Piping & Fabrication

ICA PROJECT TAYAN ALMOST FINISH

2014-05-13T23:24:00.002-07:00

I think ICA PROJECT TAYAN almost finish, probably within one or two months again, this project will completely finish. Now the activity is only closing punch list and pre-commissioning, after all the activity complete, will be hand over to the owner, which is Indonesia Alumina Chemical (ICA).
My schedule leave this project is in the end of this month (30 Mei 2014), but I don't know if there is any revision of schedule, all is depend on the demand.

This is few pictures that Piping and Fabrication can provide, I hope this is enough to accomplish this Tayan Project.

Installation of Tetron Canvas Finish

Inspection of AL 4-6

All building / Structure almost Finish

Finally, thank you to all teams who make this project complete. Piping and Fabrication report from Tayan, West Kalimantan.

Another Adventure with Mechanical and Project Control Now

2013-09-13T17:31:00.000-07:00

Finally now I join with WIJAYA KARYA (WIKA) company, after resign from Tsukishima Kikai, Co.Ltd. It's been a long time that I never update or posting this blog because there is no chance for me to do it. My activity at site with TJO really taking all of my time, but now after I join with WIKA, I hope I can continue to posting this Piping & Fabrication, at least once a week.

Now my position is Project Control, my job is too check and close every critical priority point, monitoring and reporting all activity at site, in ICA CGA Project Tayan. Everyday I have to check the condition at site, is it running as schedule or not, and if there is any problems, I have to report and coordinate with Person In Charge.

Now, I hope Piping and Fabrication will try to On Air again, even only become my personal journal, but there is no problem with it, Thank you.

Alignment of Vacuum Pan Filter

2013-02-16T19:17:00.000-08:00

It's looks I really don't have times to post this Piping and Fabrication blog, because working with Japanese really make me don't have times to do this. But, because this sunday and I request not to work on Sunday, so now I have chance to post this Piping & Fabrication.

Today I want to talk about the latest jobs that I work on it. Now I've been working on Vacuum Pan Filter on CHF Building with BOKELA Supervisor. Now we entering stage of alignment process of Bottom Plate, and that's really hard to do, because we have to make sure that Bottom Plate is really flat, no gap.

I think we probably will finish alignment process today, because BOKELA and WIKA now work on Sunday, and after that, we will continue another steps which is repairing the CHF Structure just to make sure that Discharge Chute will be fit enough to entering the Structure.

And Piping and Fabrication will always monitoring on every stages of the process.

New Project on Indonesia Chemical Alumina (ICA)

2013-01-14T21:57:00.001-08:00

It's been almost a month that Piping and Fabrication doesn't post, that because Piping & Fabrication have to prepare and learn so many thing in this New Project on Indonesia Chemical Alumina Project at Tayan, We`st Kalimantan.

Beside mechanical, I also have to supervise and monitoring civil work such as foundation, concrete, grouting and any other things. and I'm also learn a lot of thing here, thanks to Mr. Shimoda and Mr. Aoyagi from Tsukishima Kikai, Co. Ltd, Japan. They really help me much and that's really make me feel glad, because now my knowledge about Mechanical, Piping and Construction is increase.

And in next post I will add few pictures of this new project, but now I have to leave because my lunch time is

One More Step Become Mechanical Engineer

2012-12-16T23:28:00.001-08:00

I really feel so glad that I'm already first Interview in Jakarta with Tsukisima Kikai PT, and this week I will proceed my second interview in Pontianak and I hope I can pass this interview too, insya Allah. By the way Piping and Fabrication would like to say thank you to Mr. Sugeng Riyadi because he already give me a chance and opportunity to get this job and don't worry I will keep the promise.

And to the visitor of this blog, Piping and Fabrication will continue posting, of course I will post about my job which is Mechanical and Piping, and I will also attached more pictures, because I need that too as my documentation. Don't worry there will be more and more information that I will gave to all of you.

Once again, thanks to all of you who already supporting me.

