power plant Miscellaneous

 

power plant
Miscellaneous

    Steel Structure, Platforms & Stairs

 General

        Steel structure and platforms shall be provided to facilitate easy access to all valves, equipment, instruments, etc. for operation and maintenance.

 All main valves, meters, instruments, etc. 

 must be accessible from at least one side within man-height level.

        The structure, platforms support, and walkways shall be fabricated in general compliance with 12-SAMSS-007.

 A rigid, self-supporting structure, fabricated from appropriate structural steel material shall be furnished. Welded construction shall be employed throughout.

 

       The structure, platform grating, etc. shall be hot-dipped galvanized.

Minimum platform/walkway width shall be 1000 mm (3'-4").

 The platform shall be accessed via stairs unless otherwise approved.

Pad eye type lifting plates shall be provided for lifting the skid.

  The lifting plates shall be designed and located to enable lifting with equal weight distribution.

The skid structure, including in-place pipe and equipment, supports, shall be designed, fabricated, assembled 

    Skid structure shall be designed of structural dead loads, water-filled pipe and equipment loads and a 130 kph wind velocity.

         All structural steel shapes, bars, and plates shall conform to ASTM-A36, API 5L, Grade B or ASTM A53, Grade B or ASTM A106, Grade B, unless specified otherwise.

Skid structure shall be fabricated and assembled within AISC tolerances.

 All connections shall be welded in accordance with AWS D1.1 and welds shall develop the full strength of the member.

The structure, platforms etc

1st       12-SMSS-007

2nd      20-SMSS-001

3rd       Occupational Safety and Health Act (OSHA)

4th       American Welding Society (AWS)

5th       American Institute of Steel Construction (AISC)

6th       American Society for Testing Material (ASTM)

7th       ASTM A-36 Standard Specification for Structural Steel

8th       ASTM A-488 Qualification of Procedures and Personnel for the welding of steel castings.

         Welding

          General

         All welding works shall be carried out in accordance with the latest edition of API standard 1104, ASMI Section-IX

The Contractor shall be responsible for the quality of welding carried out by his organization and shall conduct the tests of the welding procedure to determine its suitability of ensuing welds which shall meet the requirement of the latest Saudi Aramco standards.

        The Contractor shall also conduct the qualification tests of their welders and welding operators to ensure that they are competent and qualified enough to achieve the required quality.

         The Contractor shall maintain a record of the results obtained in welding procedure and welder operator performance qualifications.

The welders identification number or symbol shall be stamped near each executed welding.

ii.          Welding Procedure Specifications (WPS)

1)           The Contractor shall qualify the welding procedure specification by the welding of the specimens/test coupons according to the latest relevant.

2)         The Contractor shall list the parameters applicable to welding that is performed in the construction of weldments built in accordance with the ASME Section IX 

3)         The Contractor shall prepare “Weld Tables” in accordance with SAES-W-012, indicating line designations, materials, thickness and welding process, etc.

4)         The welding shall not commence until the WPS

5)         All joints shall be prepared according to the relevant standards.

6)         Surfaces to be welded, shall be free from oil, grease, foreign matter, corrosion products, and humidity and shall be free from protective coatings as well.

7)         Tack welds used to secure alignment shall be removed completely.

 If tack welds are to be incorporated into the final weld, their stopping and starting ends shall be properly prepared by grinding, so that they may be satisfactorily incorporated into the final weld, provided the tacks are not cracked and are made with the same material and procedure as the main weld. Cracked tacks shall be removed completely.

iii.         Procedure Qualifications Record

The Contractor shall prepare and submit PQR for each welding process on Saudi Aramco format as per SAES-W-012 to record all the data, variables, results, etc. of weld test coupons.

iv.         Non-Destructive Testing (NDT

1)         The extent of weld inspection, the final weld quality, and the method of examination shall be carried out as per the latest related Saudi Aramco standards.

