Asme viii ucs ppt

SUBSECTION C REQUIREMENTS PERTAINING TO CLASSES OF MATERIALS.

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UCS

PART UCS REQUIREMENTS FOR PRESSURE VESSELS CONSTRUCTED OF CARBON AND LOW ALLOY STEELS.

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UCS-56

UCS-56 REQUIREMENTS FOR POSTWELD HEAT TREATMENT.

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UCS-56

UCS-56 (a) There are 3 situations where PWHT are required; • Thickness controls. (table UCS-56 & Table UCS-56.1) • Process service requirements. (UCS-56(a)) • Welding methods. (UCS-56(a)) Situation.

Requirements;

Thickness controls

Table UCS-56 or Table UCS-56.1.

Service requirement

as set forth in UCS-68.

Welding process; •

Electron beam welding

welding ferritic materials greater than 1/8 in. (3 mm) thick

•

Inertia and continuous drive friction welding

welding P-No. 3, P-No. 4, P-No. 5A, 5B, and 5C, P-No. 10, and P-No. 15E materials of any thickness

•

Electroslag welding

ferritic materials over 1 ½ in. (38 mm) thickness at the joint shall be given a grain refining (austenitizing) heat treatment.

•

Electrogas

ferritic materials with any single pass greater than 1 ½ in.

(38 mm) shall be given a grain refining (austenitizing) heat treatment.

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UCS-56

Temperature

UCS-56(d2)-Heating rates

[400oF/hr]/ thickness.

UCS-56(b) For P-No. 1 materials only, the heating and cooling rate restrictions of (d)(2) and (d)(5) below do not apply when the heat treatment following welding is in the austenitizing range.

800oF Maximum insertion temperature

Time

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UCS-56

UCS-56(d2)-Variation in temperature throughout the portion of the vessel ∆T≤250oF

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UCS-56

UCS-56(f) Weld repairs 1. to P-No. 1 Group Nos. 1, 2, and 3 materials and 2. to P-No. 3 Group Nos. 1, 2, and 3 materials and 3. to the weld metals used to join these materials may be made after the final PWHT but prior to the final hydrostatic test, without additional PWHT, provided that PWHT is not required as a service requirement in accordance with UW-2(a), except for the exemptions in Table UCS-56, or as a service requirement in accordance with UCS-68. The welded repairs shall meet the requirements of (1) through (6) below. These requirements do not apply when the welded repairs are minor restorations of the material surface, such as those required after removal of construction fixtures, and provided that the surface is not exposed to the vessel contents.

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UCS-56

1. The Manufacturer shall give prior notification of the repair to the user or to his designated agent and shall not proceed until acceptance has been obtained. Such repairs shall be recorded on the Data Report.

2. The total repair depth shall not exceed 1 ½ in. (38 mm) for P-No. 1 Group No. 1, 2, and 3 materials and 5⠄8 in. (16 mm) for P-No. 3 Group No. 1, 2, and 3 materials. The total depth of a weld repair shall be taken as the sum of the depths for repairs made from both sides of a weld at a given location.

3. After removal of the defect, the groove shall be examined, using either the magnetic particle or the liquid penetrant examination methods, in accordance with Appendix 6 for MT and Appendix 8 for PT.

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UCS-56

(4) In addition to the requirements of Section IX for qualification of Welding Procedure Specifications for groove welds, the following requirements shall apply: (a)The weld metal shall be deposited by the manual shielded metal arc process using low hydrogen electrodes. The electrodes shall be properly conditioned in accordance with Section II, Part C, SFA-5.5, Appendix A6.11. The maximum bead width shall be four times the electrode core diameter. (b) For P-No. 1 Group Nos. 1, 2, and 3 materials, the repair area shall be preheated and maintained at a minimum temperature of 200째F (95째C) during welding.

Fion Zhang/ Charlie Chong

UCS-56

(c) For P-No. 3 Group Nos. 1, 2, and 3 materials, the repair weld method shall be limited to the half bead weld repair and weld temper bead reinforcement technique. The repair area shall be preheated and maintained at a minimum temperature of 350°F (175°C) during welding. The maximum inter-pass temperature shall be 450°F (230°C). The initial layer of weld metal shall be deposited over the entire area using 1⁄8 in. (3 mm) maximum diameter electrodes. Approximately one-half the thickness of this layer shall be removed by grinding before depositing subsequent layers. The subsequent weld layers shall be deposited using 5⁄32 in. (4 mm) maximum diameter electrodes in such a manner as to assure tempering of the prior weld beads and their heat affected zones. A final temper bead weld shall be applied to a level above the surface being repaired without contacting the base material but close enough to the edge of the underlying weld bead to assure tempering of the base material heat affected zone. After completing all welding, the repair area shall be maintained at a temperature of 400°F ~ 500°F (205°C–260°C) for a minimum period of 4 hr. The final temper bead reinforcement layer shall be removed substantially flush with the surface of the base material.

