ASME PCC-1–2010 pdf download

ASME PCC-1–2010 pdf download.Guidelines for Pressure Boundary Bolted Flange Joint Assembly.
7 LUBRICATION OF “WORKING” SURFACES 5 Lubrication reduces the coefficient of friction and results in less required torque to achieve a given tension, improves the consistency of achieved load from bolt to bolt within the joint, and aids in the subsequent disas- sembly of the fasteners. The reference torque values for new, coated bolts/ nuts shown in Table 1M/Table 1 do not consider lubrica- tion other than that provided by the bolt/nut coating [see Note (2) of Table 1M/Table 1]. When reusing coated bolts or if lubricant is applied to new or reused coated bolts,the NutFactorwill change andtherefore thetorque values should be adjusted accordingly (refer to Appendix K). Do not apply either approved lubricant or unapproved compounds to the gasket or gasket-contact surfaces; protect against inadvertent application to these surfaces. (a) Ensure that the lubricant is chemically compatible with the bolt/nut/washer materials and the process fluid. Particular care should be taken to avoid lubricant chemistry thatcould contribute to stress corrosion crack- ing, galvanic corrosion, oxygen auto-ignition, etc. (b) Ensure that the lubricant has proven to be suitable for the expected range of service temperature(s) and antiseize requirements. (c) Before lubricant is applied to the bolt and nut threads, nuts must run freely by hand past where they will come to rest after tightening. If nuts will not turn freely by hand, check for cause and make necessary corrections/replacements.
(e) For new coated bolts and nuts (see Notes to Table 1M/Table 1), free running nut checks as described in (c) are required; however, lubricant application as described in (d) should be limited to the second and subsequent tightening operations since the coating pro- vides sufficient lubrication for the first tightening. (1) The reference torque values for new, coated bolts/nuts shown in Table 1M/Table 1 do not consider lubrication other than that provided by the bolt/nut coating[see Note (2) ofTable 1M/Table 1]. Whenreusing coated bolts or if lubricant is applied to new or reused coated bolts, the Nut Factor will change and therefore the torque values should be adjusted accordingly (refer to Appendix K). (f) While it is recognized that the inherent lubricity of new coated bolts results in less torque being required during the first tightening operation to achieve a given level of tension in the bolt (see Table 1M/Table 1), the major long-term value of coated bolts is to protect against corrosion of the exposed threads and to mini- mize break-out and nut-removal torque, thereby pro- moting ease of joint disassembly [see section 15, and Note (3) of Table 1M/Table 1]. (g) Do not apply either approved lubricant or unap- proved compounds to the gasket or gasket-contact sur- faces; protect against inadvertent application to these surfaces. 8 INSTALLATION OF BOLTS Install bolts and nuts so they are hand-tight with the marked ends of the bolts and nuts located on the same side of the joint and facing outward to facilitate inspec- tion; thensnug up to 15 N·m (10 ft-lb) to 30 N·m (20 ft-lb), but not to exceed 20% of the Target Torque (see section 12). If nuts do not hand tighten, check for cause and make necessary corrections. 8.1 Bolt/Nut Specifications Verify compliance with bolt and nut specifications [materials, diameter, length of bolts, thread pitch, and nut thickness equal to the nominal bolt diameter (heavy hex series nuts)].
10 TIGHTENING OF BOLTS Using the selected tightening method/load-control technique (see para. 10.1), tighten the joint using either the torque increment rounds shown in Table 2 and either the companion Table 4 or Table 4.1 cross-pattern tight- ening sequences when using a single tool as described in section 11, or one of the alternative tightening/ numbering systems shown in Alternatives #1, #2, and #3 of Appendix F. Alternatives #4 and #5 illustrate alternative group numbering systems and tightening sequences when simultaneously using multiple tools. NOTE: When hydraulic bolt tensioners are employed, use the procedure recommended by personnel who are experienced and qualified in controlled bolting services. Guidelines on use of con- tractors specializing in bolting services are provided in Appendix G. It is recognized by Appendix S of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 that the initial tightening of the bolts in a joint comprising flanges designed in accordance with Appendix 2 of that Code is a prestressing operation and that the level of required Target Bolt Prestress can vary considerably above the code tabulated design-stress value.