sump Containment bed with a separate containment basin min. 1,5% Protective wall Siphon/check valve; may need protection against freezing Separate containment basin quick, safe runoff of larger quantities in case of damage pump sump

19 TRCI 3 Protective structures, foundations Page 19 of 70 In areas where containment volumes are stipulated by law, openings for piping or similar arrangements are not permitted in walls. In exceptional cases, specially appropriate sealing techniques must be used. The dividing walls are lower than the perimeter walls, but, as a rule, are not higher than 0.5m in order to ensure accessibility. Containment basins for liquid losses and drainage for transfer sites If liquid losses have to be retained, the following arrangements may be used as containment basins: - Containment bed in the area of the transfer point; - Lower containment basin of an adjacent tank farm if functioning of the same is not impaired and the transferred goods are not allocated to Hazard Class F1 or F2. At filling points without any roofing, precipitation must be collected and also channelled to the containment basins. The availability of sufficient containment volume is to be checked prior to every transfer. This must correspond to the maximum quantity which may escape up to the rectification of the leak, however, minimum 5m 3 (see also KVU [35-1.1]). For the minimum area of the containment tray for tank wagons and tank lorries see Chap Size of protective structures Protective structures for liquids of Class A must be able to retain at least 100% and liquids of Class B at least 50% of the usable volume of the largest vessel. Possible firefighting water and water from outdoor precipitation are to be calculated in addition. Firefighting water containment basin Containment trays and containment bed, possibly with a separate containment basin, also serve firefighting water containment. The level of the tank bed may only rise to a point where the tanks are not lifted by buoyancy forces, if they are not reliably anchored in this respect. In addition to the containment volume for the tanks, it must be possible to retain at least the firefighting water emerging from the fixed firefighting equipment during 30 minutes as well as an appropriate quantity from the use of mobile equipment (during min.), if separate firefighting containment basins are not available (for details of firefighting water quantities see Chap. 4 and 5). Quantity of precipitation This quantity must correspond to that for a long weekend (3 days at 25 l/m 2 = 75 l/m 2 ). Different climatic conditions may be taken into account depending on the location Protective structures of metal - Protective structures may only be of materials which are sufficiently corrosion-resistant (see Chap ); - The thickness of beds is to be determined by static calculations, if required Protective structures of mineral-based building materials Protective structures of reinforced concrete or prestressed concrete consist of a concrete construction prepared on site and, if required, of a sealing. The concrete structure must be designed in such a way that occurring deformation, particularly creep and shrinking deformation, does not have any adverse influence on the sealing. Building materials: Only high-quality concrete according to EN [27], e.g. NPK C, may be used.

20 TRCI 3 Protective structures, foundations Page 20 of Linings and coatings Linings and coatings are used as sealings and corrosion protection in protective structures: - Coatings based on epoxy resin or bitumen; - Laminates (reaction resins from unsaturated polyester resin, from phenylacrylat resin or from epoxy resin free of solvents are to be used); - Plastic plates; - Joint sealing compounds and joint tapes; - Ceramic linings; - Metallic linings. Sealings of plastic material must have a certificate for water protection capability of an accredited test body (KVU [35-1.6]), must provide the required elasticity and stick to the substrate (base). Foils of plastic material are fixed to the walls (they do not stick to the substrate) Testing of protective structures The manufacturer or the erector must check and document the parts (KVU [35-1.4]). Testing comprises: - Inspection of construction: Workmanship, conformity to drawings; - Quality: Of materials and workmanship (in case of metal beds, in particular the welding seams); - Leakage testing: Water test or another comparable test procedure (see Chap. 7.4 and 7.5). The manufacturer or the erector must issue a test protocol on these tests which records the results. The same must confirm that the part of the facility has been constructed and tested according to the engineering rules and the provisions of the TRCI. The test protocol is to be signed by the manufacturer or the erector and to be delivered to the test report administrator, the owner or the operator of the facility latest upon the acceptance of the facility; the manufacturer or the erector must keep a copy. In case of facilities requiring approval, testing is to be respectively repeated after 10 years (KVU [34-03]). 3.3 Foundations Foundations must be laid in frostproof ground with a good bearing capacity. Dimensioning of the tank supports and the pertaining foundations must be in line with the expected static load as well as with the load-bearing capacity provided for the respective region and the classification of protection requirements in respect of earthquakes (see Chap. 5.5). If the risk exists that a tank might float, the corresponding buoyancy forces must be taken into account when calculating the anchor bolts.