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UCS-56

(5) After the finished repair weld has reached ambient temperature, it shall be inspected using the same nondestructive examination that was used in (f)(3) above, except that for P-No. 3, Group No. 3 materials, the examination shall be made after the material has been at ambient temperature for a minimum period of 48 hr to determine the presence of possible delayed cracking of the weld. If the examination is by the magnetic particle method, only the alternating current yoke type is acceptable. In addition, welded repairs greater than 3â „8 in. (10 mm) deep in materials and in welds that are required to be radiographed by the rules of this Division, shall be radiographically examined to the requirements of UW-51.

(6) The vessel shall be hydrostatically tested after making the welded repair.

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UCS-56

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UCS-66

Figure 11.2 A specimen PWHT table UCS-56 and UW-40 nominal thickness

API 510 section 8.1.6.4 says that, in principle, repair welding must follow the requirements of ASME VIII (it means UW-40 and UCS-56) but opens the door to two overriding PWHT alternatives set out in API 510 section 8.1.6.4.2. and in aforementioned UCS-56(f) Weld repairs may be made after the final PWHT but prior to the final hydrostatic test, without additional PWHT.

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UCS-56

API510-8.1.6.4.2, Alternative to ASME PWHT Alternative to ASME PWHT P#

1

Preheat

Group 1/2/3 only.

2

3

4

Group 1/2 only. (excl. Mn-Mo steels in G2).

NA

CD

Base Metal

All

Carbon Manganese Steels, 4 Sub Groups Group 1 up to approx 65ksi Group 2 Approx 70ksi Group 3 Approx 80ksi Group 4 -

-

Not Used

ALL

3 Sub Groups:- Typically ½Mo and ½Cr ½Mo Group 1 Group 2 Group 3 -

ALL

2 Sub Groups:- Typically 1¼Cr ½Mo Group 1 Group 2 -

The welding shall be limited to the shielded-metal-arc welding (SMAW), gas-metalarc welding (GMAW), and gas-tungsten arc welding (GTAW) processes.

Note: CD- Controlled depositions.

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UCS-56

NOTES: 1. When it is impractical to post weld heat treat at the temperature specified in this Table, it is permissible to carry out the post weld heat treatment at lower temperatures for longer periods of time in accordance with Table UCS-56.1.

2. Postweld heat treatment is mandatory under the following conditions: a) for welded joints over 1 ½ in. (38 mm) nominal thickness; b) for welded joints over 1 ¼ in. (32 mm) nominal thickness through 1 ½ in. (38 mm) nominal thickness unless preheat is applied at a minimum temperature of 200°F (95°C) during welding; c) for welded joints of all thicknesses if required by UW-2, except postweld heat treatment is not mandatory under the conditions specified below: -------

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UCS-56

Mandatory Fion Zhang/ Charlie Chong

UCS-56

Over 2 in. (51 mm) to 5 in. (127 mm) the PWHT is held for a flat 2 hours for the first 2 inches (51mm) of thickness with an additional 15 minutes per inch over 2 inches. Let’s look at a graphic of this thickness range.

Fion Zhang/ Charlie Chong

UCS-56

UCS-56 REQUIREMENTS FOR POSTWELD HEAT TREATMENT (f) Weld repairs to P-No. 1 Group No. 1, 2, and 3 materials and to P-No. 3 Group Nos. 1, 2, and 3 materials and to the weld metals used to join these materials may be made after the final PWHT but prior to the final hydrostatic test, without additional PWHT, provided that PWHT is not required as a service requirement in accordance with UW-2(a),………

(4) In addition to the requirements of Section IX for qualification of Welding Procedure Specifications for groove welds, the following requirements shall apply: a) The weld metal shall be deposited by the manual shielded metal arc process using low hydrogen electrodes. The electrodes shall be properly conditioned in accordance with Section II, Part C, SFA-5.5, Appendix A6.11. The maximum bead width shall be four times the electrode core diameter. b) For P-No. 1 Group No. 1, 2, and 3 materials, the repair area shall be preheated and maintained at a minimum temperature of 200°F (95°C) during welding. c) For P-No. 3 Group Nos. 1, 2, and 3 materials, the repair weld method shall be limited to the half bead weld repair and weld temper bead reinforcement technique. The repair area shall be preheated and maintained at a minimum temperature of 350°F (175°C) during welding. The maximum interpass temperature shall be 450°F (230°C).

