[7T04-CS-00-PC-011] Procedure for Alloy Steel Piping_Rev

8/9/2019 [7T04-CS-00-PC-011] Procedure for Alloy Steel Piping_Rev

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CONSTRUCTION PROCEDURE

FOR

ALLOY STEEL PIPING

Doc No : 7T04-CS-00-PC-011

Rev. : 13

Page : 1 of 9

Date : 17. OCT. , 2013


FOR

ALLOY STEEL PIPING

PROJECT NO. : 7T04

PROJECT NAME : ERC Refinery Project

COMPANY : Egyptian Refining Company (TAKRIR) S.A.E.

SITE : Mostorod, Egypt

13 17.OCT, 2013 Revised as Noted S.S.Kim B.G.Min S.M.Hong K.H.Min

12 15.MAY, 2013 Revised as Noted S.S.Kim B.G.Min S.M.Hong K.H.Min

11 09.APR, 2013 Revised as Noted S.S.Kim B.G.Min S.M.Hong K.H.Min

10 10.APR, 2009 Revised as Noted S.S.Kim B.G.Min H.J.Lee S.S.Ahn

0 25.FEB, 2009 For Approval S.S.Kim B.G.Min H.J.Lee S.S.Ahn

REV. DATE DESCRIPTION PREPD CHKD CHKD APPR

(P/M)

REVD DATE

CONTRACTOR COMPANY

SEOUL, KOREA


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TABLE OF CONTENTS

1 SCOPE -------------------------------------------------------------------------------- 3

2 MATERIALS ------------------------------------------------------------------------ 4

3 GENERAL --------------------------------------------------------------------------- 4

4 FABRICATION --------------------------------------------------------------------- 4

5 WELDING --------------------------------------------------------------------------- 5

6 PREHEATING ---------------------------------------------------------------------- 7

7 POSTWELD HEAT TREATMENT --------------------------------------------- 8

8 INSPECTION ----------------------------------------------------------------------- 9

9 PRESSURE LEAK TESTING ---------------------------------------------------- 9


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1

SCOPE

1.1This Procedure covers the minimum requirements for fabrication, inspection and testing of piping made

from C-1/2Mo, chromium-molybdenum alloy steels, 12Cr stainless and austenite stainless steels of the 18-8

type for the ERC Project job site construction, Mostorod, Egypt.

1.2The SUBCONTRACTOR shall comply with all the specification and procedure requirements unless a

change or deviation is approved by CONTRACTORs and COMPANYs representative in writing.

1.3DEFINITION

- COMPANY ; ERC( Egyptian Refining CO.,) and PMC (Project Management Consultancy; Worley

Parsons)

- CONTRACTOR ; GS E & C ( GS Engineering & Construction CO.,)

- SUBCONTRACTOR ; The Party(s) which carry(s) out all or part of Design, Procurement, Installation,

and Testing of the piping system as specified by CONTRACTOR.

1.4RELATED CODES AND SPECIFICATION AND PROCEDURE

The following code and specification are applicable.

ASME B31.3 : Process Piping

ANSI/ASME B 1.20.1 : Pipe Threads, General Purpose

ASME/ANSI B 16.5 : Pipe Flanges and Flanged Fittings

ASME Boiler and Pressure Vessel Code, Section V

7T04-MP-00-TS-004 : Piping Material Specification and classes

7T04-MP-00-TS-012 : Piping Support

7T04-MP-00-TS-013 : Fabrication and Installation Detail Drawings for STD Piping

Support

7T04-CS-00-TS-001 : Painting

7T04-CS-00-TS-003 : Pipe Welding and Welding Inspection

7T04-CS-00-TS-016 : Field Pressure Testing of Piping

7T04-CS-00-PC-009 : Piping Construction Works

7T04-CS -00-PC-013 : Piping Pre-Fabrication

7T04-CS -00-PC-016 : Socket and Seal Welding of Small Piping Component

7T04-QA -00-PC-007 : Field Inspection and Test plan


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7T04-QA-00-PC-004 : PMI Procedure

2 MATERIALS

2.1All materials shall be as shown on the drawings and specifications. No material substitution shall be made

without written approval by CONTRACTORs and COMPANYs representative.

2.2When materials are supplied by the SUBCONTRACTOR, prior to commencement of fabrication, material

test report, chemical analyses results and material certificates shall be submitted for approval.