21 TRCI 4 Storage tanks and equipment Page 21 of 70 4 Storage tanks and equipment Manufacturers of facility part must check whether the same correspond to the engineering rules and must document the test results (GSchG, Art. 22 paragraph 4 [1]). See also KVU [35-1.6]. 4.1 Storage tanks General comments, terms This chapter covers medium-sized tanks (usable volumes 2 to 250m 3 ) of metal and plastic material as well as large tanks (usable volume more than 250m 3 ) of metal. Storage tanks of reinforced concrete and prestressed concrete are not covered by the TRCI. Terms - Standard volume: The standard volume is specified according to the R5 series of standard numbers and is smaller or equal to the nominal volume; - Nominal volume: The nominal volume is the maximum quantity of liquid a vessel can hold on basis of the stress calculation and its technical construction; - Usable volume: The usable volume amounts to 95% of the nominal volume for drums, small and middle-sized tanks, 97% of the nominal volume for large tanks; - "Free-standing" storage tanks: see Chap Requirements for storage tanks - Storage tank construction material must be resistant to the stored medium (liquids and vapours), protected against external corrosion and able to withstand the expected thermal and mechanical stress (for metal vessels see EN steel tank horizontal, Annex B [27]). - For leakage monitoring, tanks can also be constructed with a double bottom or a jacket (see Chap ). - For flammable liquids, metallic (incl. coated and lined) storage tanks are to be used. - Dimensioning of tanks and their supports must take the additional forces resulting from an earthquake into consideration (see Chap. 5.5). - Every medium-sized tank or large tank must be equipped with at least one manhole (DN 600). Small tanks must have at least one inspection hole. Classification according to size (usable volume) - Drums 20 l to 450 l - Small tanks above 450 l to 2m 3 - Medium-sized tanks above 2m 3 to 250m 3 - Large tanks above 250m 3 Types of vessels - Drums Cans, barrels, etc. - Small tanks and medium-sized tanks explosion-resistant or non-explosion-resistant prismatic or cylindrical Tanks with a domed or flat bottom; - Large tanks Vertical, cylindrical vessels with flat bottoms are differentiated as follows: a) Vertical tanks where the free space above the stored medium has free access to the atmosphere; b) Vertical tanks with a fixed roof which can support a gauge pressure or partial vacuum in the free space above the stored medium, according to operating conditions;

22 TRCI 4 Storage tanks and equipment Page 22 of 70 c) Vertical tanks with a fixed roof equipped with an internal membrane floating on the stored medium (membrane tanks); d) Vertical tanks whose roof is constructed as a float (floating roof tanks). Other types of vessels not listed above (e.g. spherical tanks) are possible Storage tanks of metal Corrosion When choosing the material and wall thickness, both safety against corrosion (if corrosion is expected, additional costs should be foreseen) and the economic efficiency are to be considered. Explosion-resistant tanks A tank is considered explosion-resistant, if it can withstand an internal explosion and still does not leak. Storage tanks equipped with an inert gas blanketing system are considered to be equivalent to explosion-resistant tanks in relation to their use (hazard class). As a rule, they are used for usable volumes of up to 250m 3 for free-standing storage of highly flammable liquids. - Construction according to BN 76 [36] and Annex, explosion-resistant storage tanks (according to BN 110 [36], flat-bottom tank).the vessel does not leak, even at a maximum explosion pressure of 10bar. A major permanent deformation is acceptable. The tank is operated unpressurised, although a breathing pressure of +200mbar is permissible. Vacuum resistance according to construction drawing; - Construction according to BN 98 [36], explosion-resistant vessels and equipment for flammable liquids and dusts. Designed for a max. explosion pressure or for an explosion pressure reduced by means of relief devices or explosion suppression (see VDI Guideline 2263, [26]). Only small localised permanent deformation may occur. Any desired operating pressure can be taken into account in the calculation; - For horizontal tanks (installation under or above ground) explosion-resistant or non-explosionresistant see EN or -2 [27]; Calculation and testing according to BN: Dimensioning and stress analysis calculation is according to BN 76 and Annex or BN 98. The position, number and nominal width of the required nozzles, manholes and supports are defined in dimensional drawings or sketches (e.g. according to BN 110). The manufacturer must initiate, at one of the listed offices (Switzerland: e.g. SVTI), the preliminary check of the calculation and construction drawing as well as the acceptance after production. Vertical tanks Free-standing vertical cylindrical tanks with a flat bottom resting on a base and a fixed roof (with or without a floating ceiling) or with a floating roof can be used for the storage of all liquids at atmospheric pressure or a slight operating gauge pressure. Calculation and testing: According to SVTI regulations P 5, [24]. Prismatic tanks The vessels must be constructed in such a way that they are resistant to the static head of liquid and to pressures and partial vacuums occurring during operation as well as external stress. If these tanks are tested with a minimum of 0.5bar gauge pressure, they are authorised for the freestanding storage of liquids with flash points of more than 55 C. Calculation and testing: According to SVTI regulations P 2, [24].

