Inspection Test Plan (ITP) adalah document quality yang harus disiapkan oleh fabricator sebelum proses fabarikasi, construksi, dijalankan.

Berikut ini adalah step step bagaimana membuat dan menyiapkan sebuah ITP dalam pekerjaan consturction fabrication :

Step 1
Read the contract documents (including the technical specifications) and prepare a list of any discrepancies, ambiguities, missing information and standards of materials and/or workmanship that it is considered are inappropriate.

Step 2
Contact the customer and resolve the issues listed as a result of Step 1.

Step 3
Examine the scope of work and divide it into separate areas requiring an Inspection and Test Plan (where not already prescribed in the contract documents). As a general guide it is normally most convenient to document a separate Inspection and Test Plan for each trade or work area/section.

Step 4
Note the Hold and Witness Points required by the customer (including as listed in the contract documents).

Step 5
Review the contract documents again and note the requirements that have the most impact on the quality of the finished work. For each ask the question “What will be the consequences if it is not made sure this is right?” Be certain to include any references to tests, submitting information to the customer, obtaining approvals and Hold and Witness Points.

Step 6
Determine from Step 5 which items or aspects of each inspection will need to be recorded on checklists and prepare these.

Step 7
Discuss the checklists with those directly involved with the work and obtain their input. This input should particularly be directed at identifying those issues that have caused problems (and involved extra costs) in the past, and therefore warrant checking at the earliest opportunity to avoid unnecessary and costly rectification.

Step 8
Prepare each Inspection and Test Plan to reflect the requirements of the contract documents. Reference the ITP in the Quality Management Plan and cross-reference to the other related ITPs.

Step 9
Issue each Inspection and Test Plan and/or associated certification to the customer for consideration within a reasonable period prior to commencing the work described in the Plan and adjust them to suit any comment received (or act as otherwise required in the contract documents).

Step 10
Decide how best to divide the whole of the work into work areas for control purposes and indicate these locations either on a schedule (with reference to grids and levels) or by marking up drawings.

Step 11
Prepare and issue checklists for each work area and identify them according to location.

Step 12
Train those directly involved with each of the ITP in their use. Formalise a procedure for the notification of Witness and Hold Points to the appropriate person(s).

Step 13
Carry out inspections and tests in accordance with the Inspection and Test Plans, provide notices to the customer and/or regulatory authorities for Hold or Witness Points, as designated or applicable, and record the results on checklists.

An Inspection and Test Plan identifies the items of materials and work to be inspected or tested, by whom and at what stage or frequency, as well as Hold and Witness Points, references to relevant standards, acceptance criteria and the records to be maintained. Inspection and Test Plans, when properly implemented, help ensure that, and verify whether, work has been undertaken to the required standard and requirements, and that records are kept.

Dari pengalaman dilapangan banyak para inspector atau contractor dilapangan kurang sreg dengan downhill progression karena anggapan penetrasi yang kurang.

Anggapan tersebut memang beralasan, namun harus dipahami juga dari design calculation tidak semua member fillet weld vertical menghendaki deep penentration, sehinnga pada kondisi tertentu downhill progression bisa membantu produktifitas tanpa mengurangi requirement yang diperlukan.

Article di bawah ini bisa memberikan sedikit gambaran tentang technik downhill progression.

We use either downhill or uphill welding in the vertical position. Downhill welding is carried out with a downward progression, conversely, uphill moves in an upward progression. Downhill welding is often used for fillet welding of steel sheets due to the following advantages over uphill welding.

(1) Faster welding speed

(2) Easier to obtain small-leg fillet weld

(3) Shallower penetration

(4) Lower heat input due to faster welding speed

(5) Less welding distortion

However, downhill welding can inhibit penetration and generate slag inclusions unless a welder can control the arc to track correctly on the welding line at fast speeds (e.g. 60 cm/min or higher with a 1.2-mmφwire). The following measures can prevent defects in vertical fillet downhill welding.

(1) Use the straight run technique without weaving.

(2) Control the welding torch so that the work angle is 45 degrees and the drag angle, 5-15 degrees as

shown below.

Another difficulty with downhill welding is that it tends to cause a concave bead having an insufficient throat (concavity) in vertical fillet welding. To overcome this problem, two-layer welding is recommended as shown in the following figure. Even in the second layer, again, use the straight run technique without weaving.