2.3Welding electrodes, filler wire and consumable inserts shall be in accordance with Specification 7T04-CS-

00-TS-003. Use of non-conforming electrodes must be authorized by CONTRACTOR.

3 GENERAL

3.1Alloy piping shall be fabricated, inspected and tested in accordance with ANSI B31.3 Code for Process

Piping, unless otherwise specified in this Procedure.

3.2The reference of Procedure Carbon Steel Piping,(7T04-CS-00-PC-008), Piping Construction Works,(7T04-

CS-00-PC-009) and Specification for Field Pressure Test of Piping,(7T04-CS-00-TS-016), also apply to the

alloy materials covered by this specification, except as otherwise specified herein.

3.3Stainless steel Pre-Fabrication including material handing and storing shall be well separated for other steel

pre-fabrication works. Tool and equipment to be used shall be suitable for stainless steel and shall not be

used on any other materials.

4 FABRICATION

4.1Edge Preparation

4.1.1 Edge preparation for welding shall be by machine cutting wherever practicable. If flame cutting is

employed, alloy steels shall be preheated at 149-315 . After cutting, the heat-affected zone shall be

ground or machined off for a distance not less than 3mm.

Flame cutting for stainless steel is not allowed.

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4.1.2

End preparation of groove for butt welding shall be as shown in Figure 4.1.2

Figure 4.1.2 Groove Design Tolerances for Use without Consumable Inserts

4.2Bending

Neither hot nor cold bending shall be performed on alloy steel or stainless steel piping without special

written approval by CONTRACTOR and COMPANY. Normally, approved manufactured fittings shall be

employed in conformance with the piping specifications.

5 WELDING

5.1

Qualification of Welders

5.1.1 All welders shall be qualified in accordance with Specification 7T04-CS-00-TS-003.


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5.1.2 When a welder is to be qualified to weld austenitic stainless steels, carbon steel pipe may be used for

the test, but welding must be done with the same electrodes, filler wire and inserts required for the

pipe fabrication.

5.2 Welding Process & Electrodes

5.2.1 Welding Process and electrodes shall be in accordance with Specification 7T04-CS-00-TS-003.

5.2.2 Where is no specified for filler wire, it is acceptable use wires or welding rods of the same nominal

composition as the base material.

5.2.3 In welding alloy materials with low-hydrogen electrodes, it is essential that electrodes be stored in hot

boxes and be kept dry at all times. When working on field welds, portable hot boxes shall be used at

each welding location. Only a few electrodes at a time shall be taken from the hot box for welding.

5.2.4

Extreme care shall be taken not to mix up different alloy electrodes. Each portable hot box shallcontain only one type of electrode. Before any alloy electrodes are used approval from

CONTRACTORs Inspector shall be obtained.

5.2.5 When alloy electrodes are placed in the large stationery hot box, each type of electrode shall be in its

original container or in a separate metal box or compartment with the electrode identification clearly

marked on it.

5.3 Welding Technique

5.3.1 When pipe is in the horizontally-fixed position, welding shall be uphill. In GTAW of the first pass, the

head of the torch shall be positioned perpendicular to the joint, and the arc shall not exceed 3.2mm.

5.3.2 To start the root pass, the electrode shall be held stationary until a white globule appears on the

surface of the pool. After this occurs, the torch shall be moved at such a speed as to maintain the white

bubble at the arc point, generally 50-75mm per min.

5.3.3

If the arc is broken while making the root pass, welding shall be started about 2.5mm in back of where

the weld was terminated to fuse the crater, which normally contains defects.


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5.3.4

When completing the root run the white bubble shall be maintained until there is an overlap of about

6mm from the start of the weld. The bubble must then the welded out of the pool by moving the torch

towards the side of the prepared joint to the outside wall of the pipe where the arc is broken.

5.3.5 The argon flow rate for the welding torch shall be sufficient to prevent oxidation and porosity. Good

protection shall be provided against wind to assure that there is no loss of the shielding gas during

welding.

5.4

Argon Back Purge

5.4.1 An argon back purge shall be used during GTAW. The pipe shall be scaled for the purge with heavy

cardboard dams unless otherwise specified. Generally a flow rate of about 4 to 6 liters per minute is

required. The required amount depends upon the sealing condition. Inadequate purging will result in

oxidation and a rough appearance of the weld internally, which are not acceptable.