My Last Duty on Water Treatment Project Line 5

2012-12-06T22:15:00.000-08:00

This is probably the last job for me on Water Treatment Project Line 5, because my contract will end this month, and maybe I will find something new or new job. I don't know, maybe to another region or another province, but that's doesn't matter at all.

Piping and Fabrication will always on and ON, because I really like to share all the knowledge that I have to everyone, and that's why I will always love to blogging on Piping and Fabrication and my other blog.

To everyone who already supporting me, especially my team and all my friend, it's nice to work with you and forgive everything I've done if there is something wrong with that and I will miss you friends.

Flange End Connection

2012-11-23T18:35:00.002-08:00

Today, Piping and Fabrication will talk about Flange-End Connection and I hope this topics will helpful for anyone who looking for knowledge about Piping System.

Flange Types

The flange-end connection defines the way in which it is attached to the pipe. The following are commonly available standard flange end types:

Weld-Neck (WN) Flange. Weld-neck flanges are distinguished from other types by their long, tapered hub and gentle transition to the region where the WN flange is butt-welded to the pipe. The long, tapered hub provides an important reinforcement of the flange, increasing its strength and resistance to dishing. WN flanges are typically used on arduous duties involving high pressures or hazardous fluids.

The butt-weld may be examined by radiography or ultrasonic inspection. Usually, the butt-welds are subject to visual, surface, or volumetric examinations, or a combination thereof, depending on the requirements of the code of construction for piping or a component. There is, therefore, a high degree of reliability in the integrity of the weld. A butt-weld also has good fatigue performance, and its presence does not induce high local stresses in the pipework.

Socket-Weld (SW) Flange. Socket-weld flanges are often used on hazardous duties involving high pressure but are limited to a nominal pipe size NPS 2 (DN 50) and smaller. The pipe is fillet-welded to the hub of the SW flange. Radiography is not practical on the fillet weld; therefore correct fitting and welding is crucial. The fillet weld may be inspected by surface examination, magnetic particle (MP), or liquid penetrant (PT) examination methods.

Slip-on Flanges. Slip-on flanges are preferred to weld-neck flanges by many users because of their initial low cost and ease of installation. Their calculated strength under internal pressure is about two-thirds of that of weld-neck flanges. They are typically used on low-pressure, low-hazard services such as fire water, cooling water, and other services. The pipe is ‘‘double-welded’’ to both the hub and the bore of the flange, but, again, radiography is not practical. MP, PT, or visual examination is used to check the integrity of the weld. When specified, the slip-on flanges are used on pipe sizes greater than NPS 2½ (DN 65).

Composite Lap-Joint Flange. This type of flanged joint is typically found on high alloy pipe work. It is composed of a hub, or ‘‘stub end,’’ welded to the pipe and a backing flange, or lapped flange, which is used to bolt the joint together. An alloy hub with a galvanized steel backing flange is cheaper than a complete alloy flange. The flange has a raised face, and sealing is achieved with a flat ring gasket.

Swivel-Ring Flange. As with the composite lap-joint flange, a hub will be buttwelded to the pipe. A swivel ring sits over the hub and allows the joint to be bolted together. Swivel-ring flanges are normally found on sub–sea services where the swivel ring facilitates flange alignment. The flange is then sealed using a ring-type joint (RTJ) metal gasket.

Blind Flange. Blind flanges are used to blank off the ends of piping, valves, and pressure vessel openings. From the standpoint of internal pressure and bolt loading, blind flanges, particularly in the larger sizes, are the most highly stressed of all the standard flanges. However, since the maximum stresses in a blind flange are bending stresses at the center, they can be safely permitted to be stressed more than other
types of flanges.

Waiting for Raw Water (Actiflo) Pic. 1 Re-Start Again

2012-11-18T16:30:00.000-08:00

It's been too long for Piping and Fabrication to wait Raw Water Line drawing 1 to continue again, there is still much work to do on Raw Water Line, including huge pipe size which is DN800 or 32 inch that we have to fabricate and erection.

Below here is an isometric drawing for Raw Water Line and almost 70% from that line is not finish yet, and we hope we can have enough man power to finish those line.

Isometric for Raw Water Line drawing No. 1

Can we finish those line in time? we hope we can do it, it's up to many circumstances, technical or non technical situation.