With respect to welding wires suitable for downhill welding, the following choices are recommended in conjunction with suitable droplet transfer mode and application.

(1) Solid wires for welding sheet metals by using a short-circuiting arc at the low current range (e.g. 50- 160A for 1.2mmφ wire), such as MG-51T (ER70S-6)

(2) Flux-cored wires for welding sheet metals by using a short-circuiting arc at the low current range (e.g. 50- 180A for 1.2mmφ wire), such as MX-100T (E71T-1, E71T-1M)

(3) Flux-cored wires for welding thin plates by using a globular arc at the middle to high current range (e.g.200-300A for 1.2mmφ wire), such as DWA-50 (E71T-1M), DW-100 (E71T-1), DW-110 (E71T-1),and MX-Z210 (E70T-1)

Before employing downhill welding, weldpenetration, joint alignment tolerance and the welder’s skill should thoroughly be examined to ensure that the weld satisfies the requirements. For your information, AWS D1.1 (Structural Welding Code － Steel), for example, specifies that a change from uphill to downhill or vice versa is the essential variable requiring requalification of the welding procedure specification.

Source : Cobelco News

Sering kita melihat valve yang terpasang di system perpipaan namun kita banyak yang masih bingung perbedaan penggunaan dari berbagai type valve ini.

Dibawah ini disajikan tanya jawab tentang valve. Semoga bermanfaat dan bertambah ilmunya.

1. What are the steps in selection of valve?

Ans : What to handle, liquid, gas or powder, fluid nature, function, construction material, disc type, stem type, how to operate, bonnet type, body ends, delivery time, cost, warranty.

2. What are functions of valves?

Ans : Isolation, regulation, non-return and special purposes.

3. What are isolating valves?

Ans : Gate, ball, plug, piston, diaphragm, butterfly, pinch.

4. What are regulation valves?

Ans : Globe, needle, butterfly, diaphragm, piston, pinch.

5. What are non-return valves?

Ans : check valve,

6. What are special valves?

Ans : multi-port, flush bottom, float, foot, pressure relief, breather.

7. What materials are used for construction of valves?

Ans : Cast iron, bronze, gun metal, carbon steel, stainless steel, alloy carbon steel, polypropylene and other plastics, special alloys.

8. What is trim?

Ans : Trim is composed of stem, seat surfaces, back seat bushing and other small internal parts that normally contact the surface fluid.

9. Which standard specifies trim numbers for valve ?

Ans : API 600.

10. What are wetted parts of valve?

Ans : All parts that come in contact with surface fluid are called wetted parts.

11. What is wire drawing?

Ans : This term is used to indicate the premature erosion of the valve seat caused by excessive velocity between seat and seat disc, when valve is not closed tightly.

12. What is straight through valve?

Ans : Valve in which the closing operation of valve is achieved by 90degrees turn of the closing element.

13. What pressure tests are carried out on valves?

Ans : Shell-hydrostatic, seat-hydrostatic, seat-pneumatic

14. What are available valve operators?

Ans : Handlever, handwheel, chain operator, gear operator, powered operator likes electric motor, solenoid, pneumatic and hydraulic operators, Quick acting operators for non-rotary valves (handle lift).

15. What are two types of ball valve?

Ans : Full port design and regular port design, according to type of seat, soft seat and metal seat.

16. What are ball valve body types?

Ans : Single piece, double piece, three piece, the short pattern, long pattern, sandwitch and flush bottom design.

17. Why ball valves are normally flanged?

Ans : Because of soft seat PTFE which can damage during welding.

18. What are butterfly valve types?

Ans : Double flange type, wafer lug type and wafer type.

19. What are types of check valve?

Ans : Lift check valves and swing check valves.

20. What are non-slam check valves?

Ans : Swing check valve, conventional check valve, wafer check valve, tilting disc check valve, piston check valve, stop check valve, ball check valve.

21. Where stop check valve is used ?

Ans : In stem generation by multiple boilers, where a valve is inserted between each boiler and the main steam header. It can be optionally closed automatically or normally.

22. Where diaphragm valves are used ?

Ans : Used for low pressure corrosive services as shut off valves.