23 TRCI 4 Storage tanks and equipment Page 23 of Storage tanks of plastics Generally used up to 100m 3 usable volume for storage of potentially water polluting liquids with a flash point of more than 55 C. Calculation and testing: According to engineering rules, e.g. of the Plastics Association of Switzerland (KVS). In case of a deviation from the technical rules, evidence must be provided that the legal requirements have been fulfilled in another way Heating and cooling systems The following methods are available - Jacket around the tank or pipe wall; - Half coils or heating panels welded to the outer tank walls; - Tubular coils or heating panels inside of the tank; - Tubular coils touching the outer wall of the tank or pipe, possibly embedded in heat transfer cement for improved heat transfer; - Electric heating system by cables or elements; - Closed refrigerant system with circulation pump and cooling machine. - Direct vapour injection into the stored medium; - Re-circulation of the stored medium through a heat exchanger; - Induction-heating systems, which transfer the electrical energy directly into the stored medium, can be considered for heat exchangers and non-flammable liquids; - Tank sprinkling with water. Remarks - The surface temperature of the heating elements or the heating medium temperature to heat flammable liquids must be adhered to according to TR BCI 155, Table [36]; - A heat transfer medium which is non-flammable or flame retardant and frost-resistant and whose boiling point is above the maximum heating temperature is to be preferred in order to avoid system pressure due to vapour tension, e.g. mixtures of water/ethylene glycol; - Any heat transfer medium used must not cause a dangerous reaction when in contact with the stored medium; - Electric heating systems and tracing systems for pipes have the advantage of a uniform heat transfer (W/m 2 ), cost-effective division into individual pipe sections, virtually not heat loss and they represent an economical method of supplying heat energy; - For hazardous zones, heating elements require an Ex test certificate. Cooling procedures Cooling equipment as described above. The refrigerant should be non-flammable or flame retardant, and must not be too viscous at low temperatures, e.g. refrigerating brines Inert gas blanketing In order to avoid the ingress of air into storage tanks, the liquid is blanketed with inert gas (e.g. N 2 ) (see ESCIS Volume 3, [17]). To keep the consumption of the inert gas as low as possible, a large permissible difference between the gas supply pressure and the relief pressure is used. For breathing, automatic pressure relief valves or overflow valves as well as controllers with auxiliary power can be used. They are selected according to tank stability and properties of the stored medium. The set pressure of the control valves must be aligned to the response pressure of the safety valves.

24 TRCI 4 Storage tanks and equipment Page 24 of 70 If a storage tank according to BN 110 is used for non-flammable media or flammable media under inert gas blanketing, the maximum permissible operating gauge pressure amounts to +500mbar, otherwise max. +200mbar. Vacuum protection according to the permissible operating negative pressure of the tank (see details in construction drawings). Example: For a tank according to BN 76 / BN 110: N2-gassing by automatic low pressure reducing valve; e.g. set point 15mbar. N 2 relief by automatic overflow valve; e.g. set point 80mbar (max. permissible 200mbar) Tank surface coating - Function: In addition to its main task of protecting the storage tank against corrosion, the tank coating can also influence warming of the tank and thus breathing losses. The painting system to be used for carbon steel tanks is specified. e.g. by the following guidelines: BN 108 according to System WBZ or SBZ; For insulated tanks, coating with System AB or 2U according to BN 108 is recommended; Non-insulated tanks with primer and topcoat according to BN 108, according to System WBZ or SBZ; Colour of the topcoat as desired; preferred shades Al-silver to white with a total heat reflectance factor W R above 70% (see table below). Special coating materials may also be used as fire protection measures; - Influence of the surface coating on tank warming: According to VDI Guideline 3479, [26] there is a linear relationship between the surface temperature of a hollow body and the total heat reflectance factor. The surface temperature of a body painted in black can be up to 25 C higher in central Europe than that of a similar body painted in white.

25 TRCI 4 Storage tanks and equipment Page 25 of 70 The table below, provides an overview of the total heat reflectance factor W R for the wavelength spectrum of natural sunlight (300 to 4200nm) for various coating colours. Total heat Description of the colour reflectance factor W R in % (rounded off) Black RAL Machine grey RAL Brown RAL Mouse grey RAL Green RAL Blue RAL Silver grey RAL Pebble grey RAL Red RAL Light grey RAL Ivory RAL Aluminium silver RAL Creamy white RAL White RAL Surface coatings: The total heat reflection factors given above as examples were determined for freshly completed coats of paint; they thus correspond to "good paint conditions". For an exact calculation see VDI Guideline 3479, [26] Thermal insulation Thermal insulation (see e.g. BN 56 and BN 58) may be used: - In heated tanks; - For the reduction of temperature fluctuations in the gas space of tanks and thus for the reduction of breathing losses; - As fire protection to prevent the storage medium and the construction from heating up fast instead of tank cooling (see Chap. 5). If thermal insulation has been provided as a fire protection measure, it has to be designed in such a way that dangerous conditions cannot arise at any filling level in the tank for 30 minutes. This requirement is fulfilled, on principle, if BN 111 is used. In this case, the following aspects are to be observed: - Insulating materials must have a Fire Hazard Index of 6 (non-flammable). Mineral fibre sheets bound with wire netting (without any plastic components) and mineral fibre fire protection sheets (coated on one side with aluminium foil) are examples of suitable materials; - The insulating materials must be securely fastened. If, for example, mineral fibre fire protection sheets are used with aluminium as cladding, the fire protection sheets must be secured additionally with a wire mesh; - Tank legs or skirts must also be protected. If it is possible for fire to enter beneath the tank, then this part including the piping and valves and fittings must also be protected; - If other materials are used instead of mineral fibres or foamed glass (e.g. sublimation coatings, sprayed cement, etc.) their suitability must be checked by an authorized institution; - The danger of self-ignition of organic liquids which can soak into the insulation must be assessed in relation to local conditions. Mineral fibres or open-celled material must only be