This is Piping & Fabrication write for you all just for information and share. Thanks for visiting!

THE PROCESS OF JOINT INTEGRITY

2012-11-11T16:39:00.001-08:00

THE PROCESS OF JOINT INTEGRITY
This is what we want to see and this is also what Piping and Fabrication mean to keep ON AIR until now, to provide us with valuable information like this, enjoy it.

To assist in managing a process, ask yourself the following questions: why, what, who, and how? Why do we need a Flange Joint Integrity program? This was addressed in the previous section, ‘‘Cost of a Leak.’’ The stakes are enormous. A Flange Joint Integrity program will help improve plant safety and reliability while reducing its environmental impact. What do we need to control? The operating environment, the components, and assembly all need to be controlled. Who do we need to control? The designers, field operatives, and supervisors. How do we control? Train personnel to required competency. Design components using latest engineering standards. Develop best practices for assembly and maintenance. Implement a quality assurance program that provides traceability and ensures compliance to specifications. There are over 120 variables that affect flange joint integrity. These can be controlled through the following categories:
● Environment (internal and external)
● Components
● Assembly

The internal environment outlines the design and operating conditions of temperature, pressure, and fluid. With the external environment, consideration is given to location of the flange, whether it is operating in air or sub-sea, and externally applied piping loads. An understanding of the environment is crucial to the design and selection of the appropriate components with the correct assembly methods. The components include the most appropriately designed and selected flange, gasket, and bolting, commensurate with the risk dictated by the environment. Assembly includes checking the condition of the components and proceeding according to established procedures. Proper assembly requires that
● Flange faces meet the standards
● Gasket-seating stress is achieved
● Bolts, nuts, and gaskets are free of defects
● Appropriate lubrication is used

Execution requires trained, competent people using the correct tools and following procedures.

Thanks for Visiting Piping and Fabrication and see you always.

Fabrication Practices which is Cutting and Bevelling

2012-11-07T17:04:00.000-08:00

Fabrication Practices

Now Piping and Fabrication will start again to write about all what we need in Piping System, and now we entering with Fabrication Practices which is Cutting and Beveling.

The methods of cutting plate or pipe to length can be classed as mechanical or thermal. Mechanical methods involve the use of saws, abrasive discs, lathes, and pipecutting machines or tools. Thermal methods are oxyfuel gas cutting or electric arc cutting. Oxyfuel gas cutting is a process wherein severing of the metal is effected by the chemical reaction of the base metal with oxygen at an elevated temperature. In the cutting torch, a fuel such as acetylene, propane, or natural gas is used to preheat the base metal to cutting temperature. A high-velocity stream of oxygen is then directed at the heated area resulting in an exothermic reaction and severing of the material. Oxyfuel gas cutting is widely used for cutting carbon steels and low alloys. It does, however, lose its effectiveness with increasing alloy content. For higher alloy materials, some form of arc cutting is required. Plasma arc cutting is the process most frequently employed. It involves an extremely high temperature (30,000 to 50,000°K), a constricted arc, and a high-velocity gas. The torch generates an arc which is forced to pass through a small-diameter orifice and concentrate its energy on a small area to melt the metal. At the same time a gas such as argon, hydrogen, or a nitrogen-hydrogen mixture is also introduced at the orifice where it expands and is accelerated through the orifice. The melted metal is removed by the jetlike action of the gas stream.

Because oxyfuel gas and arc cutting involve the application of heat, preheating may be advisable in some cases. Weld end bevels can also be prepared by the mechanical or thermal methods just described. Both mechanical and thermal methods are used to apply the V bevel, which is used in the vast majority of piping applications. For compound and U bevels or those which may involve a counterboring requirement, horizontal boring mills are most appropriate. Various factors to be considered in selecting a weld end bevel are discussed in the section, ‘‘Welding Joint Design.’’

Finished Hydro Test for Sand Filter or Multigrade Line

2012-10-31T23:37:00.000-07:00

Finally we can completed the Sand Filter Line with finished Hydro Test 10.7 Bar. Piping and Fabrication just want to inform all of you that Sand Filter Line is Done, just few more Joint to the Suction Pump and we plan that will finish fabrication and install in this week.

