UN 2000-01 Part 1 E (1997-02)

7/24/2019 UN 2000-01 Part 1 E (1997-02)

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KRUPP UHDE STANDARD

Behälter und Apparate; Druckbehälter; Technische Lieferbedingungen Supersedes 93-12

2.1 Permissible stresses.............................................................................................................................................. 12.2 Stress analysis ...................................................................................................................................................... 22.3 Deflection .............................................................................................................................................................. 2

3.1 Drawings and technical documents....................................................................................................................... 23.2 Wall thickness allowances..................................................................................................................................... 23.3 Materials................................................................................................................................................................ 33.4 Construction .......................................................................................................................................................... 3

4.1 General.................................................................................................................................................................. 64.2 Welding ................................................................................................................................................................. 6

4.3 Painting ................................................................................................................................................................. 6

6.1 Radiographic and ultrasonic tests.......................................................................................................................... 76.2 Testing the skirt-to-shell weld ................................................................................................................................ 76.3 Testing the reinforcement rings ............................................................................................................................. 76.4 Hydrostatic test...................................................................................................................................................... 76.5 Inspection.............................................................................................................................................................. 76.6 Inspection documentation...................................................................................................................................... 7

This Krupp Uhde standard applies to pressure vessels and other vessels including accessories of metallicmaterials.This standard specifies the requirements to be taken into consideration for rating at Krupp Uhde's and - if citedin the technical specification - at the manufacturer's. This Krupp Uhde standard does not absolve the userfrom meeting the requirements specified in the statutory regulations, codes and standards.

The scope of supplies covers the complete vessels or equipment according to the relevant specification in-cluding all internals, bolts, gaskets and blind covers as well as the prime coat according to the painting speci-fication.

If the requirements outlined in this Krupp Uhde standard are in contradiction to those outlined in the relevanttechnical specification, the latter shall take precedence.

The permissible tensile stress of the vessel materials is specified in the relevant standard.

The permissible compression stress in the longitudinal direction of the vessel (stress resulting from weight,wind moment, etc.) shall not exceed the lowest value of the following two types of stress:

a) Permissible tensile stress

b) Permissible compression stress derived from the buckling strength calculationaccording to DIN 18800, Part 4, including wind loads as per AD Merkblatt S 3/0, section 4.1.4.6, oraccording to ASME Code, section VIII, division 1, paragraph UG-23 (b) (2).

The permissible stress for anchor bolts is 110 N/mm². During erection or repair work which requires the use of

Date Prepared Date Checked Date Approved

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Page 2 UN 2000-01 Part 1

scaffolding, a stress of 150 N/ mm² is permitted.

The permissible concrete bearing pressure under the base ring is 8.3 N/mm²

In addition to calculating the wall thicknesses, the manufacturer shall make the following stress analyses forthe corroded condition of the vessel:

• Weights: dead weight of the vessel without internals (to be installed later). In the case of heat exchangers,including weight of the tube bundle.Moments: wind moments for vessels including attachments, plus moments from eccentric loads, plus windmoment from the scaffolding.

• Weights: dead weight plus weight of all internals, attachments, insulation and inventories.Moments: wind moments for vessels including all attachments, plus moment from eccentric loads, plusother moments (e.g. nozzle loads). If an earthquake calculation has to be taken into consideration, thewind moment or the earthquake moment - whichever is the higher - shall be applied, unless otherwisespecified in other national regulations.

•

Weights: dead weight plus weight of all internals, attachments, insulation and water inventory.Moments: wind moments for vessels including all attachments plus moments from eccentric loads.

The effect of the forces acting on the nozzles or supports and of the moments acting on the vessel wall shallbe examined on the basis of the BS 5500 or Wichmann, Hopper, Mershon: "Local stresses in spherical andcylindrical shells due to external loadings", published in WRC Bulletin 107.

Supporting brackets shall be designed in such a manner that the max. load (operating weight or weight withwater inventory, wind moment, etc.) can be absorbed by half the number (by at least 2) of supporting brack-ets.

Evidence is required that columns and vertical vessels can be lifted from the horizontal position at one end forerection purposes. Krupp Uhde is requested by the manufacturer to specify the load data.

Adequate wall rigidity of the vessel shall be ensured for transport.

The permissible compression stress according to section 2.1 also applies to the supports (skirts) of verticalvessels and shall also be applied analogously to the hydrostatic test of vessels in their operating position.

Unless otherwise specified, allowance factor FB for platforms, ladders, piping and insulation shall be deter-mined for the wind load according to Krupp Uhde form UF 2000-26.

