Boiler Blog | Nationwide Boiler Inc.

Improper water treatment is the leading cause of tube damage and poor performance in a boiler system. In this month’s edition of Boiler Basics 101, we will discuss the consequences of introducing your boiler to hard water and the importance of utilizing a water softener.

If water is not treated properly before entering the boiler, scale will begin to form due to a chemical imbalance within the tubes. Scale is defined as concentrated minerals being precipitated when the water is evaporating in a boiler. The precipitated minerals consist of a mixture of calcium, magnesium, iron, aluminum, and silica, and are often referred to as “hard minerals”. Scale is detrimental in a boiler system because it acts as an insulator and prevents proper heat transfer. This can lead to decreased boiler efficiency, costly downtime, and even premature boiler failure. Eventually, scale build-up will cause boiler tubes to overheat and rupture.

To help prevent scale and deposit formation, make-up water should be circulated through a water softener before it is fed to the boiler. A water softener is an ion exchanger designed to remove positively charged ions from hard minerals (like magnesium, calcium, and iron) and replace them with negatively charged ions. The resin beads that are inside the resin tank are negatively charged by brine, which contains salt and potassium. As the water goes through the resin tank, the positively charged ions are chemically attracted to the negatively charged resin beads. The hard minerals then stick to the resin as the water runs through the tank, thus turning the water into “soft water”. This process frees the water from these minerals before entering the boiler and decreases the risk of tube scaling and irreversible damage.

Water softening is one of the main ways to increase boiler longevity and maintain boiler performance. Nationwide Boiler’s fleet of mobile boiler rooms, steam plants, and feedwater system trailers include duplex water softening systems to ensure optimum boiler performance. We also have skid-mounted and trailer-enclosed, stand-alone water softeners available for rent or for purchase. It’s important to know that when Nationwide Boiler delivers a rental unit, it is the customer’s responsibility to maintain and supervise the water treatment and chemistry of the water entering their rental boiler.

All boilers are subject to damage if proper water treatment procedures are not followed. This is an important consideration both during operation and when the boiler is idle. To avoid damage and costly repairs, monitor water chemistry routinely and ensure that you are supplying your boiler with soft water at all times.

The price of fuel is constantly fluctuating and with it comes creative ways to be more economical. Finding methods to be more energy efficient is never a waste of time. In the boiler room, efficiency improvements can be found by many sources, however, a common option for energy savings includes the use of an economizer. What is an economizer? The economizer is a fabricated assembly of finned tubing that captures waste heat extracted from the boiler’s stack flue gases; the exhaust that leaves the boiler stack (or “flue”).

It’s all about the principle of Heat Transfer. While low temperature water, or feedwater, enters a boiler system, high temperature flue gas exits. An economizer captures heat from the flue gas that would typically go to waste, and utilizes it to preheat the feedwater. By doing this, an economizer is able to increase thermal efficiency by decreasing the energy required to heat the water to steam. This will typically result in a reduction of 1% in fuel cost per 10 degree rise in feedwater temperature. Overall, an economizer can be a major cost savings for boiler owners and will easily provide a quick return on investment.

The economizers’ simple technology and static parts provide longevity and low maintenance, and they are available in multiple designs and configurations. Conventional economizers are cylindrical or rectangular and come in a range of sizes for both firetube and watertube boilers. Rectangular designs are more commonly used for larger industrial watertube boilers, and can be configured for vertical or horizontal gas flows, finned or bare tube design, and other additional options if needed. A condensing economizer can improve waste heat recovery even further by cooling the flue gas below its dew point, reclaiming both sensible heat from the flue gas and latent heat by condensing the flue gas water vapor.

BOILER EFFICIENCY COMPARISON
	Combustion Efficiency at 4% Excess Oxygen	Stack Gas Temperature
Boiler	78% to 83%	350F to 355F
Boiler with Standard Economizer	84% to 86%	250F to 300F
Boiler with Condensing Economizer	92% to 95%	80F to 150F

When determining whether an economizer is ideal for your boiler equipment, the location of the economizer into stack is important. To ensure the most thermal recovery during the process, you need to make sure the economizer is installed as close to the furnace breach as possible. This will help avoid thermal loss and cooling.

At Nationwide Boiler, we offer our EconoStak economizer as an optional addition (or a standard addition in some cases) on our fleet of watertube rental boilers. The EconoStak consists of the economizer as well as all of the associated piping and structural supports required for very efficient and safe operation. In addition, we are a West Coast representative for E-Tech Heat Recovery Systems, a leading provider of economizers for new, replacement, and retrofit applications.

