Poppy and the Steam Forum and Power Forum

Welcome to the steam and power forum, a bulletin board dedicated to questions and answers to Steam Plants and Power Generation Plants for steam boilers, turbine generator and heating problems. Dedicated to power plants, power generation, supercritical, and heating plants as well as steam boilers, steam turbine generators, gas turbines or combustion turbines, hrsg, steam heating, pressure vessels, steam line, including ASME questions and more. Remember the forum is made up of volunteers from experts to beginners. Unfortunately, we cannot allow free commercialism that promotes products, services, or sites.
 
The Steam Forum and Power Forum is being sponsored by the following:
Industrial Training School - Main Distant Learning
 

Poppy   Steam Forum  

Internal cracks on Boiler Steam Drum

Friday, January 28, 2011   By: Gerardo Chiapetta [1106] 1 Stars
We have a Mellor Goodwin Boiler currently in major outage. We are replacing almost all the internal tubing, insulation, repairing gas and intake air paths, etc.
During Drum inspection, several cracks have been found, and some of them already repaired. But theres particularly one indication found obtained through UT test that show a circumferential internal not superficial crack? Its located near the union welding of head to shell. Im attaching our reports and some photographs of the findings. The drum is 100 mm thick and the indication is 25 mm below internal surface.
Some say it has been there since the drum was built 1968 others say it could be an internal crack that could get worse in the future.
Now we are in the repairing dilemma. Should be left like that in order to avoid additional damage to the drum or should it be repaired?

Has anyone had some experience or event similar in your boilers?

Picture

Click on picture for full size view or to view PDF!

Post a Reply...
Viewed 560 times

Friday, January 28, 2011   By: Gerardo Chiapetta [1106] 1 Stars
Sorry, but the files are in Spanish hope you can help!
Regards,

Gerardo.

Post a Reply...
Viewed 596 times

Monday, January 31, 2011   By: Murphy [21] 4 Stars
I would like to add that a discontinuity that you found linear or round that you reject must be removed for the benefit of all. As a level-II UT NDT non-destructive testing Technician your judgment is the most important.

I agree with Ross that using radiography is very useful if it is available in country.

But if it is not, then asking for a second Ultrasound Level-II or Level-III will prove your first set of results. Certainly those in the power plant will not be convienced.

The risk of leaving the rejected discontinuity in the drum at the circumfrential joint is very-very high.

I would have the areas of interest excavated and arrange for heat treatment for the repair weld procedures .

I would guess that the boiler repair firm holds an ASME code S stamp.

Post a Reply...
Viewed 569 times

Friday, January 28, 2011   By: Ross [390] 5 Stars
I would have thought that an internal weld problem suggest it was there a long time but that does not make it okay to leave. I am thinking how we would handle it.

I am not a weld inspector but my experience is that could be a lack of weld fusion. You are in a tough spot and should tell them how you are going to classify the indication.

We would repair by grinding it out or air arc it out.

The owner will have to deal with the PWHT stress relieving.

Post a Reply...
Viewed 568 times

Friday, January 28, 2011   By: Ross [390] 5 Stars
Almost forgot. We would have an x-ray done.

Post a Reply...
Viewed 570 times

Sunday, January 30, 2011   By: N.Ramani [965] 4 Stars
Hope you would have checked the whole Drum since this could be a problem of lamination. As advised by others you cannot leave it as it is. I would suggest that you get in touch with EPRI of USA or any reputed Boiler manufacturers who could help you.

Post a Reply...
Viewed 559 times

Tuesday, February 01, 2011   By: Ross [390] 5 Stars
Are the repairs to the steam drum almost done or did the owners opt out not to repair?

Post a Reply...
Viewed 567 times

Tuesday, February 01, 2011   By: Gerardo Chiapetta [1106] 1 Stars
An x-ray was made last friday. A D7 plate was used and exposure was for about 4 hours. The x-ray didnt show anything, no indication or crack at all. An ASME consultant suggested that if the x-ray result didnt show anything, the code follows x-ray results and not UT... Its something obvious, he suggested not to repair but he wouldnt sign a paper! If he had to sign anything he would suggest to repair... Its kind of confusing right?
So, the managers and owners decision was taken: not to repair, continuing mounting tubes and keep monitoring the drum yearly. I dont quite agree with this decision but its their word, it would have taken 2 days to repair or so... Anyways, thank you all for your help and suggestions.

Regards,

Gerardo.