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Preheating Method (Notch Toughness Testing Not Required) & Controlled-deposition Welding Method (Notch Toughness Testing Required) ASME VIII, UCS-56 (4a) The weld metal shall be deposited by the manual shielded metal arc process using low hydrogen electrodes. The electrodes shall be properly conditioned in accordance with Section II, Part C, SFA-5.5, Appendix A6.11.

The maximum bead width shall be four times the electrode core diameter.

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API510 8.1.6.4.2.3, c. The welding shall be limited to the shielded-metal-arc welding (SMAW), gas-metal-arc welding (GMAW), and gas-tungsten arc welding (GTAW) processes.

Preheating Method (Notch Toughness Testing Not Required) ASME VIII, UCS-56 (4b) For PNo. 1 Group No. 1, 2, and 3 materials, the repair area shall be preheated and maintained at a minimum temperature of 200ºF (95ºC) during welding.

ASME VIII, UCS-56(6) The vessel shall be hydrostatically tested after making the welded repair.

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API510, 8.1.6.4.2.2.2 for P-No. 1, Group 1,2, and 3, and to P-No.3, Group 1 and 2 (excluding Mn-Mo steels in Group 2). The preheat method shall be performed as follows: The weld area shall be preheated and maintained at a minimum temperature of 300ºF (150ºC) during welding. The maximum interpass temperature shall not exceed 600ºF (315ºC).

Controlled-deposition Welding Method (Notch Toughness Testing Required) ASME VIII, UCS-56 (4b) For P-No. 3 Group No. 1, 2, and 3 materials, the repair weld method shall be limited to the half bead weld repair and weld temper bead reinforcement technique.

The repair area shall be preheated and maintained at a minimum temperature of 350ºF (175ºC) during welding. The maximum interpass temperature shall be 450ºF (230ºC)…..After completing all welding, the repair area shall be maintained at a temperature of 400ºF–500ºF (205ºC–260ºC) for a minimum period of 4 hr.

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API510, 8.1.6.4.2.3 (d) For P-No. 1, P-No. 3, and PNo. 4 steels. A weld procedure specification shall be developed and qualified for each application. The welding procedure shall define the preheat temperature and interpass temperature and include the post heating temperature requirement in f(8). The qualification thickness for the test plates and repair grooves shall be in accordance with Table 8-1. (f7) The welding technique shall be a controlleddeposition, temper-bead or half-bead technique. The specific technique shall be used in the procedure qualification test.

UCS-66 MATERIALS.

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UCS-66

The main material property that API 510 / ASME VIII is concerned with is that of resistance to brittle fracture. The fundamental issue is therefore whether a material is suitable for the minimum design metal temperature (MDMTdesign) for which a vessel is designed. This topic is covered by clause UCS-66 of ASME VIII.

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UCS-66

Steps: 1. UG-20 for exemption on impact testing.

2. UCS-66.

• Identified material Group A,B,C,D. • Figure UCS-66 to determine the allowable MDMT. • Figure UCS-66.1 to determine the reduction in MDMT based on coincident ratio.

3. UCS-68(c) to determine on further reduction in MDMT.

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UCS-66

Figure UCS 66.1 Coincident Ratio The Coincident Ratio is based on a vessel’s extra thickness due to its design calculations which were based on its Maximum Temperature.

Meaning that; As metal’s temperature increases its strength decreases, hotter means weaker, therefore the allowable stress is decreased during calculations resulting in vessel that requires thicker walls when hot than when it is operating at its coldest temperature, the MDMT. This ratio takes credit for the extra wall thickness that is present, but not needed to resist pressure at the MDMT. The following graphic will help. Usually when there is a drop in temperature there is also a drop in the pressure. The two operating conditions are calculated and the Ratio is determined. This Ratio is given on the exam and you need only use the table to apply this rule.

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UCS-66

How to use FIG. UCS-66 & FIG. UCS-66.1 to determine impact test value (MDMT allowable)

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UCS-66

Steps: 1. Determine material group.

