PIPING SYSTEM - ABRASIVE SLURRIES Engineering Standard Specification. 96 B. Riutta

Transcription

1 PIPING SYSTEM - ABRASIVE SLURRIES Engineering Standard Specification Number: Rev. 2 Rubber Lined Steel Pipe and Fittings Mechanically Coupled Plain End Type System Issued Revised Approved Reviewed February, 22, B. Riutta Service This specification covers piping systems for abrasive slurries requiring rubber lined steel pipe and fittings. Pressure Rating deg.f Operating Conditions deg.f Maximum temperature for this lining is 160 deg.f. If oil is present in the slurry, determine the concentration to avoid possible deterioration of rubber lining. Design Fabrication Installation In accordance with American National Standard Code for Pressure Piping, ANSI/ASME B31.3, Chemical Plant and Petroleum Refinery Piping, and Inco Engineering Standard Specification, "Piping - General Requirements". Approvals Slurry systems where the slurry is considered not more hazardous than water are not subject to approval by regulatory agencies provided the pressure is less than 600 PSIG and the temperature does not

2 exceed 150 deg.f. Pipe 2" Through 10" - Schedule 40 carbon steel ASTM A53 Gr. B, E.R.W., plain ends, machined for lapped over rubber lining. 12" Through 16" " thick wall carbon steel ASTM A53 Gr. B, E.R.W., plain ends, machined for lapped over rubber lining. Fittings 2" Through 10" - Schedule 40 carbon steel ASTM A234 WPB, butt weld to ANSI/ASME B16.9, complete with butt welded tangent extensions, plain ends cut square, machined or lapped-over rubber lining. 12" Through 16" " thick wall carbon steel ASTM A234 WPB, butt weld to ANSI/ASME B16.9, complete with butt welded tangent extensions, plain end cut square, machined for lapped over rubber lining. Note: Butt weld elbows - long radius R= 1 1/2 x dia. or 3 x dia. as noted on project drawings. Couplings Mechanical coupling for plain end pipe, bolted cast segments encasing an elastomeric gasket, grade or ductile iron ASTM A536. Hardened electroplated carbon steel jaws. Obtain the approval of the Inco Design Engineer for alternate materials. Coupling Gaskets Synthetic rubber conforming to ASTM D2000 Elastomeric Materials for Automotive Applications. Gaskets to be neoprene. Coupling Bolting Oval track-head bolts and heavy series hex nuts, conforming to ASTM A183, with nuts to ASTM A194 grade 2H.

3 Flanges 2" Through 16" lb. raised face, slip-on, welding neck or lap joint, forged carbon steel ASTM A105, ANSI/ASME B16.5 Bore of welding neck flanges to suit pipe I.D. Flange Bolting Valves Carbon steel bolts to ASTM A307 Gr. B, UNC threads, with heavy series hex nuts to ASTM A563 Gr. A with Class 2A fit on bolts and 2B fit on nuts. Dimensions to ANSI B1.1, B and ANSI/ASME B See project drawings. Pipe Fabrication Dimensions for length of spool are face to face of flange or stub end. Furnish lap joint stub ends complete with lap joint flange on pipe or fitting. Spools and fittings to be fabricated in accordance with Inco Engineering Standard Specification unless otherwise noted. Identify each spool piece by order number and mark number using aluminum paint. Do not weld after preparations for rubber lining are complete or on completion of rubber lining. Pipe Preparation For Rubber Lining Grind smooth, welds that come into contact with rubber lining. Grind welds at flanges to 1/8" min. radius. Grind weld neck flanges to 1/8" min. radius at the inner face edge. Pipe spools to be hydrostatically tested before rubber lining in accordance with ANSI/ASME B Use water as test medium. Pressure test the spools at 225 PSIG for a period of not less than

