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  

Increase in Wheel Chamber Pressure

Friday, December 16, 2016   By: Bonga [2008] 0 Stars
Hi Guys,

I would like to hear your views on the factors or variables that are the major causes of the increase in Wheel Chamber Pressure of a Steam Turbine. To give you some background, we have experienced an increased in Wheel Chamber Pressure of our Turbine condensing. It was concluded that the root cause was fouling.

I have, however came across a report that says in 2013 shutdown of the machine, the nozzles were found to have been worn out although there is no quantification, it was recommended that we replace the nozzles in 2015, which didnt happen.

The condenser pressure is also 10kPa off from design.

Turbine has been shut down for a wash with condensate but the most recent wash, nothing was found in terms of salts.

Is there other things that we can look at?

What are your views on worn out nozzles and as well as poor vacuum on the condenser? Will vacuum have significant impact on wheel chamber pressure? Does fouling have more impact than worn nozzles and poor vacuum?

Is there any material you can also recommend for me to read?

Many thanks in advance.

Post a Reply...
Viewed 3705 times

Saturday, December 17, 2016   By: cmolanes@itba.edu.ar [50] 4 Stars
Dear sir:

I cannot give a complete answer, but I can afford some tips... at first glance, if there is a lack of vacuum, e.g. due to defective air ejection or lack of enough cooling water flow, then the pressure will certainly increase at the turbine exit, impairing the power obtained because the enthalpy drop will be less.

Worn out nozzles I would tend to think would be responsible of greater losses, both frictional and eddies, and lower turbine output as a consequence, but at first sight the pressure drop will depend mostly on steam pressure at the inlet valve, and condenser pressure. I believe the pressure is commanded, so as to say, by factors external to the turbine, and the turbine always trying to do its best. I compare with an electric motor, working with a voltage not depending on the motor but rather on the line to which the motor is connected to. I hope not to be misleading.

Claudio Molanes

Post a Reply...
Viewed 3640 times

Sunday, December 18, 2016   By: Jim Watts [764] 5 Stars
If you use the search menu above and use wheel Chamber in the search term you will find a number of discussions and references to this issue.

Depending on your turbine configuration for the last governor valve, the wheelcase pressure can rise for fouling increase and also rise for fouling decrease if final valve closes in reducing bypassing the first stage.

Nozzle wear will increase the pressure at valves wide open but not if throttling.

Lower vacuum increases the steam flow for the same load so will increase pressure.

Fouling will increase pressure but will also increase exhaust steam temperature above condenser saturation temperature.

Post a Reply...
Viewed 3656 times

Wednesday, December 21, 2016   By: Bonga [2008] 0 Stars
Many Thanks Jim and Claudio for time and thoughts through my requests, very much appreciated.

I was worried about focusing more on fouling and leaving other important aspects that may also affect the wheel chamber pressure. Part of my thoughts were that if the nozzles are worned out theyll not reduced the pressure prior to wheel chamber and the7refore if the vacuum remains the same, the wheel chamber pressure will increase. Similarly to poor vacuum, it will increase the back pressure on the turbine and therefore increase the wheel chamber pressure. Like what Claude has said, wheel chamber pressure is the resultant of what is happening on its either sides.

Am I also correct to say if nozzles are worn out, the steam velocity into the reaction blades will decrease and therefore to maintain the same power ouput from the turbine, more steam would be required and this can also increase the wheel chamber pressure at a fixed condenser load/duty.


Post a Reply...
Viewed 3448 times

Wednesday, December 21, 2016   By: Jim Watts [764] 5 Stars
You are absolutely correct.
For normal conditions downstream of the wheelcase, the wheelcase pressure is directly proportional to steam flow. I have seen it used as a steam flow indicator on a 45 mw condensing unit.

Post a Reply...
Viewed 3392 times

Published on steamforum.com


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


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