ASME PCC-2S pdf free download

ASME PCC-2S-2015 pdf free download.Supplement to ASME PCC-2-2015 Repair of Pressure Equipment and Piping.
3.3 Examples of Damage
Figure 2 shows examples of damage that can occur in Cr—Mo pressure vessels with or without stainless steel cladding or weld overlay The examples are typical of high-temperature, high-pressure (HTHP) pressure vessels in refining service.
3.4 Development of Weld Repair Procedures
(a) The selection of weld repair method should be based on the reliability of the repaired area considering the future operation period, as shown in Fig. 3.
(b) Sleeve repair and partial patch repair methods (see Table 5) are normally applied temporarily and are not recommended for periods beyond the next upcoming shutdown or outage without appropriate nondestructive examination (NDE) and applicable fitness-for- service assessment.
3.5 RepaIr Welding Methods Applicable to Cr—Mo Vessels
Some applicable repair welding approaches and alternatives to postweld heat treatment (PWHT) and the ASME PCC-2 Articles in which they are described are listed in Table 5, along with some additional limitations and considerations.
3.6 Welding and Preheat
When the actual aged condition of the component to be repaired cannot be sufficiently evaluated for development of a repair welding procedure, a bead-on plate test should be used to verify the repair welding procedure.
NOTE: A bcadn phite test u a type of self-restraint weld test used to evaluate the cracking seii ilivity of the base matenals and arc welding consumables. Refer to Kayano et at. and Yarnamoto d at (see section 7, References).
4 FABRICATION
4.1 Weld Repair Procedures
(a) Weld repair procedures may be developed as indicated in Table 6.
(b) The welding procedure specification (WPS) shall be qualified in accordance with ASME IWVC Section IX, as applicable, and/or the requirements imposed by the applicable code of construction.
4.2 Preparation for Welding
(a) For shielded metal arc welding (SMAW), drying of electrodes shall be carried out to minimize the potential for hydrogen cracking.
(b) Welding bevel surfaces shall be clean, dry, and free of oil, paint, or other contaminants.
4.3 Welding Conditions
(a) To prevent hardening of welds, weld beads less than 50 mm (2 in.) in length should be avoided.
(1’) Special precaution shall be taken to guard against brittle fracture due to local thermal temperature gradients.
(c) For one-side repair welding of piping, back shielding should be considered for 2’/4Cr—lMo and higher alloy steels.
(d) The temper bead welding method may be considered after evaluation in some cases for low alloy welds when I’WHT will not be carried out. See para. 4.7.
4.4 Preheatlng and Post-HeatIng
(a) To prevent hardening of welds and cold cracking, preheating, post-heating, and dehydrogenat ion heat treatment (1)111”) shall be mandatory unless paras. 4.5 through 4.7 stipulate otherwise.
(b) Typical preheating and welding interpass temperatures are indicated in Table 7.
4.5 De-Embrittlement Heat Treatment
When the materials are severely cmhrittled. a deembrittlement heat treatment operation may be used to recover toughness of material, as shown in Table 8.
4.6 Dehydrogenation Heat Treatment
The preheat temperature should be maintained until PWI-IT or DHT is performed. When the materials are required to cool to ambient temperature after repair welding, dehydrogenation heating shall be carried out at a minimum of 300°C (570°F) for a minimum of 1 h, or for a duration to be agreed upon between the purchaser and fabricator, to prevent cold cracking.
4.7 Postweld Heat Treatment
(a) PWHT should be performed when required per applicable construction codes or standards.
(b) Temper bead and other welding methods as detailed in ASME PCC-2, Article 2.9 may be applicable to some low-chrome steels when corresponding WPSs or procedure qualification records are developed specifically for the welding repair considering welding position and welding circumstances.
(c) Temper bead methods are usually not appropriate for 2’/4Cr—lMo and higher-chrome materials used for hydrogen service because of the high weld-metal and heat-affected zone (H AZ) hardnesses generated by the welding process.
(d) In case of local PW1IT, the PWIIT procedure developed shall include the arrangement of thermocouples and insulation to minimiie the thermal stresses generated during the I’WI-IT operation. AWS Dl0.10 and WRC Bulletin 452 provide guidelines for developing a PW1-IT plan with specific band widths (soak band, heated band, and gradient control band) to ensure that thermal gradients are not harmful.ASME PCC-2S pdf download.