23. What is Barstock Valve?

Ans: Any valve having a body machined from solid metal (barstock). Usually needle or globe type.

24. What is BIBB Valve?

Ans: A small valve with turned down end, like a faucet.

25. What is Bleed Valve?

Ans: Small valve provided for drawing off liquid.

PURGING DALAM WELDING STAINLESS STEEL

 

 

 

 

 

 

 

 

 

 Biasanya kalau kita melakukan pengelasan stainless steel , titanium atau material tahan korosi lainnya selalu melakukan purging atau infuse istilah lapangannya… Apa sih yang diinfus…? ( kayak orang sekarat aja …)

Sebenanrya tujuan utama dari purging adalah mempertahankan sifat ketahanan korosi material selama pengaruh panas welding tetap prima dan tokcer .

Sebagaimana kita ketahui pada waktu welding terjadi pemanasan yang dapat merubah sifat dari material. Pengelasan SS terjadi peristiwa oxidasi apabila lingkungan disekitarnya mengandung oksigen ( H2O jadi H2 dan O2 ). Nah peristiwa inilah yang harus dihindari. Biar nggak ada O2 ya lingkungannya harus dibuat bebas oksigen dengan mengalirkan gas inert spt Argon.

Memangnya kalau ada oxigent apa pengaruhnya sihhh…..?

 

 

 

 

 

 

 

 

 

Apabila material tahan korosi memiliki surface yang mengalamai oksidasi maka otomatis keberadaan oxidasi ini akan menurunkan ketahanan korosinya sehingga diperlukan treatment lainnya untuk meningkatkan kembali sifat ketahanan korosinya. Namun ada kalanya hal ini tidak bisa lgi dilakukan karena acces terhadap object tersebut hanya dalam satu sisi. ( welding pipe ) Bagaimana cara menginfus / mempurging …?

Biasanya kalau dilapangan kedua ujung pipa diberi isolasi atau tape atau busa yang rapat pori porinya. Intinya nggak boleh ada keluar masuk udara sehingga oksigen tidak ada dilingkungan welding tsb. Ke dua ujungnya lalu diperi lubang untuk memasukkan gas Argon ( Nitrogen juga OK ) tadi. Setelah itu baru dialirkan gas argon dengan kecepatan yang perlahan sehingga tidak terjadi turbulences. Sampai dipastikan bahwa gas oksigen yang ada sudah keluar semuanya di dalam chamber purging ini. Biasanya banyak Ar gon yang terbuang karena pemakainnya nggak terkontrol dan yang memasukkannya juga nggak tahu dan mau cepat cepat selesai. Tugas Eng untuk memberikan masukan yang tepat terhadap penagliran gas ini. Sedangkan untuk daerah gap yang akan di weld juga harus di seal dengan bahan seal yang bebas dari halogen, karena unsur halogen spt clorine akan membuat material jadi britle. Beberapa project meminta oksigen content ( Oxigen indicator dalam ppm ) selama pengelasan material korosi ini untuk menentukan effectivitas dari purging.

Berapa kecepatan gas purging di perlukan…?

Berapa cepatnya kecepatan gas tergantung dari volume daerah isolasi purging. Biasanya bisa dengan memperkirakan kecepatan pengusiran oksigen dalam chamber. Dan juga harus dipastikan tidak ada kemungkinan gas dari luar mau masuk kedalam chamber.

BERAPA LAMA PERLU PURGING ?

 

 

 

 

Kalau kita mau mengelas pipa yang tebal yang mungkin bisa 30 pass apakah harus dipurging sampai cappinya…? Dalam beberapa teory welding ..purging cukup dilakukan sampai thickness weld deposit 8 ~ 12 mm dan ini tergantung juga dengan WPS dan lingkungan kerja yang terjadi selama pengelasan. Preheating untuk menghindari pembentukan chrome carbides dianjurkan dan kandungan sisa oksigen di bawah 100 ppm.

Kalau kita bisa mempurging dengan baik maka sudah pasti hasil pengelasan barang tahan korosi ini juga akan semakin tinggi qualitasnya… Kebiasaan dilapangan yang tidak peduli dengan quality karena ketidak tahuan, atau karena lack of Quality awareness dll harus dibuang.