2)         The Contractor shall maintain adequately indexed records of all the welding, weld inspection, and repairs, which shall be available for the company representative.

c]         Flanges, Gaskets, Bolts & Nuts

i.          Flanges

1)         The flanges, gaskets, bolts, and nuts shall conform

2)         The flanges to be used shall be forged carbon steel, weld neck, raised face type, with a class matching the pressure rating of the relevant piping. Another type of flanges can be used subject to Owner/Engineer’s specific approval based on acceptable technical justification by the Contractor.

ii)         Gaskets 

1)         The gasket to be used shall conform standards including those mentioned above under Item (a), ASME B31.3, and ASME B16.20.

2)         The gaskets shall be compatible with the flange facing, the strength of the flange, and bolting.

3)         The gaskets to be used shall be spiral wound type 316 stainless steel winding, flexible graphite filled, with carbon steel guide ring as per ASME B16.20 for raised face flanges.

            Another type of gaskets can be used upon specific approval by Owner/Engineer based on acceptable technical justification by the Contractor.

iii)         Bolting 

1)         Bolting for flanged joints shall conform to all the relevant Saudi Aramco standards, ASME B16.5, and ASME B16.47.

2)         The material shall be ASME A193 grade B7 stud bolts with ASTM A194 grade 2H nuts, unless otherwise approved by Owner/Engineer on acceptable technical justification by the Contractor.

3)         Washers shall be provided in accordance  having material compatible with bolting and the flange.

4)         Special washers and kits shall be used where necessary, such as insulating flanges, in conformance

5)         The bolt tightening shall be in conformance with the sequence and torque specified in SAES-L-050.

d]         Traps

i.          Automatic traps will be provided to automatically drain out the liquid from the gas lines and equipment,

ii.          The traps material shall be suitable to handle liquid hydrocarbons and water.

iii.         The traps shall be provided with isolating valves and a bypass valve to facilitate maintenance and manual drainage.

iv.         The outlet of the traps shall be led to the slop tank.

e]         Sampling System

i.          Gas samples are required to be taken to determine the gas composition, relative density, and BTU content. Samples shall be collected at least once a week using automatic gas samplers.

ii.          Sample collection control systems shall be time-based in sampling rate. The sample rates of volumes shall be unaffected by variances in pipeline or sample cylinder pressures or temperatures.

iii.         ANSI 316 stainless steel sampler probes 1/8 inch or 1/4 inch diameter tubing and of the single tube or dual pitot tube configuration shall be used. For pipes up to 12-inch size, the probe trips shall be located near the center of the pipe and for pipe larger than to 12 inches in size, the probe tip shall be at least 1/6th of the pipe's internal diameter.

iv.         Constant pressure sample cylinders shall be used.

f]          Burn Pit/Flare System and Ignitors

i.          Burn pit(s)/flare systems of adequate size shall be provided, standards, for disposal of vented gas and hydrocarbon waste through burning.

ii.          A suitably designed ignitor shall be provided to ignite the pilot gas, which in turn ignites the vented gas and waste.

iii.         The system shall comprise all the necessary equipment, instruments required for the smooth, reliable, and safe operation of the system.

iv.         The location of the burn pit/flare system shall be at a safe distance from the main equipment to preclude any fire hazard.

v.         The Contractor shall propose a flare in place of the burn pit, as an option, for burning of gases for Aramco approval.

g]         Nitrogen Purging System

i.          Purging of lines for maintenance and other activities shall be carried out by the use of Nitrogen gas.

ii.          Contractor shall supply a complete Nitrogen gas system comprising of Nitrogen tank/cylinders, pressure gauges, pressure regulators, storing facilities with proper sheds and appropriate connections dedicated to respective equipment and interconnection piping.

iii.         Nitrogen purge connections shall be provided at suitable locations with the approval of the Owner/Engineer.

h]         Utility System

i.          Potable water and other utilities, as necessary, for the facilities at RPP-10 end shall be extended from RPP-10 installation of the system(s) and it shall be carried out in compliance

ii.          A hose reel station with a rubber hose of at At least 40m in length with quick coupling shall be provided.

iii.         At shall be made to hook up the tanker trucks for the supply of potable water as required.

i]          Data Sheets

Reference is made to the forms of Bidder’s Data Sheets of these Specifications. The blank forms

 contained therein shall be completely filled in and submitted together with the Bid.