Identifying and Reducing Steam System Costs
By way of background, I am an industry professional with over 23 years’ experience in the construction, maintenance, and trouble-shooting of steam piping systems. Over the course of my career, I’ve studied the various factors that contribute to steam system costs as I’ve worked across a number of industries, including petro-chemical, pharmaceuticals, steel, paper, universities, hospitals, and power generation. I’ve enjoyed sharing and gaining knowledge and experiences with co-workers along the way, as well as teaching Apprentices and Journeymen in the piping trades.
A Step in the Right Direction
In recent history, facilities have started to take on the steam system by monitoring one of its biggest offenders – steam traps. This is a good place to start since it turns out that insights about your traps also provide you with an understanding of the steam system itself, helping to identify some of the other costs I discuss below. In the past, personnel manually inspected traps every 12 months or more in what’s called a “steam trap audit.” Although it seems hard to believe, some facilities still think that annual spot checks suffice.
Today, Everactive offers a high-tech product that can wirelessly and battery-lessly audit the steam trap every minute, every day, every week, all year long, year after year – alerting you to steam trap failures as they happen, so that you don’t have to wait until next year’s audit. If you wanted to achieve Everactive’s level of real-time insight with the outdated manual inspection process, it would cost you a laughable $10,512,000 per year … per trap. It seems time to turn to new technology that can help you tackle all the costs associated with your steam system.
Understanding Your Costs
This post will outline the various factors that impact your total steam system costs, including, but not limited to, those due to steam trap failure (for a more in-depth look at steam trap failure, see Everactive’s white paper How to Reduce the Hidden Costs and Dangers Lurking Throughout Your Steam System). Most steam system costs will vary considerably depending on many different factors of your operation, but identifying these root issues is the first step in improving the efficiency of your entire steam system.
1. Steam Generation
a) Water Costs – The United States averages $3.50 / kGal for water from Utilities. The amount of make-up water used per day is dependent upon the number of steam system leaks, whether all condensate is collected and returned to the boiler, and boiler blow-down rates, which, on average, are about 6-10% of the make-up water flow rates. Monitoring your make-up water usage with a meter will give the cost-accurate translation into dollars spent.
b) Fuel Costs – This cost is by far the easiest cost to track within your steam system as natural gas & fuel oil meters accurately track your usage. While coal consumption is not as straight forward to track, you still can track amount used over time and easily determine a dollar amount.
c) Boiler Efficiency – Industrial boilers, on average, operate at 80-85% efficiency rates. In most cases, it is safe to assume the unloaded cost of steam, at minimum, is $5.00 / 1,000 lbs. of steam. The fully loaded cost of steam, a more honest representation of steam cost, will often be much higher.
d) Chemical Treatment – This is a necessity for any system to ensure a long life free from scale, rust, erosion, pitted boiler tubes, and corrosion. Based on your annual order history, you can easily understand your material costs. However, if the correct amounts are not used, or the correct type of treatment is not used, your boiler and system may fail sooner and that later realized cost become very significant as you are forced to replace the boiler and piping. Also, testing the boiler water is a cost!
e) Boiler Equipment Maintenance – Annual shutdowns for required boiler inspections are costly, even for smart facilities that plan equipment replacement during these shutdowns.
f) Boiler Blow Down – This is a purposeful process conducted on a regular basis to remove impurities that build up in the boiler and steam system from the boiler. But, the problem is that in most cases, this ends up wasting heated boiler water and chemicals, contributing to more costs!
g) Boiler Operator – An obvious need and requirement, yet another cost that adds into your total steam system cost.
2. Steam Distribution
a) Main / Branch Sizing – Improperly sized mains & branches can make your boiler work harder just to keep up with supply demands. Another cost.
b) Pressure Reducing Stations / Control Valves – Similarly, improper sizing and valve failures lead to increased costs.
c) Insulation Thickness – Throughout the whole system, an adequate thickness of insulation is required to keep thermal loss at bay. Recent increases in the required thickness for insulation on piping means that your facility probably does not have the proper amount and most likely you are losing $ based on losing heat all along the steam system. Insulating all the existing exposed piping in the system is the best place to start. Putting a dollar amount on your existing losses due to inadequate insulation can be challenging to accurately capture, but surely something you want to fix.
d) Piping Additions / Changes / Maintenance – If a facility has a 50-year-old steam system, yet every ten years there have been additions to that system with new piping feeding new applications, it will most likely result in additional costs. This is due to the likelihood that old pipe mains are not sized correctly for these expansions and load. Having to repairing old failing portions of your system and maintaining equipment fed by steam represents a significant cost–in labor, material, and time.
e) Steam Leaks – I personally cannot remember ever seeing a site or facility with zero steam leaks across the entirety of the system. Cost!
3. Process Usage
a) Venting Air – It is vital to remove air from the steam system. Air inside of a steam pipe acts as an internal insulator and reduces the efficiency of the steam system. Steam traps and air vents are an important part of many applications served by steam; installing these correctly and ensuring that they work properly will reduce costs.
b) Proper Steam Traps for Process – Without the proper trap type and/or with poor piping designs at the served process, you will be subject to inefficiencies. Moreover, steam coils and heat exchangers are subject to “binding” and “stalling.” To counter this, in multiple customer cases, we see a drain valve purposefully installed before the trap and after the heat exchanger, which is left in the open position to ensure that the heat exchanger is always empty of condensate. This drained condensate is not returned to the boiler and demonstrates a huge waste of energy and, you guessed it, another addition to the total cost of steam.
4. Condensation Collection
a) Steam Traps – Steam traps do exactly what their name implies, if working properly and when installed on a properly engineered and sized system. They trap or stop steam from continuing into the condensate system or being released into atmosphere. Properly functioning traps cycle to release built up amounts of condensate and safely keep steam on the other side. If a trap fails into a leaking-by or blowthrough state this can represent one of the biggest total steam system costs. For example, a single ¾” thermostatic trap blowing through off a 100psi steam system can easily cost a facility tens of thousands of dollars per year in wasted energy. If you consider a facility-wide failure rate of 20% (per the Department of Energy), that adds up fast across hundred or thousands of traps. How many traps do you have at your facility? Do you know how much they cost you each year?
b) Condensate Pumps – You guessed it again, these fail all the time and they add undue costs to your steam system.
What Should You Do?
We just discussed the total costs to factor when trying to determine your true cost of steam, yet we haven’t even touched on the cost if failures happen within the system and cause process shut downs. How about the true cost of emissions from your boiler? It seems like a countless amount of things to count, and that is why I believe too many facilities do not bother to even try to tackle their steam system issues, because to them it can be overwhelming and they do not know where to start and they trick themselves into just being happy with the way things have been.
But, with a little effort, savings can start adding up fast and you will begin to know what you don’t know now about your steam system.