Semoga bermanfaat.

www.hazwelding.wordpress.com

Melihat banyaknya equipment yang di gunakan di suatu system process ( refinery, Platform, FPSO, dll) kadang membuat kita bingung ini fugsinya apa , cara kerja gimana, dari mana, mau dikemanakan lagi. Sepertinya mengerti kimia proses dalam pengolahan crude oil, petroleum dll adalah sangat menarik sekali.

Tulisan ini dikirim oleh Cak Tris , mungkin sedikit memberikan gambaran tentang salah satu PV yang berfungsi sebagai Separator dengan lebih khusunya lagi type HLF ( horizontal Longitudinal flow ).

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The HLF is the most popular and versatile separator in the industry. Designed with a wide range of internals specific to each application, it is suitable for a full range of gas/oil ratios, pressures, and flow rates. The horizontal design offers the advantage of large gas/liquid and oil/water interfacial areas to speed the separation process.

 

 

 

 

 

 

 

 

 

 

 

How It Works

Like all separators, the HLF must perform four distinct functions – inlet momentum control, vapor demisting, liquid retention, and liquid outlet control.

Normally, the inlet is on one end of the horizontal separator, and the gas and liquid outlets are on the opposite end. As fluid enters, bulk separation occurs at the inlet device. The phases separate within the liquid retention section and flow to their respective outlets. Demisting and coalescing devices assist in the phase separation, and vortex breakers prevent the re-entrainment of phases.

 

 

 

 

 

 

Inlet Momentum Control

In the horizontal separator, several alternatives are available for controlling inlet momentum. Splash plates, dished heads, the Porta-Test Involute and the Port-Test Revolution™ are available from NATCO Group. The inlet device controls the inlet momentum by redirecting the inlet stream and dissipating the energy of the inlet fluid. The Porta-Test Revolution additionally utilizes the energy of the incoming fluid to eliminate foam.

Vapor Demisting

There are several options available for vapour demisting. Wire mesh, serpentine vanes and Performax® are all viable alternatives for removing the liquid droplets from the flowing gas stream. Performax® and serpentine vanes are normally installed vertically (perpendicular to flow) in the gas phase across the vessel diameter. The tortuous flow path of the devices creates an inertial separation mechanism. Wire mesh utilized in a separator may be installed in a horizontal position at the gas outlet for final cleanup. Wire mesh relies on droplet impingement and coalescence as the separation mechanism.

Liquid Retention

In 3-phase designs, oil and water separate in the liquid retention section. xxxxx elements are normally utilized to speed the liquid/liquid coalescing process. Sizing of the liquid section is normally based on retention time. The retention time required is heavily influenced by the crude oil gravity, the operating temperature and the required outlet BS&W. Sand jet systems may also be added in this section to allow sand removal from the vessel during operation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Liquid Outlet Control

The purpose of the outlet control section is to prevent re-entrainment of the separated phases. Several alternative configurations are available for 3-phase outlets – bucket and weir, bucket and riser, fixed weir, spillover weir and standpipe. NATCO can recommend the proper configuration for your application. Liquid and gas outlet vortex breakers are also typically included in this section. NATCO vortex breaker designs and placement focus on preventing vortexes from occurring.

 

Applications

Because of their versatility, horizontal separators are used successfully as production separators, test separators, gas scrubbers, wellhead separators, slug catchers, free water knockouts, degassing drums, flare scrubbers, inlet separators and floating production separators.

Performance

Horizontal separator performance is determined by the characteristics of the fluid being separated, the size of the vessel and the type of internals installed. In general, liquid carryover in the effluent gas stream will not exceed 0.1 gallons of particles larger than 10 microns per million standard cubic feet of gas if serpentine vanes are utilized for gas demisting. Performance is even better if wire mesh is utilized. To enhance oil/water separation in 3-phase separators, Revolution internals, perforated baffles and Performax® coalescing sections may all be added. BS&W content in the outlet oil stream can be significantly reduced with the inclusion of one or a combination of these items.

 

 

 

 

 

 

 

 

Sorce : natco

THE  PIPING  MATERIAL  ENGINEER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Posisi Piping Material atau Piping Engineer merupakan jabatan penuh tantangan dan memberikan harapan yang sangat bisa dibanggakan…

 

Please read it and meet the requirement and you have a chance to be expert with good remuneration packaged.