10.7 Bar Pressure on Hydro Test Display on Pressure Gauge at 14.45 WIB

Pressure still remain 10.7 Bar on the one hour Holding Time

And now we can focus to the Additional Work for WTP Project such as Fill Softener Tank with Resin, Modification Frontal Piping on Softener Tank, etc.

We never boring to Thanks to the teams and anyone who get involves in this WTP Project. Congratulations Teams, We still have Raw Water Drawing 1 waiting to get our touch.

Evaluation for Water Treatment Project

2012-10-21T02:30:00.002-07:00

In the end of Water Treatment Project for all the lines such as Filter Water, Soft Water, Raw Water, Sand Filter, Dynasand and etc, including all the Equipment or Tank, Multigrade Tank, Softener Tank and Demin Water Tank, there is so many thing we can learn from that project.

It's really hard to control people or can we call Man Power, because we have a big hope to them, when we hire them, they will do as professional worker, but the fact is we have to make them work, teach them how to work, and told them how to work and that's really such a big problem for me and my team. But, we have to take that responsibility, because we can't hire another worker, they all the same, mostly they can't work especially helper.

Luckily that we had very competent and good leader, so they can arrange all that worker, even we know that's really hard but we have to use them. Not mention the users want to do this, want to do that, like they never know the problem on the field, everything can goes wrong if we push them too much.

Piping and Fabrication only hope everyone will understand that we already work as maximum as we can, as hard as we can and we can do nothing more than it, this is the best what we can do for now. We hope, we really hope.

Thanks for everyone who supporting us to finish this WTP Project, especially my teams, once again thank you very much.

Soft Water Line is Done

2012-10-17T20:41:00.001-07:00

Same like Filter Water, Raw Water and Dynasand, Soft Water is Done and we already finish Hydro Test for Soft Water too. Piping and Fabrication will inform this to all of you just to inform to anyone who involve with this process.

But, still there is still plenty of work that we must done in short of time, next is Sand Filter and Softener Tank. Under my supervise and Mr. Fandi, we will try to finish Softener Tank this week, because next week all line has to running to supply water for Fiber Plant Line 5.

Once again, thank you to everyone who involve with this project and of course my team, congratulation Teams! I don't know how to thanks to all of you, because I've seen myself that Soft Water Line drawing is really different with actual site condition, there is too many modification we have to do, such as cut and re-weld, different size, different elevation, etc.

Filter Water Line is Completed with Successful Hydrotest

2012-10-06T20:17:00.001-07:00

I know it's been a little bit late when I inform this, because probably it's almost few weeks ago that Filter Water Line is completed. We are glad that we can finish the Filter Water on time, of course with much help from my teams and the others. Without them, we are nothing. Filter Water Line completed with Hydro Test process with almost 11 Bar Pressure and we found no leakage.

Here it is the pictures of Hydro Test, we start from 16.45 to fill the water in, and at 17.50 the pressure start stabilize and we start holding time about 1 hour and finish about 19.00 WIB. This is Piping and Fabrication Reporting.

Pressure at 11 Bar for Filter Water Hydro Test

Starting Holding Time at 17.50

Filter Water is Completed

Once more we are thanks to someone always helping us which is Mr. Pandi, because he always lead us and warn us if there is some problem with our job, and of course to my teams, Congratulations Teams!

Replace DN1400 Outlet Dynasand with The New One

2012-10-03T05:16:00.000-07:00

May be this DN1400 Outlet Dynasand it's too old, too many corrosive and need to be replace with the new one, and on the Water Treatment Plant (WTP) Project, Replacing DN1400 Outlet Dynasand is one of the line that we have to finished as soon as possible.

Piping and Fabrication has few pictures when we replacing the Old DN1400 Outled Dynasand with the new one, smaller but more effective. And also thank you to everyone who involves with this job and once again thank you very much.

