More about Fabric Expansion Joints (Functioning/Operating Principle) FUNCTION

Transcription

1 More about Fabric Expansion Joints (Functioning/Operating Principle) FUNCTION Non-metallic Expansion Joints are flexible joints designed to provide stress relief in ducting systems by absorbing movement caused by thermal changes. They also act as vibration isolators, shock absorbers and in some instances make up for minor misalignment of adjoining ducting or equipment. They are fabricated from a wide variety of non-metallic materials, including synthetic elastomers, fabrics, insulation materials, PTEF and plastics depending on the designs. a) Reduce vibrations. l b) Dampen sound transmission c) Compensate Lateral, Axial movements d) Low loads e) Large movements f) Reduce fatigue factor g) Reduce Heat loss h) Corrosion, Erosion resistant i) Acoustical Impedance j) Greater shock resistance k) High Temperature resistance OPERATING PRINCIPLE WREN TM designed Fabric Expansion Joints are flexible, reinforced elastomers which are used in ducting systems to meet the following major needs: 1. Protect ducting by absorbing any difference in dimension due to temperature variation or line movement. 2. To protect equipment by reducing equipment vibration. 3. To provide simple connection of misaligned pipes. 4. Elimination of Noise and Vibration. 5. Prevents the propagation of election phenomenon. 6. Movement Accommodation. Expansion and contraction, as well as rapid movements (dynamic stresses) are absorbed by multidirection and often simultaneous deflections: Axial Compression. Axial Elongation. Lateral Deflection. Angular Rotation.

2 DESIGN D.WREN designs Fabric Expansion Joints as per customer s requirements at its computer aided design facility, based on the following data. Selection of Fabric Expansion Joint by the user should be based on the following points. MECHANICAL DATA 1) Application and size 2) Installation space 3) Flowing medium 4) Type of medium 5) Temperature of flowing medium 6) Temperature of Surrounding atmosphere 7) Time duration at maximum temperature 8) Velocity of flowing medium 9) Surge pressure of the system 10) Test pressure of the system 11) Type of pressure i.e. constant/intermittent/shock/pulsating 12) Support details such as fixed & sliding 13) Movement 14) Dimensions 15) Insulation The design is completed by indicating type of: A/FOILS 1) PTFE 2) Lead 3) Aluminum 4) Stainless Steel 5) SS/MS Wire Mesh 6) Fibre glass 7) Others B/COATINGS 1) Neoprene(CR) 2) Hypalon (CSM) 3) EPDM 4) Silicon Rubber 5) Fluorelastomer (FKM, CFM) 6) PTFE (TEFLON)

3 C/FABRICS 1) Canvas/nylon fabric 2) Polyester Fabric 3) Woven glass fabric 4) Texturised glass fabric 5) Ceramic Wool Blanket 6) Glass 7) Glass Wool Blanket 8) Felted insulation blanket 9) Bolsters of different material 10) Other fabric TESTING As Fabric Expansion Joint is assessed on every vital performance criterion: The tests include: 1) Tensile strength 2) Elongation 3) Ageing properties 4) Deflection 5) Heat built up 6) Life Cycle test with load 7) Flexing Test 8) Chemical Test 9) Temperature withstanding Test 10) Pneumatic Leak proof test 11) Stiffness test 12) Vibration test 13) Pinhole test 14) Bonding test 15) Thickness 16) Abrasion

4 PRODUCT APPLICATION ADVANTAGE D.WREN Fabric Expansion Joints are in use in Thermal Power Plants, Atomic Power Plants, Chemical Plants, Paper and pulp Mills, Sewage disposals, Oil Refinery and Pumping Stations a total of more than 100 projects, cumulatively valued at US$ 100 Billion throughout India, Asia & Europe WITHOUT A SINGLE CASE OF FAILURE.

5 ADVANTAGE OF USING D.WREN Largest range of sizes. Extensive research & development capabilities. Assured quality & strict quality control. Technical service & back up. Flexibility to adapt to meet market needs. Specialized testing equipment available for temperature and life cycle test. Traceability of the product from the raw material stage. 30 years of experience in design and manufacture of Expansion joints. Over 5000 fabric expansion joints supplied without a single case of failure. Solution to all Expansion Joints requirements viz. Rubber Expansion Joint, Fabric Joint & Stainless Steel joint available under one roof. Fabrication and assembly are done at our own works under strong technical Back-up Quick delivery.

6 STORAGE INSTRUCTION Expansion Joints are to be stored in a cool, dry airy covered place suitably wrapped Should be stored on Platform / Racks Storage of Fabric Expansion Joints for longer period Air Conditioned Storage is recommended. Should not come in contact with Acid, Alkali, Oil, Grease etc. (Irrespective of services in which to be employed) Should be stored vertically with flanges of the Fabric Expansion Joints in full contact with rack/flooring or parallel to rack floorings when stored in box. The Expansion Joints should not be stored horizontally resting on the integral flange or resting on sidewall or at any angle. To be handled with care while shifting to and from storage and to ensure no external damage occurs. Scores, scratches, indentation are to be strictly avoided specially on faces of the integral flange and the inner outer layer. Steel section and accessories used alongwith the Expansion Joints are to be protected from corrosion effect. Periodical checks and adequate measures if needed should be taken. Steel sections and accessories should be handled properly to avoid any distortion during handling. Expansion Joints in crate packed condition should be unloaded from transport by wire/rope sling carefully and should be stored in clean and dry conditions and must be protected against mechanical damage. Storage must be a covered area at a temperature of 70 Deg. C. to 30 Deg. C. Care should be taken that under no circumstances the insulation layers of joints shoulld be allowed to get wet. Do not unpack the joints until ready for installation. Protective covers should not be removed as long as possible. Transport supports such as Metal/ Wooden props / struts provided between flanges should not be removed until the joints are in position in ductwork.

7 INSTALLATION PROCEDURE Maximum service life depends on careful and correct installation. Transport Expansion Joints to area of installation in packed condition. Flange face of companion flanges in pipeline should be smooth and without any sharp edges. For large size of Expansion Joints installed in horizontal ducts, lifting lugs welded to flanges should be used to hoist joint in position. Joints should only be fitted after all work on the pipeline and flanges has been complete and anchors and supports have been established. This is to avoid any accidental damage due to welding splatter or sharp objects and to ensure that the joints are not overstressed. The bolts on the flanges must be tightened evenly. Uneven tightening may lead to hazardous leakage. Faulty fitting may lead to failure of the expansion joints.

8 PERIODIC MAINTENANCE OF FABRIC EXPANSION JOINTS WREN Fabric Expansion are maintenance free. However, Periodic inspection of the Fabric Expansion Joints prevents the following: Detects leakages between the flange of the Fabric Expansion joints and companion flanges or through the bolts,. Corrective action of tightening the bolts or replacement of flange can avoid a serious problem in future. Detects deterioration of cover rubber which can be avoided by painting with Chloroprene/ Hypalon based paint thus ensuring longer life of the Fabric Expansion Joints. Detects distortion due to fitment or due to excess movements of the pipeline thus avoiding pre-mature failure.

9