A rigidity analysis shall be made for the shells of horizontal vessels supported by two saddles. "Stresses inlarge horizontal cylindrical pressure vessels on two saddle supports" by Zick, L.P., published in the WeldingJournal (N.Y.), Res. Suppl., 1971 or BS 5500 App. G., contain generally accepted methods of calculation.

The deflection of columns and vertical vessels caused by wind shall be evidenced by calculation and shall notexceed the value indicated in the technical specification.

Drawings shall be prepared according to Krupp Uhde standard UN V401-01 Part 1. The metric system shallbe used for the dimensions and weights indicated in the drawings. Regarding form and contents, the manu-facturer's drawings shall correspond to the data specified in Krupp Uhde standard UN 2000-10 Part 1.

Wall thickness allowance: This allowance shall take into consideration the minus tolerances permitted ac-cording to manufacturer's and dimensional standards for plates and pipes and the reductions in wall thicknessresulting from the fabrication process (e.g. in the case of cast or deep-drawn components).

Wear allowance (corrosion allowance): This allowance shall be applied to all components coming into contactwith the process fluid. It is specified in the design data sheet.

For multi-chamber vessels, this wear allowance shall be applied to both sides of the partitioning walls.

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UN 2000-01 Part 1 Page 3

Removable internals of non-corrosion-resistant materials shall be provided with the same corrosion allowanceas the vessel, but on one side only. Welded-in internals shall be provided with the corrosion allowance on allsides coming into contact with the process fluid.

Vessels and vessel internals of corrosion-resistant materials require no wear allowance. If erosion or similarphenomena are to be expected, the wear allowance shall be applied.

Cladding and lining of corrosion-resistant materials are considered as wear allowance. This does not apply togalvanized components. Plastic coatings may only be considered as wear allowance if approved by KruppUhde.

Further wall thickness allowances, e.g. allowances for bricklining, external pressure, etc., shall be taken intoconsideration depending on the requirements.

The wall thickness of nozzle pipes shall not fall short of the thickness calculated for the particular operatingconditions and loads plus wear allowance. In addition, the wall thickness shall not fall short of the smaller oneof the two thicknesses listed below:

a) Normal wall thickness of the seamless nozzle pipe plus wear allowance; and the flange neck thickness ofthe standard flange plus wear allowance in the case of manholes and hand holes.

b) Actual wall thickness of the shell or head where the nozzle has been welded.

Material and / or test certificates according to the applicable standard shall be furnished for pressure-bearingcomponents and for parts which are welded to pressure-bearing components.

Shells, heads and reinforcements shall be fabricated from killed cast steels unless unkilled steel has beenexpressly specified.

Components which are subjected to mechanical loads and which are welded in hydrogen service and fabri-cated from Mo or CrMo steels for this reason, shall be fabricated from the same material as the vessel or fromanother steel resistant to hydrogen under pressure. When selecting the materials, API 941 "Steels for Hydro-gen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants"

shall be observed.

For vessels containing caustic soda solution, the application limits regarding carbon steel for operation withcaustic soda solution shall be taken into consideration. Refer to Krupp Uhde standard UN V462-01 Part 1.

The materials shall be selected with a view to proper weldability.

Vessel heads shall preferably be of the flanged dished head type fabricated from one piece. If a theoreticalwall thickness of > 20 mm is required, flanged dished heads or ellipsoidal heads (2:1) or hemispherical headsshall be used.

The cone angle of conical reducing shell sections shall not exceed 60°.

The reinforcements of the openings shall preferably be tubular. This particulary applies to high-strength mate-rials and to theoretically required wall thicknesses of > 20 mm. In the case of dished heads, the edge of thenozzle or reinforcement ring shall be located in the spherical segment of the head.

The distance between the weld of the nozzle or reinforcement ring and a longitudinal or circumferential weld ofthe vessel shall be three times the shell wall thickness, but not less than 50 mm. If this is not possible, thewelds shall be arranged in such a manner that the shell weld is completely interrupted by the nozzle. Thisarrangement may only be used in exceptional cases and requires Krupp Uhde's written approval. In such acase, the area concerned shall be subjected to a surface crack test after the hydrostatic test has been com-pleted.