 

 

 WHAT IS A PIPING MATERIAL ENGINEER

 

The piping engineer, who is responsible for the quality of piping material, fabrication, testing, and inspection in a project and the major activities such engineers are expected to perform. This individual can be employed by either the EPC (engineering, procurement, and construction) contractor or the operator/end user.

 

Job Title

 

The piping engineer, the individual responsible for creating the project piping classes and the numerous piping specifications necessary to fabricate, test, insulate, and paint the piping systems, is titled either the piping material engineer or the piping spec(ification) writer.

 

Job Scope

 

Whatever the title, the piping material engineer (PME) is a very important person within the Piping Design Group and should be dedicated to a project from the bid stage until the design phase has been completed. He or she should also be available during construction and through to mechanical completion.

 

The lead piping material engineer, the individual responsible for all piping engineering functions, usually reports directly to the project lead piping engineer, and depending on the size of the project, the lead piping material engineer may be assisted by a number of suitably qualified piping material engineers especially during the peak period of the project. This peak period is early in the job, while the piping classes are being developed and the first bulk inquiry requisitions are sent out to vendors.

 

The Piping Material Engineer’s Responsibilities

 

The piping material engineer’s responsibilities vary from company to company. Here is a list of typical functions that he or she is expected to perform:

 

a.       Develop the project piping classes for all process and utility services.

b.       Write specifications for fabrication, shop and field testing, insulation, and painting.

c.       Create and maintain all data sheets for process and utility valves.

d.       Create a list of piping specials, such as hoses and hose couplings, steam traps, interlocks.

e.       Create and maintain data sheets for these piping special (SP) items.

f.        Assemble a piping material requisition with all additional documents.

g.       Review offers from vendors and create a technical bid evaluation.

h.       Make a technical recommendation.

i.        After placement of a purchase order, review and approve documentation from vendors related to piping components.

j.        When required, visit the vendor’s premises to attend kickoff meetings, the testing of piping components, or clarification meetings.

 

 

 Qualities of an Engineer

 

 

 

 

 

 

 

 

 

Not only is it essential that a piping material engineer be experienced in several piping sectors, such as design, construction, and stress, he or she must also be a good communicator, to guarantee that everyone in the piping group is aware of the materials of construction that can be used for piping systems. The PME must also have a basic understanding of other disciplines having interface with the piping, such as mechanical, process, instrumentation, and structural engineering. He or she should also be aware of the corrosion characteristics of piping material and welding processes necessary for the fabrication of piping systems. Both corrosion and welding engineering are specialist subjects, and if the PME has any doubts, he or she must turn to a specialist engineer for advice.

 

 

Experience

 

There is no substitute for experience, and the piping material engineer should have strengths in several sectors and be confident with a number of others disciplines, to enable the individual to arrive at a suitable conclusion when selecting material for piping systems. Strong areas should include piping design layout and process requirements. Familiar areas should include the following:

 

.  Corrosion.

. Welding.

. Piping stress.

. Static equipment.

. Rotating equipment.

. Instruments.

 

 

PIPING MATERIAL ENGINEER’S ACTIVITIES

 

Outlined here are the principal activities of a piping material engineer. These are listed in chronological order as they would arise as a project develops from preliminary to detailed design. The Piping Material Engineer

 

Development of the Project Piping Classes

 

All process plants have of two types of principal piping systems:  process (primary and secondary) piping systems and utility piping systems. Process piping systems are the arteries of a process plant. They receive the feedstock, carry the product through the various items of process equipment for treatment, and finally deliver the refined fluid to the battery limits for transportation to the next facility for further

refinement. Process piping systems can be further divided into primary process, which is the main process flow, and secondary process, which applies to the various recycling systems. Utility piping systems are no less important. They are there to support the primary process, falling into three groups:

 

·         Support—instrument air, cooling water, steam. .

·         Maintenance—plant air, nitrogen. .

·         Protection—foam and firewater.

 

There are other utility services such as drinking water. Piping Classes. Each piping system is allocated a piping class, which lists all the components required to construct the piping. A piping class includes the following:

 

. Process design conditions.

. Corrosion allowance.

. List of piping components.

. Branch table.

. Special assemblies.

. Support notes.

 

 

Source : Piping Material Guide by Peter Smith

 

To be continue in 2^nd post.