ASME PCC-1-2010 pdf download.Guidelines for Pressure Boundary Bolted Flange Joint Assembly.
2 INTRODUCTION A BFJA is a complex mechanical device; therefore, BFJAs that provide leak-free service are the result of many selections/activities having been made/per- formed within a relatively narrow band of acceptable limits. One of the activities essential to leak-free per- formance is the joint assembly process. The guidelines outlined in this document cover the assembly elements essential for a high level of leak-tightness integrity of otherwise properly designed/constructed BFJAs. It is recommended that written procedures, incorporating the features of these guidelines that are deemed suitable to the specific application under consideration, be devel- oped for use by the jointassemblers. Alternative features and methods for specific applications may be used sub- ject to endorsement by the user or his designated agent.
4 CLEANING AND EXAMINATION OF FLANGE AND FASTENER CONTACT SURFACES Before assembly is started, clean and examine flange and fastener contact surfaces as described in this section. With one exception, remove all indications of the pre- vious gasket installation from the gasket contact sur- faces; use approved solvents and/or soft-wire brushes, if required, for cleaning to prevent surface contamina- tion and damage to existing surface finish. Avoid using carbon steel brushes on stainless steel flanges. The exception based on experience is flexible graphite that may remain in the surface finish grooves when either a flexible graphite clad or a spiral-wound gasket with flexible graphite filler is to be used as the replace- ment gasket. (a) Examine the gasket contact surfaces of both mat- ing joint flanges for compliance with recommended sur- face finish (see Appendix C) and for damage to surface finish such as scratches, nicks, gouges, and burrs. Indica- tions running radially across the facing are of particular concern. Refer to Appendix D for guidelines covering recommended limits on gasket contactsurface imperfec- tions and their locations. (1) It is recommended that surface-finish compara- tor gages be available to joint assembly personnel. (2) Report any questionable imperfections for appropriate disposition. If weld repair of imperfections is deemed to be required, see ASME PCC-2, Article 3.5 for repair considerations. Appendix C provides recom- mended final surface finishes.ASME PCC-1 pdf download.