The reinforcements of steel plate shall be fabricated from the same material as the shell and be provided witha test hole NPT

The nozzle-to-shell weld shall be performed according to Krupp Uhde standard UN V416-01 Part 1. Nozzlessubjected to high loads or to additional loads caused by temperature variations, thermal shocks, changing or

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pulsating stress, shall be attached to the shell by full-penetration welding. The inner edge of the nozzle pipe oropening shall be rounded to a radius of approx. 3 mm. However, in the case of shell wall thicknesses of > 50 mm,the radius shall correspond to the smallest value of the following:

a) ¼ of the shell wall thickness

b) 19 mm

Forged welding neck flanges shall be used for all nozzles of carbon steel. The inside flange bore shall corre-spond to the inside diameter of the nozzle pipe.

The neck thickness of the welding neck flanges shall not be smaller than the required minimum wall thicknessof the nozzle pipe. If this wall thickness is smaller than the neck thickness indicated in the flange standard, astress analysis shall be performed for the flange concerned.

The nozzle lengths shall correspond to the table below:

Table 1.

≥ DN 50

< DN 50

≤ ≤ ≤ ≤

≤ 100 200 250 300

≥ 125 ≤ 250200

≥300 250250 300 350

1) Welding necks shall have the same length as nozzles with flanges.

Nozzles for level gauges and controllers attached to the vessel bottom shall protrude 50 mm into the vessel to

prevent fouling.

Drain nozzles shall not protrude into the vessel.

The nozzle pipes shall have a diameter of at least DN 50; reducing sections of smaller DN shall conform withthe DN of the flanged connection concerned. Deviations require Krupp Uhde's written approval.

The bolt holes of the flanges shall straddle the flange centrelines which shall coincide with or be parallel to thecentrelines of the vessel.

Threades sleeves are not permitted.

Nozzle pipes shall be fabricated from seamless pipes or from pipes longitudinally welded with a welding factor

of 1.0.

For internal atmospheric-pressure tubing, steel plate flanges may be used which, however, shall have thecompanion dimensions of standard flanges.

If the lower manhole of a vessel is located 1200 mm or more above the tangent line or a foot rest, ladderrungs and a holding grip above the manhole shall be provided inside the vessel. Refer to Krupp Uhde stan-dard UN 2000-08 for the design.

Forged welding neck flanges shall be used for all manholes of carbon steel. Block flanges are permitted forhand holes. Other types of flange are only permitted if approved by Krupp Uhde.

The manhole cover shall be provided with a davit. In the case of cold insulation, the cover shall be hinged.Refer to Krupp Uhde standard UN 2000-11 Part 1 or Krupp Uhde standard UN 2000-04.

If membrane or weld-ring gaskets are used, same shall be replaceable without necessitating post-weld heattreatment of the flanges, e.g. by buttering.Unless otherwise indicated in the specification, hexagon bolts may be used for external connections provided

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the pressure is < 40 bar, the temperature is < 300°C and the thread diameter is < 30 mm. In all other cases,stud bolts with two nuts shall be used. Hexagon bolts may be used for internal connections which are notsubjected to pressure.

The tightening torques for pressure-bearing bolted connections shall be specified by the manufacturer.

Two base ring templates shall be fabricated to determine the exact positions of the anchor bolt holes in theskirt of vertical vessels. One template shall be forwarded to the job site as early as possible for the erection ofthe vessel foundation. The second template shall remain in the manufacturer's works. The templates shall befabricated from steel plates of approx. 5 mm thickness and be adequately reinforced for transport.

If the outside diameter is > 2000 mm, the templates shall be split into two segments which shall be joined byfitting bolts.

The top sides of the templates shall be marked with white oil paint and die-stamped letters as follows:

• 0° / 90° / 180° / 270°

• 0° to be supplemented by "north"

• "Krupp Uhde order number"

• "item number"

• "top"

The skirts shall be designed in accordance with Krupp Uhde standard UN 2000-05 Part 4, legs according toPart 5.

Horizontal vessels shall be equipped with saddles. Depending on the max. allowable working temperature, thesupport saddles shall be made of the following materials:

> 120°C steel5 to 120°C steel or concrete with plates of min. 6 mm thickness for corrosion protection

< 5°C steel

For steel saddles of horizontal vessels, refer to Krupp Uhde standard UN 2000-05 Part 1 and Krupp Uhdestandard UN 2000-15.

For field erection of vessels, the erection clips shall be fabricated according to Krupp Uhde standard UN 2000-07Part 1. The erection clips for columns and vertical vessels shall be arranged in such a manner that the vesseltransported in horizontal position can be lifted. If a vessel consists of several sections, the erection clips, clamps,etc. required for each section shall be agreed upon between the erection contractor and Krupp Uhde.