Post a Reply...
Viewed 554 times

Tuesday, February 01, 2011   By: Ross [390] 5 Stars
I am surprised the consultant would not agree when at least an RT Level-ll NDT tech looked at the x-ray and evaluated. Remind me not to suggest him.

Post a Reply...
Viewed 576 times

Sunday, February 06, 2011   By: Murphy [21] 4 Stars
Having RT done on the steam drum was the best decision and when the film shot does not show an indication the decision seems sound.

Whether round or linear and using the same acceptable criteria of ASME Section One and Section -Nine as well as that of Section Five to that to which the boiler was built.

When a Level-3 RT establishes a written procedure for the shot then after developing there is no indication then there is no indication.

But, it does not invalidate the UT especially since it is repeatable. My impression is UT found a micro-structure anomaly perhaps at the heat effect zone at the weld to base metal interface from when the head was welded to the tube sheet of the steam drum shell. Perhaps the tube sheet was to cold?

Post a Reply...
Viewed 591 times

Published on steamforum.com

 

Featured
superheated steam ideal gas
By: cmolanes@itba.edu.ar [50]

Mr. Pradeep:

Steam behaves well as an ideal gas if not too close to the saturation line if you place yourself on a Mollier chart, when the temperature and enthalpy lines coincide and are straight, horizontal lines, then it behaves as ideal, and this you can easily see on the chart.

I would rely though most on the steam values given by the chart or steam tables, because they are confident independently of the region , e.g. they stand both for ideal and real gas, but the ideal gas equation ....   Read All
Advertising Info - Click Here!

It's hard not to look at this ad at least once, then you go to the next page an notice it again. Maybe you will not read the message, but you will be thinking about the brand and we call that brand impressions.

About 2/3 of internet traffic is useless traffic and consist of malicous-bad-robots.  However, there are good robots too.  We block bad-robots, and allow the good one's through, but we just do not count the good one's.  We want good straight-brand impressions for our advertisers!

Imagine your static or animated display advertisement placed here, and if that is not enough you can include text too to expound on the virtues of your services and or products.    In addition, you can benefit by using our new advertisement feature to have your video included in your ad space.  Wow, make an infomerical with text and a display by combining all features to enhance the readers or audience's experience using your brand.  Ads can be much more than a static display ad. Here is an example of how your video could be used or position in this ad space:

 

Caption: This public domain video shows from Nationawide Boiler and they are the first to provide a 1000-BHP trailer mobile rental unit using a Superior Boiler.  The author of the video is not an advertiser and is being used to show how the video ad can be of value to the reader since you have already being viewing the video.  It is hard not to think about the authors brand after viewing the video ad.  This is the benefit of Branding.

 

 

 

A Long-Game that Earns Tomorrow's Sales


Click on this Promotional Advertisement to Contact Us Today!

Good Branding Puts Your Brand or Company in the Front of a Decision-Maker’s Mind for a Purchase either Months from Now or Five-Years in the Future.

Good branding makes your brand or company the leader in a crowded field of other brands or companies vying for your potential or existing client's attention. 

An invitation to the buyer's table to negotiate potential sales from $thousands to $millions of dollars in any of these: Systems sale, Capital Equipment, Upgrades & Modifications,  Repairs, or Capital Project becomes easier now with a recognized brand that thinks forward by brand advertising.

Your advertising will cost you an unbelievable low amount, so ask for our Media Kit that has Specs and Rates. 

Below is some of our demographic data for steam and power forum users will speak for itself:

Bus Sector Percent   Education Percent
Manufacturing 11%   College 51%
Power Gen 20%   Grad School 20%
Chemical & Petroleum 15%      
Medical Facilities 6%      
Pulp & Paper / Forest 7%      
Pharmaceutical 7%      

Our network works hard for you with placements for full coverage on part of the network, or full network placement.  Brand yourself today and don’t miss-out on being invited to your client or future client's table because they forgot you.  Be the leader they will remember and be part of their capital project.  Tomorrow’s clients are your future.

 

Advertising and Marketing Agency for the steam and power forum
PE Marketing, LLC

Branding.jpg

Sponsors/Advertisers
Industrial Training School
 
Industrial Training School - Maintenance
 
Industrial Training School
 
National Assoc of Stationary Operating Engineers
 
Confidentiality, Disclaimer; Policy
STEAM and POWER FORUM
© 2001 to Steam Forum, All Rights Reserved.
PE Marketing LLC is representing the steamforum for advertising and marketing
Valid XHTML 1.0 Transitional