DN1400 Outled Dynasand (previous)

Erection DN800 Pipe Outled Dynasand (Processing)

DN800 to DN600 Outlet Dynasand (New One)

I hope all the line can finish on time without any major problem. Thanks for visiting and good luck!

All The Line on WTP Project has to Finish on 15 October 2012

2012-09-28T20:23:00.001-07:00

Bad News for our team, WTP Team, we have to finish all the Line, including sand filter and soft water line at October, 15, 2012, and that's really make me and my teams have to think and work faster. Piping and Fabrication try to find the solution for this situation, and we really hope that we can finish this project on time.

Not mention I have another instruction that the Raw Water Line need to revision again, because we have to follow the process department with they new ultrasonic flow meter. And also they want to finish the revision only on three days and I just can hope there will be no Re Hydro Test for that line.

Completed Line Raw Water Drawing 1 & 2

2012-09-18T19:21:00.001-07:00

Finally we completed Raw Water Line for Drawing 1 & 2 (Inlet Actiflo), and we also already completed Radiography, Flushing and Hydro Test for the line. Me and My Team finished this Raw Water or Actiflo Line in time, even we know there is still a few problem during that process but, finally we made it. Thank you to anyone who get involve with this job and this is few pictures and photos when Piping and Fabrication doing Flushing and Hydro Test.

Flushing Process

Hydro Test at 10.7 Bar Pressure

And the good news is, there is no leakage found during that process and Congratulation Teams!

How Can I Finish This WTP Project?

2012-09-13T19:29:00.001-07:00

That's the question that I want to ask to my Boss, because I can't get enough tools, enough man power and enough times to finish this WTP Project on times. Not mention all the tank and equipment that we have to setting up in the same times. That's why me and Piping & Fabrication will talk to the boss and make decision to add more tools, man power (quality man power) and also all the facility I need.

I think that's the only way to get this project finish on time or the company will loose much money and times if the project delay or can't finish in time.

ERECTION MULTIGRADE (SAND FILTER) TANK

2012-09-07T23:01:00.003-07:00

Finally Multigrade Tank arrived in the SPV Plant and me and my team can start erection the tank. Because if this multigrade tank not finish erection yet, the others job will be delay by it. And Piping and Fabrication show the pictures of the process of Multigrade Tank when it erection, put the tank on the base.

Piping Erection for Filter Water Line

2012-08-20T20:49:00.002-07:00

Continuing again with WTP Project, and now at Demin Plant, we doing Piping Erection for Filter Water Line. It’s really hard place to do the piping erection, because we do this erection inside Demin Plant building and we only have small space and we can’t make any mistake. Because if something goes wrong, the existing pipe and tank will crush by that pipe.

Manually Piping Erection at Demin Plant

With a very little space between the wall and existing pipe and tank,

we have to do piping erection manually

So we really have to extra carefully in this process, and Piping and Fabrication believe that our man can do this one, because they have experience for this kind of situation.

The planning is, after we complete all this Filter Water Line, and all the support and civil work is complete also, we will make this team to do the erection in the same location with another line, which is Soft Water Line, but we still waiting for that time, and I hope that will happen soon.

Water Treatment Project Still on The Way

2012-08-15T18:55:00.000-07:00

After almost a few months Piping & Fabrication not posting, because of the Water Treatment Project (WTP) is still on the progress, so I can't do much on the office, cause I have to supervise and control the project and make sure that project is running well.

After almost more than a month, our WTP project is already reach 46% from total 12000 inch dia, and it still doesn't make me happy because we don't have enough worker to do that project (less workers). But, on the other side Piping and Fabrication feel so happy that we can prove to everyone, even we only have no more than 20 persons, but we still can reach more than 45% until now.

So much people doesn't believe that me and my team can do the WTP project in time, but we already prove it to anyone that we can do it and silent them with that progress.

and for everyone, Minal Aidin Wal Faidzin (Mohon Maaf Lahir dan Bathin). Thank you very much.

Catch the Progress on the Pipe Rack Line 5 Progress

2012-07-10T02:16:00.001-07:00

It's been almost a month since Water Treatment Plant Project Line 5 is start, and it's really takes a lot of times and energy for me. While the other project which is Pipe Rack Line 5 is almost reach the Dead Lines and that means all the water lines has to hand over to the users in July, 25, 2012, and that's mean we only have few weeks to finish all the water lines in the pipe rack line 5.

