Chapter VI Vessel Supports 1
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Vessel Supports Vessel support is to a. Support the weight of the container b. Fix the container position c. Keep the container in operation. Classified by the type of vessels: a. Supports of vertical vessel; b. Supports of horizontal vessel; c. Supports of spherical vessel. 3
Difference between standards of vessel supports ASME BPVC.Ⅷ.1-2015: There are some suggestions at non mandatory appendix G. EN 13445-3(2009) Unfired pressure vessels-part 3: Design : Provide calculation method for supports. JB/T 4712.1~4712.4-2007 Vessel supports-part : Provide detailed selection rules for each kind of support. 4
A. Supports of horizontal vessel saddle support ring support Leg support Lug support B. Supports of vertical vessel Bracket support Skirt support 5
A) Saddle Support 6
A) Saddle Support Rib plate Saddle support is the most widely used horizontal vessel support. Rib plate Bottom plate Saddle support is made of rib plates and bottom plate welded together. From standard JB/T4712.1-2007 Vessel supports-part 1:Saddle support, chose the saddle support according to the nominal diameter and weight of vessel. 7
tangent tangent Saddle bearing angle (θ) Saddle width (b) Saddle bearing angle can be chosen as 120 (,135 ) or 150. The width b is determined by nominal diameter of vessel. Distance from saddle to vessel tangent (A) a. When L/D is relatively large, without stiffness rings, take A 0.25D; b. When L/D is relatively small, /D is relatively large, or with stiffness rings, take A 0.2L. (JB/T4712.1-2007)
Installation of Saddle Support Saddle supports are divided into type A (light) and type B (heavy). Type A and type B are different due to the size or the quantity of ribs plates, bottom plates. Each type of saddle supports can divided into Fixed support (F) and Sliding support (S). 9
B) Ring Support 圈座 Ring Support Situations using ring support: For thin-walled vessels and vacuum vessels; For long vessels with more than two supports. 10
C) Leg support The connection creates a severe local stress and is only suitable for small equipment (DN 1600, L 5m). The detail parameters of supporting legs see standard JB/T 4712.2-2007 Vessel supports-part 2:Leg support. 11
B. Supports of vertical vessels Lug support Bracket support Skirt support 12
A) Lug support Lug support consists of rib plate and stabilizer plate. If with large size or thinwall vessel, base plate is added. It is Simple and lightweight, but with a large local stress. To prevent the loss of alloying elements, eg. stainless steel equipment also need to add a stainless steel plate with carbon steel supports. Widely used in the reactor and vertical heat exchanger and other upright equipment. 13
14 Lug support
Selection method of lug support (1) Estimate the total weight of the equipment, calculate the load Q for each support (calculated on 2 supports); (2) Determine the type of support, select the support according to the standard in accordance with principle that allowable load Q allow is greater than actual load Q. For small equipment, lug support can be put on the pipes or structural steel columns. For Large equipment, supports are often set on the basis of steel beams or concrete. 15
B) Bracket support Made of steel pipe, angle steel and channel steel, or welded by a few pieces of steel plate. Type, Structure, Size and Material see JB/T 4712.4-2007 Vessel supports-part 4:Bracket support. 16
a) It is Simple and lightweight; b) There is a large local stress, and base plate should be set when the shell stiffness is small, or the difference of temperature or material between the shell and the support is large, or the shell need post-weld heat treatment c) base plate and vessel shell should be the same material. 17 Bracket support
The selection of bracket support Bracket support is divided into type A and type B. 4.3.6 δ支座和检查孔 D. Type B Type A 18
Bracket support :type A and type B. shape number nominal diameter(mm) structural properties A 1~6 DN800~3000 Steel plate welding, With base plate B 1~8 DN800~4000 Steel pipe welding, With base plate 19
C) Skirt support a) Tower equipment use skirt support most commonly. b) There is no standard at present for skirt support. c) The dimensions of each part must be determined by calculation or practical experience. 20
21 Skirt support
22 Skirt support
Questions: 1. How many kind of horizontal vessel supports and vertical supports? List them. 2. How many parameters we should consider when determining the position of double saddle horizontal vessel support? 23
Chapter VII Openings and Reinforcement 24
1 Vessel Opening Aim Check the defects, such as crack, corrosion, deformation. Including Manhole, handhole, which position should be easier to observe or clear the inside of the vessel. 25
Stipulate The numbers and the size of the opening should follow the standards or codes. Not Required opening:(satisfies any of the following conditions) Di of cylinder is smaller than 300mm; With detachable head or cover which size is not smaller than the opening s; Without corrosion or week corrosion, do not need check and clean; Vessels with refrigeration function; Heat exchanger; without opening during the design and manufactory process, 100% NDT;Note the calculation thickness; main monitored. 26
2 Reinforcement Reinforcement is necessary due to the openings.? 1 2 3 4 Strength of the wall is decreased due to the opening, discontinuous stress, stress concentration is generated. Stress peak value increases and can be larger than the yield stress. Defects from materials and manufactory process In order to decrease the stress peak value, reinforcement is necessary on the opening area to ensure vessel safety. Due to the effect of stress concentration, the recommend shape for opening is circular. 27
Reinforcement forms ASME UG36-43 Add some metal material around the opening to improve the strength. Reinforcement forms: reinforcement rings, thickness nozzle reinforcement and integral reinforcement reinforcement ring 28
reinforcement ring 29
thickness nozzle integral reinforcement 30
List the reinforcement forms Why we should consider the reinforcement for the vessel? 31