Supports for internals such as supporting grids, vortex breakers, internal manifolds, etc. and all clips welded inplace shall be supplied by the vessel manufacturer. When designing the supporting grid, the pressure drop

shall be taken into consideration as an additional load.

The use of securing devices for the bolts of the internals shall be agreed upon between the manufacturer andKrupp Uhde.

Table 2.

Partitioning plates, downcomerplates, weirs, draw-off pans,clamps, etc.

2 mm

Supports of steel plate, supportinggrids

2 mm

Supports of sectional steel 3 mm3 mm

Bolts M 10 M 10

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Table 3.

≤ 900 40

> 900 ≤ 1700 50

> 1700 ≤ 2600 60

> 2600 ≤ 3600 70

> 3600 ≤ 4700 80

> 4700 90

Lateral downcomer:

2.5 to 3 x support ringwidth

Central downcomer:2.5 x support ring width

6 mm + 2 x corrosionallowance

If the tray manufacturer specifies other dimensions, same shall apply. It must be possible to install and re-move all internals through the manhole. They shall not obstruct the access to the manholes.

Unless otherwise specified, all internals shall be installed prior to delivery.

Internal components such as support rings, braces, webs, supports, etc. shall be attached to the vessel shellor tray by a continuous full-fillet weld, to be welded from both sides. If the component can only be welded on

one side or if the partial pressure of the hydrogen is > 7 bar, full-penetration welding shall be performed. In thecase of vessels with a diameter of > 1000 mm, the welded-in fractionating trays, transverse baffles and parti-tioning plates shall be provided with a folded edge and attached to the vessel by a continuous full-fillet weld.The height of the folded edge shall be four times the plate thickness but at least 50 mm. The edge shall befolded by 75°. The folding angle shall be determined to permit welding of the major portion of the fillet weldsfrom both sides. Internal manifolds shall be provided with flanged connections.

Vertical vessels with insulation shall be provided with clips according to Krupp Uhde standard UN 2000-06Part 1.

The vessels shall be equipped with grounding terminals as per Krupp Uhde standard UN 7061-02 Part 1.

The shell plates shall be dimensioned to permit fabrication of the vessel with a minimum of welds. The minimumdistance between the circumferential welds and the support rings of fractionating trays, etc. shall be 100 mm.Refer to Krupp Uhde standard UN V416-01 Part 1 for the preparation of the welding bevels.

Shell sections shall not be rolled until the actual diameters of the heads have been determined.

When matching shell sections of different wall thicknesses, the vessels equipped with removable internals(e.g. fractionating trays) shall have the same inside diameter. The shell plates of larger thickness shall bechamfered (slope of 1:4) on the outside of the vessel.

Refer to Krupp Uhde standard UN 2000-02 Part 1 for the dimensional tolerances for vessels.

Refer to Krupp Uhde standard UN V416-01 Part 1 and/or UN V416-03 Part 1 for welding including testing,post-weld heat treatment and surface treatment.

Type and scope are outlined in the applicable painting specification.

All vessels shall be provided with a nameplate according to Krupp Uhde standard UN 2000-09 Part 1.

Unless otherwise specified, the nameplate of vertical vessels shall be attached above the lowest manhole andthe nameplate of horizontal vessels at the level of the vessel centerline. Order number, item number andweight shall be indicated in 300 mm block letters with due consideration of the transport position at a con-spicuous place on the vessel with weather-proof white paint.

In the case of vessels of several shell sections including their internals, each section shall be marked individu-

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ally for positioning and assembly purposes.

Also refer to Krupp Uhde standard UN V416-01 Part 1 for procedure and welder’s qualification.

Where random radiographic and / or ultrasonic testing is required, at least one radiograph per weld andwelder, including all junctions, shall be made. Additional verification radiographs can be requested by theKrupp Uhde inspector in justified exceptional cases.

In the case of vertical vessels with a height / diameter ratio of > 18, the preparation of the skirt-to-shell weldshall be witnessed by the Krupp Uhde inspector prior to welding. The root pass and the completed weld shallbe examined for cracks by a magnetic particle test. In the case of austenitic steels, a dye-penetration test shallbe performed.

All reinforcement rings of openings shall be tested for leaks by means of a foaming agent and air at a pres-

sure of approx. 0.5 bar. The test pressure shall start at 0.2 to 0.3 bar. After the test, the test holes of vesselsoperated at a temperature of > 150°C shall be sealed with grease paste or wax. If the operating temperatureis < 150°C, threaded plugs are also permitted.