Piping and Fabrication now will talk about what is the problems on this pipe rack line 5 project, and how can we solve all the problems? After we had a meeting with all the leaders, including staff from the center office, we decide that all the critical lines must be start with special teams and all the requirements for them we have to provide everything what they wants, including consumables, equipment and even transportation to mobilize the material to the site.

So, I have to send two welders on WTP Project to Pipe Rack, because they are also need more welders to complete the task "On Times". Even now I have to think harder, how do I have to catch the progress with less welders? I hope there is another solutions for me and my teams, also for Pipe Rack teams.

ERECTION PIPE AT WATER TREATMENT PLANT

2012-06-15T05:31:00.000-07:00

This is really exhaust day to all of us at site project, including myself. with Piping and Fabrication, I will share the experience when me and my team has to finish Shutdown with only four hours limitation, because the machine will running again.

With all the preparation that we already prepare about few days ago, everything almost run according to the schedule, except in few line that I have to cut and re-weld pipe line DN300 because it's not has good gap to weld. And when we have to finish all the line with 4 hours left, so we do anything necessary to finish the job so the plant can running again.

I know this experience with Erection Pipe at Water Treatment Plant during Shutdown will never forget, because we have small bonus from the users and that's make me and my team work as harder we can do. and here it is few pictures when we do the erection pipe DN300 and install valve at Water Treatment Plant.

Erection Pipe

Cut and Re-Weld Pipe

The Pipe has been joined

That's all what Piping and Fabrication can told about Erection Pipe at Water Treatment Plant during 4 Hours Shutdown.

Urgently Job for Hot Tapping at WTP Project

2012-06-05T05:46:00.002-07:00

I know this is too hard for me to do it myself, not even if I have to do with my teams but if there is no equipment and mobilization for our teams, it's impossible to finish this WTP Project on time. Not mention for Hot Tapping Job, it's really urgent, because we can't stop the machine or request for shut down, that's will stop all the production process.

And with all the Piping and Fabrication job about 12 thousand Inch Dia, I think I have think another strategy for this WTP Project. Including all the report and material issue that has been delayed for few days. But, I believe this will get better soon, same as like Pipe Rack Project. I hope.

TUBING

2012-05-27T00:22:00.003-07:00

Like Piping and Fabrication said in the last post, that will provide another useful post and now we entering chapter of Tubing.

Copper, aluminum, steel, and stainless-steel tubing are frequently used in hydraulic, pneumatic, and sampling systems. Installation is most often concerned with protection of such materials from damage, since they are often associated with control systems. The manner of protection is left to the designer’s judgment. Lighter wall tubing is often bent using small compression-type benders. Tubing is joined to itself and to pipe-size fitting and components with a variety of proprietary tubing fittings.. Some heavier-wall stainless-steel tubing is welded using specially designed socket welding fittings, GTAW welding with filler metal added is used for such applications. Pipe Supports This section offers some thoughts on the installation of piping supports. The design, manufacture, and influence of supports on the system flexibility.