4 10 minutes but of sufficient duration to examine all joints for leakage. Sandblast or shot blast internal pipe surfaces to a uniform white metal finish to remove all traces of rust, scale or other foreign matter, and free surfaces of laminations, deep seams ridges, pits or other imperfections. Procedure for blast cleaning of steel pipe to comply with Steel Structures Painting Council Bulletin, Surface Preparation Specification No. SSPC-SP-5. When blast cleaning is complete, remove all dust by vacuum or air blast. Coat blasted area with prime coat of bonding adhesive before rusting can take place. Lining Specification Rubber lining to be 40 ± 5 Durometer after vulcanization, soft gum natural rubber at 1/4" minimum thickness. Ensure rubber linings are free of defects, cracks, blisters or bulges and have a smooth surface free of projections. Carry the rubber lining for flanged pipe to outer edges of raised flanges faces such that no gasket is required. Rubber lining at pipe end to be buffed true and square and O.D. at lapped over portion to match pipe O.D. and to have a smooth surface for coupling gasket seating. Rubber lining of elbows and bends 8" and over to be 1/2" thick on the outside radius covering 180 degrees of circumference. Rubber lining to be applied in two 1/4" thick layers. Feather edges of second layer. The tube seam of the first layer to be on the inside radius of the elbow or bend. Rubber lining for valves to be carried to the

5 outer edge of the raised flange face or for flat face flanged valves to the inside of the bolt circle. Full face lining is not required. Lining Procedure Apply remaining coats of adhesive using uniform coats and allowing each coat to dry before applying the next coat. Use adhesive cement of high quality material suitable for maximum adhesion between metal surface and crude rubber compound. Dependent on pipe size, lay several lengths of coarse string full length of surface to be lined. Use no less than 3 lengths of string per length of pipe. Cut sheet of rubber lining and form into a tube with O.D. of tube same as I.D. of pipe. Ensure seam of lining is well knitted and uniformly smooth. Tackify the outside of tube, place tube on liner fabric and draw into place in pipe using caution not to scuff or damage the adhesive cement. Remove the liner and with light air pressure, expand the rubber lining into place inside the pipe. Place pneumatic expander near centre of pipe length and expand rubber liner as expander is inched towards operator. Similarly when first half of lining is expanded into place, repeat for other half of pipe, thus consolidating the lining and removing any entrapped air. Vulcanize rubber lining by steam pressure cure to pipe or fitting. Remove from vulcanizer and spark test whole rubber lining completely. Reline completely any length which displays leaks that cannot be reached for repairs.

6 Make repairs using a chemically cured rubber compatible with lining. Edges of lining at flanges to be chamfered slightly by buffing. Welding Essential variables to be in accordance with Inco Engineering Standard INCO 2" to 6" Root:GTAW Cover:SMAW Procedure No:MS-3 8" to 16" Root:SMAW Cover:SMAW Procedure No:MS-1 Contractors 2" to 6" Root:GTAW Cover:SMAW Essential Var:WP-3 8" to 16" Root:SMAW Cover:SMAW Essential Var:WP-1 Testing Subject the system to the initial service leak test described in ANSI/ASME B using the service fluid as test medium. Test at 100 PSIG unless otherwise specified in project drawings. Increase pressure in steps (increments of 25 PSIG) until the test pressure is reached and hold for no less than 15 minutes but of sufficient duration to examine all joints for leakage. Where no process fluid is available use water as a substitute. Examination Perform nondestructive examination in accordance with ANSI/ASME B Visual examination is required, in accordance with ANSI/ASME B , to the extent necessary to satisfy the examiner that components, materials, and workmanship conform to the requirements of ANSI/ASME B31.3. Acceptance criteria (limitations on imperfection) for welds in accordance with Table A, category D fluid service. Cleaning Following completion of hydrostatic testing, drain the test fluid at a rate of flow sufficient to flush debris or foreign materials from the system.

7 Painting Paint the system only when indicated on drawings. Colour: Light Grey, Federal Standard Colour Pipe Identification Identify the piping system according to the requirements indicated on drawings. In addition to the lettered legend all piping containing combustible liner to have the following words located at 20' - 0" centre to centre maximum. "Caution - Combustible Liner - No Hot Work" END OF STANDARD