2. Determine MDMT allowable on the graph.

3. If Design MDMT higher than MDMT allowable, no test requires.

4. If MDMT allowable is higher than design MDMT goto FIG. UCS66.1 Fion Zhang/ Charlie Chong

UCS-66

Steps: 5. If the coincident ratio is 0.70 reduction of 30oF from the MDMT allowable. The revised MDMT’ allowable = 59oF. 6. If the revised MDMT’ allowable is higher than the design MDMT, check on item 7.

7. If material is P1, UCS-68(c) If postweld heat treating is performed when it is not otherwise a requirement of this Division, a reduction of 30oF. The resulting MDMT allowable may be colder than 55oF.

Fion Zhang/ Charlie Chong

UCS-66

Once the MDMT allowable had been ascertained, further reductions are possible by within -55ยบF capping with exception; 1. Low coincident stress ratio 2. postweld heat treating is performed when it is not otherwise a requirement of this Division on P1 materials.

-

o 55 F

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UCS-66

UCS-66 (b2) For minimum design metal temperatures colder than 55ºF (-48ºC), impact testing is required for all materials, except as allowed in (b)(3) below and in UCS-68(c).

UCS-66 (b3) When the minimum design metal temperature is colder than -55ºF (-48ºC) and no colder than -155ºF (-105ºC), and the coincident ratio defined in Fig. UCS-66.1 is less than or equal to 0.35, impact testing is not required.

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UCS-66

UCS-66 (b2) For minimum design metal temperatures colder than 55ºF (-48ºC), impact testing is required for all materials, except as allowed in (b)(3) below and in UCS-68(c).

UCS-68(c) If postweld heat treating is performed when it is not otherwise a requirement of this Division, a 30ºF (17ºC) reduction in impact testing exemption temperature may be given to the minimum permissible temperature from Fig. UCS-66 for P-No. 1 materials. The resulting exemption temperature may be colder than -55ºF (-48ºC).

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UCS-66

UCS-68 DESIGNS.

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UCS-68

UCS-68(c) If postweld heat treating is performed when it is not otherwise a requirement of this Division, a 30째F (17째C) reduction in impact testing exemption temperature may be given to the minimum permissible temperature from Fig. UCS-66 for P-No. 1 materials. The resulting exemption temperature may be colder than -55째F (-48째C).

-

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o 55 F

UCS-68

Material Group Applicable Materials Curve A

Curve B

Curve C

Curve D

Bolting and Nuts

•

All carbon and low alloy steel plates, structural shapes, and bars not listed in Curves B, C, and D.

•

SA-216 Gr. WCB and WCC, SA-217 Gr. WC6, if normalized and tempered or water-quenched and tempered.

•

SA-216 Gr. WCA if normalized and tempered or water-quenched and tempered

•

SA-216 Gr. WCB and WCC for maximum thickness of 2 in., if produced to fine grain practice and water-quenched and tempered

•

SA-217 Gr. WC9 if normalized and tempered

•

SA-285 Gr. A and B

•

SA-414 Gr. A

•

SA-515 Gr. 60

•

SA-516 Gr. 65 and 70 if not normalized

•

SA-612 if not normalized

•

SA-662 Gr. B if not normalized

•

Except for cast steels, all materials of Curve A if produced to fine grain practice and normalized which are not included in Curves C and D

•

All pipe, fittings, forgings, and tubing which are not included in Curves C and D

•

Parts permitted under Para. UG-11 shall be included in Curve B even when fabricated from plate that otherwise would be assigned to a different curve

•

SA-182 Gr. 21 and 22 if normalized and tempered

•

SA-302 Gr. C and D

•

SA-336 Gr. F21 and F22 if normalized and tempered

•

SA-387 Gr. 21 and 22 if normalized and tempered

•

SA-516 Gr. 55 and 60 if not normalized

•

SA-533 Gr. B and C

•

SA-662 Gr. A

•

All material of Curve B if produced to fine grain practice and normalized which are not included in Curve D

•

SA-203

•

SA-508 Cl. 1

•

SA-516 if normalized

•

SA-524 Cl. 1 and 2

•

SA-537 Cl. 1, 2, and 3

•

SA-612 if normalized

•

SA-662 if normalized

•

SA-738 Gr. A

See Figure UCS-66 of Division 1for impact test exemption temperatures for specified material specifications.

Material Groups for Impact Test Exemptions Table 3.1

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