As pointed out earlier, economics and efficiency dictate that it is preferable to install the permanent supports for a system as the first step, thus minimizing the need for temporary supports. In so doing considerable judgment should be exercised, since there can be minor variations between the as-designed and as-installed line location. Resilient and constant-effort support should be locked with stops to preclude change in supporting effort as the line is being installed. Only after the line has been completely welded, tested, and insulated should the stops be removed. Once removed, the resilient and constant-effort supports should be carefully adjusted to their ‘‘cold’’ positions. This may take several iterations, since adjustment of any one will change the loading on the adjacent ones. Systems with multiple constant-effort supports can be especially troublesome. Since the support design is most often based on theoretical values of weight of the pipe, insulation, and the fluid, there will be some difference between the actual and calculated supporting effort. Where rigid supports are involved, this variation will be taken up automatically. Where a system is designed with multiple resilient or constant-effort supports, every effort should be made to incorporate one or more rigid supports in the design to absorb the variation between actual and theoretical loads. Otherwise it may be necessary, with the approval of the designer, to modify the spring load-carrying settings. As the line goes to operating temperature, it should be carefully observed to assure that there are no unforeseen interferences with its required expansion, particularly at nearby structures, floor sleeves, or adjacent lines or by restrained branch connections. Some modification may be required to assure free expansion of the line. All resilient supports and constant-effort supports should be checked during initial start-up to assure that they are functioning properly, and after the line has been at operating temperature for several hours, they should be checked to verify that they are in the required ‘‘hot’’ operating condition. It may be necessary to readjust some units to match the calculated ‘‘hot’’ loading. These settings should be checked on a regular basis for the first few weeks of service, particularly in systems operating in the creep range, since the temperature will begin to relieve locked-in construction stresses, and the line may choose a different, more relaxed location. Readjustments may be required. If after some time in service, the resilient and constant-effort supports still require significant adjustment (i.e., the system cannot be balanced), a complete review of the flexibility analysis, expansion calculations, weight calculations, hanger, design, and installation procedures should be made to determine the cause. Resilient and constant-effort support units which are not functioning in the spring range (i.e., they have become ‘‘solid’’ or ‘‘loose’’) may impose undesirably high stresses in the line if they are not corrected, which can lead to premature failure or significantly reduced system life.

Leak Testing

At one time, complex shapes were pressure-tested to determine their suitability for the service intended. This involved stressing the component to a point above service stresses, but below bursting stress, and was referred to as a pressure test. Currently most codes require some type of test to determine leak tightness rather than service suitability. The most common method of leak testing for piping systems is the hydrostatic test. Usually this involves water at ambient temperature as the test medium. B31.1 requires that the system be pressurized to 1.5 times the design pressure, ASME III, to 1.25 times the design pressure, and B31.3 requires a test pressure of 1.5 times the design pressure adjusted by the ratio of the allowable stress at test temperature divided by the allowable stress at operating temperature. In each case, however, the test pressure of unisolated equipment or some function of the yield stress of the line material may be a limiting factor. See the applicable code for particulars.

The line must be held at test pressure for at least 10 min, but may be reduced as permitted in the applicable code until the examination for leakage is complete. Depending on the specific situation, alternative test fluids may be employed. As an example, in a liquid sodium system, where water could be very hazardous, or in cases where the possibility of freezing exists, a hydrocarbon or other fluid might be used.

In instances where water or other liquids are unacceptable, or where supports may not be adequate to carry the added weight of water, pneumatic tests may be performed. Pneumatic tests are potentially more dangerous than hydrostatic tests, and extreme care should be exercised. B31.1 and ASME III require the pneumatic test be performed at not less than 1.2 times the design pressure, while B31.3 limits the test to 1.1 times design. In each case, the limits regarding equipment and yield strength previously cited for hydrostatic tests also apply. Prior to the test a detailed review of the section of the line to be tested should

be made with the following in mind:

1. Temporary supports for those sections where the permanent supports were not designed to take the additional weight of the test fluid.

2. Isolation or restraints on expansion joints.

3. Isolation of equipment or valves which may be overstressed at test pressure.

4. Location of test pump and the need for additional test gauges if there is a significant head variation due to elevation differential.

5. Location of vents and drains.

6. Location of a relief valve to preclude excessive overpressure due to possible thermal expansion of the test fluid.

7. Consideration of the probable ambient test temperature relative to the expected brittle fracture toughness of the system materials. Heating the water may be a solution.

8. Alternative test fluid.

9. Accessibility to the weld joints for inspection. Some codes require that the weld joints be left exposed until after the test.

10. Assurance that no part of the system will exceed 90 percent of its yield strength.

It is advisable to prepare a written procedure outlining the scope and boundaries of each test to assure that it is performed in a safe manner. The codes vary a bit on the required test pressures, time at test pressure, pressure during inspection for leakage, and whether alternative tests may be performed. It is advisable to look at each one specifically.

That's all for now about TUBING and thanks for visiting Piping & Fabrication.