Contact Nationwide Boiler today to see if an economizer is the right option for you, and be sure to check out our previous Boiler Basics 101 blogs. We review various topics each month, so stay tuned for the next edition!

With California having the most stringent emissions requirements in the country, it is important to be well versed on any and all rules and regulations when buying a new boiler or renting a temporary boiler. This is our final installment of the 3-part series on air permit compliance for boilers in California (be sure to check out part 1 and part 2 if you haven’t already).

Nationwide Boiler maintains a fleet of rental units that are sub-9 ppm NOx and pre-permitted for use in the SCAQMD. We take care of the bulk of the permit work saving our customers an exponential amount of time (no waiting for the application to be approved), and we pay for any processing fees. This allows for quick installation and start-up of a temporary boiler, which is extremely valuable in an emergency outage. The only requirement of our customer is the source testing of the equipment, if the source test is due. Most of these pre-permitted boilers require source testing on an annual basis, and the source test must be done at a job site within the county’s jurisdiction.

The SJVAPCD does not allow the pre-permitting of rental boilers, but they do have a program called the Temporary Replacement Emissions Unit (TREU) which can be utilized when a rental is needed  in a pinch. This program contains an application shield provision which allows renters to install a temporary boiler in place of an existing permitted boiler that is down for repairs without having to get a new permit for the rental boiler. In order to qualify for the TREU Program, the rental boiler being installed must have a heat input equal to or less than the unit it is replacing. Plus, it must not have the potential to produce more emissions than the current permit allows. There is a time limitation to this program; the temporary boiler can be on-site for a maximum of 180 days within a 12-month period.

If you are outside of the two territories listed above, don’t fret! Nationwide Boiler can assist with the permitting process as needed. In addition, utilizing a pre-permitted boiler in a location other than the SCAQMD does have its advantages and can help expedite the permitting process.

With our headquarters being located in California, it is important to us that we are up-to-date with emissions regulations throughout the state. And with other areas of the country starting to experience a similar push for emissions reductions, we have the expertise and experience to help. Nationwide Boiler is proud to take the lead in helping customers everywhere understand and comply with current and future air regulation standards.

Routine boiler maintenance is imperative not only for safety, but also to sustain efficiency and reliability of your system. Being proactive rather than reactive is likely to increase the longevity of your boiler as well as help prevent incidents that can result in injuries, damage, or worse. Incorporating routine maintenance into your facilities day-to-day operations will prove its worth with a great deal of short- and long-term benefits.

There are certain maintenance tasks that should be performed daily, and others that should be performed periodically. Below we have provided a list of best practices to follow when putting together your routine boiler maintenance plan.

On a daily basis, you should track and keep a log of the following items:

• Boiler pressure and temperature
• Stack temperature, to determine operational efficiency (a well-tuned boiler should have a stack temperature range of 50 – 100 degrees above the steam or water temperature)
• Gas pressure to the regulator, as well as downstream from it
• Water quality and pH levels, to ensure you are meeting the recommended levels

Blowdown of the boiler (bottom blow) and water column should also be performed on a daily basis. In addition, you should observe boiler and auxiliary equipment daily to ensure proper operation and that there is no damage, leaks, or unusual behavior. 

On a weekly to monthly basis, it’s important to conduct additional visual inspections and observe the operation of certain components for areas that may need to be addressed. This includes:

• Gauge glass
• Fuel supply valves
• Operating and modulating controls, water level controls
• Flame scanner & burner flame pattern
• High- and low-pressure switches, combustion air proving switch
• Indicating lights and alarms

When it comes to the burner, you should inspect the valves, pilot tube, and diffuser thoroughly for any signs of wear that might call for a repair. Also, be sure to observe the entirety of the boiler system for potential hot spots (an indicator of deteriorated refractory) and again, be sure to keep an eye out for any leaks of fuel, water, or flue gas.

Lastly, there are certain items that should be performed on a semi-annual to annual basis. Many of the tasks below can be checked off during the annual inspection, when the boiler is taken offline:

• Open access doors and inspect the fireside of the boiler
• Inspect boiler and tubes for evidence of corrosion; clean tubes and tube sheets thoroughly
• Examine the refractory for large cracks (greater than 1/8”) and patch as necessary
• Conduct safety tests on the gas valves
• Review all electrical connections for tightness, signs of wiring wear
• Check pump alignment on all base-mount pumps

This is also a good time to fully inspect the auxiliaries that provide fuel, air, water, and chemicals to the boiler. In addition, combustion should be reset periodically with the use of a combustion analyzer, for accurate readings of NOx, CO, and O2.

While the guidelines above provide a good baseline of tasks to perform when it comes to routine maintenance, be sure to consider the boiler manufacturer’s recommendations as well.