5.4.2 When GTAW is used for field welds, where it is not practical to purge the entire line, a small opening

shall be made in the fusible insert at the top of the weld to permit argon purge gas to enter the pipe.The dams shall be positioned prior to fitting up the pipe, and they shall be located about 150mm from

the weld to prevent burning, melting, or other damage to dams from the heat of welding. Whenever

preheating is used, this distance should be increased to keep the metal temperature at the dam no

higher than 150 .

6 PREHEATING

6.1Unless otherwise specified, molybdenum or chromium-molybdenum steels and 12Cr stainless steels shall be

preheated at 200-315 for all welding, includi ng tacking and repair welding. Preheating shall be performed

by torch heating with propane burners is acceptable provided that the temperature is maintained properly.

Any preheating shall be applied as all round as possible, avoid hot spot. The preheat temperature shall be

kept the same as preheating temperature during welding. Thus, when torch heating is used, there must be

available for each weld either two burners with their own gas supply or one burner connected to a manifold-

gas-supply system.

6.2The preheat temperature shall be checked with temperature indicating crayons, such as Tempilsticks. The

welder or welder's helper shall have the crayons with him at all times during welding, and he shall check the

temperature frequently to ensure that the preheat temperature requirements are met. In addition, the

SUBCONTRACTOR shall assign one person the sole responsibility of ensuring that preheat requirements


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are met at all times. It is essential that preheating be carried out faithfully to avoid cracking and other

problems which could result in failure.

7 POSTWELD HEAT TREATMENT

7.1The post-weld heat treatment shall be in accordance with Specification 7T04-CS-00-TS-003.

7.2

Alloy Steels and Ferritic Stainless Steels

7.2.1 Molybdenum or chromium-molybdenum steels and 12Cr stainless steels shall be heat treated after

welding, as indicated in ANSI B31.3. Heating and cooling rates shall be 167 maximum per hour

from, or to 316 .

7.2.2 Heat treating shall be done with electric resistance or induction coils. The complete heat-treating cycle

shall be indicated on a chart from a multipoint recorder. For temperature measurements, at least two

thermo-couples shall be attached to each weld 180 degrees apart using an Inconel-type electrode, suchas Incoweld A, or Inconel filler wire with GTAW.

7.2.3 Preferably, the welded joint shall be heat treated immediately after welding without allowing the

metal to cool below the minimum preheat temperature.

7.2.4 After welding 5Cr-1/2Mo Steel or higher ferritic alloy steels, the weld shall be allowed to cool to the

200-315 preheat temperature range before final postweld heat treatment is applied.

7.2.5 When the intermediate treatment is used, temperature indicating crayons shall be used to ensure that

heating is within the specified range.

7.2.6 Prior to hydrostatic testing, the full postweld heat treatment shall be performed with exception of

hydro test vents and drains shall be postweld heat treatment after hydro test.13

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Rev. : 13

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Date : 17. OCT. , 2013

8

INSPECTION

8.1All Non-Destructive Examination shall be in accordance with Specification 7T04-CS-00-TS-003 and

Reference Procedure 7T04-CS-00-PC-009.

8.2NDE

8.2.1 Welds shall be radiographed shall be as specified for specification 7T04-CS-00-TS-003 Table 1 extent

of NDE of pipe work welds.

8.2.2 Normally radiographic examination of alloy steels shall be performed after the completion of weldto

permit repairs to be made prior to the final heat treatment. All repaired areas shall also be

radiographed.

8.3Hardness Testing

The hardness of all alloy steels shall be checked by CONTRACTOR for conformance with ANSI B31.3.The maximum Brinell Hardness of the weld or heat-affected zone shall be 225 for C-1/2Mo and 1-1/4Cr -

1/2Mo steel and 241 for higher alloy steels.

8.4PMI (Positive Material Identified)

8.4.1 PMI shall be performed in accordance with PMI Procedure (7T04-QA-00-PC-004).

8.4.2 PMI is intended to avoid the risk of receiving incorrect materials and missing material in fabrication

shop or construction site and ensure the correct materials used in the proper places.

9 PRESURE LEAK TESTING

9.1Prior to initial operation, all installed piping system shall be pressure leak tested in accordance with

Specification 7T04-CS-00-TS-016.

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