ASME PCC-1 pdf free download

ASME PCC-1-2010 pdf free download.Guidelines for Pressure Boundary Bolted Flange Joint Assembly.
The bolted flange joint assembly (BFJA) guidelines described in this document apply to pressure-boundary flanged joints with ring-type gaskets that are entirely within the circle enclosed by the bolt holes and with no contact outside this circle.’ By selection of those features suitable to the specific service or need, these guidelines may be used to develop effective joint assembly procedures for the broad range of sizes and service conditions normally encountered in industry.
Guidance on trouhleshxting BFJAs not providing leak-tight performance is also provided in this document (Appendix P).
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/performed within a relatively narrow band of acceptable limits. One of the activities essential to leak-free perlormance 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 HFjAs. It is recommended that written procedures, incorporating the features of these guidelines that are deemed suitable to the specific application under corsideration, be developed for use by the joint assemblers. Alternative features and methods for specific applications may be used subject to endorsement by the user or his designated agent.
3 TRAINING, QUALIFICATION, AND CERTIFICATiON OF JOINT ASSEMBLY PERSONNEL
It is recommended that the user or his designated agent provide, or arrange to have provided, as appropriate, essential training and qualification testing of the joint assembly personnel who will be expected to follow procedures developed from this Guideline. Notes regarding qualifying flanged joint assemblers are provided in Appendix A.
See section F-2 of Appendix F for comments on accepting flange joint assembly procedures not currently listed in these guidelines.
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 prerious gasket installation from the gasket contact surfaces; use approved solvents and/or soft-wire brushes, if required, for cleaning to prevent surface contamination 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 replacement gasket.
(a) Examine the gasket contact surfaces of both mating joint flanges for compliance with recommended surface finish (see Appendix C) and for damage to surface finish such as scratches, nicks, gouges, and burrs. Indications running radially across the facing are of particular concern. Refer to Appendix D for guidelines covering recommended limits on gasket contact surface imperfections and their locations.
(1) It is recommended that surface-finish comparator gages be available to joint assembly personnel.
(2) Report any questionable imperfections for appropriate disposition. If weld repair of imperfections is deemed to he required, see ASMF I’CC-2, Article 3.5 for repair considerations. Appendix C provides recommended final surface finishes.
(b) When working with problematic or critical service Isee Note (1) of Table 31 flanges of large diameter with leak histories or suspect fabrication, it is recommended to check gasket contact surfaces of both joint flanges for flatness, both radially and circumferentially. This may be accomplished in many cases using a machinist’s straight edge and feeler gages, hut using a securely mounted run-out gage or field machining equipment capable of providmg accurate total indicator readings may be necessarv when tolerances need to be tight. Appendix D provides flatness tolerance recommendations.
If weld repair is deemed to be required to achieve the required flatness, see ASME PCC-2, Article 3.5 for repair considerations. Appendix C provides recommended final surface finishes.
(c) Examine bolt2 and nut threads and washer faces of nuts for damage such as rust, corrosion, and burrs; replace/correct any damaged components. Likewise bolt/nut combinations for which the nuts will not turn freely by hand past where they will come to rest after tightening should be replaced/corrected; this includes tapped hole threads. (See ASME PCC-2, Article 3.3 that covers repair of damaged tapped hole threads.) If separate washers are scored or cupped from previous use, replace with new through-hardened washers3 (surface-hardened washers are not suitable). The condition of previously-used bolts/nuts has a large influence on the performance of a bolted joint assembly. The following guidelines relating to the reuse of bolts/nuts are offered for consideration.
(1) When using bolts and nuLs of common grade as fasteners, the use of new bolts and nuts up to I’ in. diameter is recommended when bolt load-control methods such as torque or tension are deemed necessary (see Appendix N). For larger bolt diameters, it is recommended that the cost of cleaning, deburring. and reconditioning be compared to the replacement cost and considered in the assessment of critical issues of the assembly. When assessing the cost, consider that working with and reconditioning fasteners in the field may be more expensive than the cost of replacement and that the results of reconditioning can be unpredictable. When coated bolts are used, the remaining corrosion protection and self-lubricating functions are additional considerations with respect to continued use or replacement. See Notes (2) and (3) of Table IMiTable 1. and paras. 7(e) and 7(f).ASME PCC-1 pdf download.