All vessels shall be subjected to a hydrostatic test. Any other tests, e.g. pressure test with air, are only per-mitted if approved by Krupp Uhde.

The hydrostatic test pressure shall be maintained for a period of 2 hours per 25 mm wall thickness (min. pe-riod 2 hours, max. period 5 hours).

The test pressure shall be determined according to the applicable standard, i.e. for the operating position ofthe vessel measured at the highest point.

Prior to dispatch, the manufacturer shall remove the end caps on nozzles with welding ends and shall re-chamfer the welding ends.

Lined vessels (e.g. rubberlining, brickwork) shall be subjected to a hydrostatic test prior to the application ofthe lining.

In the case of vessels fabricated completely or partly from austenitic steel or equipped with an austenitic lin-ing, the permissible chloride content indicated in Krupp Uhde standard UN V416-04 Part 1 shall be taken intoconsideration for the hydrostatic test.

The test temperature shall be min. 16°C. Higher test temperatures may be required for thick-walled vessels orvessels sensitive to brittle fracture. In the case of test temperatures of < 16°C, the manufacturer shall obtainKrupp Uhde's approval, stating the reasons for the test temperature selected and furnishing proof of thenotched-bar impact strength at the test temperature concerned. The vessel manufacturer is responsible forthe selection of the test temperature.

After completion of all hydrostatic tests, all connections shall be opened, the vessel thoroughly cleaned anddried and all connections shall be re-closed.

All vessels designed and fabricated according to this Krupp Uhde standard are subject to inspection by KruppUhde and / or their client(s) and, if necessary, by the competent inspection authority. The scope of inspectionis specified in the inspection data sheets (IDS) and must be indicated in the manufacturer's fabrication andinspection schedules.

The inspection documentation shall correspond to the applicable standard or technical specification or to thepurchase order.

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The shipping procedures shall correspond to Krupp Uhde’s shipping and packing instructions. It is essentialthat the erection clips be located on the horizontal centerlines.

Krupp Uhde standards:

UN V401-01 Part 1 Technical drawings; Principles of execution; General requirementsUN V416-01 Part 1 Welding; Welded joints for vessels and equipment; RequirementsUN V416-03 Part 1 Vessels and equipment; Surface treatment of austenitic stainless steels after weldingUN V416-04 Part 1 Water quality for pressure tests and flushing of equipment, pipelines and other compo-

nentsUN V462-01 Part 1 Vessels and equipment; Limits for the application of carbon steel in caustic serviceUN 2000-02 Part 1 Vessels and equipment; Dimensional tolerances for steel vesselsUN 2000-04 Vessels and equipment; Hinged manhole coversUN 2000-05 Part 1 Vessels and equipment; Support saddles for horizontal steel vesselsUN 2000-05 Part 4 Vessels and equipment; Supports for vertical steel vessels; SkirtsUN 2000-05 Part 5 Vessels and equipment; Supports for vertical steel vessels; LegsUN 2000-06 Part 1 Vessels and equipment; Insulation clips for vertical steel vesselsUN 2000-07 Part 1 Vessels and equipment; Lifting lugs and lifting trunnions for erection of steel vessels

UN 2000-08 Vessels and equipment; Internals; Vortex breakers, feed deflectors and ladder rungsUN 2000-09 Part 1 Vessels and equipment; Nameplate for vesselsUN 2000-10 Part 1 Vessels and equipment; Title blocks for manufacture’s drawingsUN 2000-11 Part 1 Vessels and equipment; Swivel devices for manhole closuresUN 2000-15 Vessels and equipment; Connection plates for vessels supported by steel structuresUN 7061-02 Part 1 Earthing connections for vessels and equipmentKrupp Uhde forms:UF 2000-26 Vessels and equipment; Determination of allowance factor FB for calculating moments

from wind and other loadsDIN standards:DIN 18800 Part 4 Structural steelwork; Analysis of safety against buckling of shellsOther standards:AD Merkblatt S 3/0 General verification of the stability for pressure vessels; Basic principles

API Publication 941 Steels for Hydrogen Service at Elevated Temperatures and Pressures in PetroleumRefineries and Petrochemical Plants

ASME CodeSection VIII Boiler and Pressure Vessel Code; Rules for Construction of Pressure VesselsBS 5500 Specification for unfired fusion welded pressure vesselsWRC Bulletin 107 Local stresses in spherical and cylindrical shells due to external loadings

Documents

UN 2000-01 Part 1 E (1997-02)