Rental Boiler Guidelines & Considerations
by Micahel Medina
April 1, 2010
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| Figure 1. Whether a boiler is shipped
by air, trailer, rail, or sea, it is important that you plan in
advance for its arrival. (70,000 lb/hr trailer-mounted boiler being
loaded on the Antonov AN124-100 aircraft.) |
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There are over 160,000 industrial and
commercial boilers in the United States producing steam and hot water
for industries including food, paper, chemical, refining, power, and
metals.
Whether it is for an unplanned or
planned maintenance outage, increased capacity requirements, or
because of an unforeseen project delay or act of nature, the demand
for rental boilers will exist. When the need arises, there are many
aspects of renting a boiler that users must consider and address. By
understanding the rental process and following the guidelines below,
it is possible that the result will be both cost-effective and
technically successful.
MOBILITY AND LOCATION
Upfront planning is the most important
stage when renting boiler equipment. The first requirement is
determining the total capacity and operating characteristics of the
boiler system. Multiple boilers can often be arranged in parallel to
increase plant capacity to any desired level, although this may
involve renting one or multiple mobile steam plants or
trailer-mounted boilers.
When possible,
mobile equipment is preferable to skid-mounted equipment and is less
costly, due to fast delivery and no special foundation or footing
requirements needed to support the unit. In addition, when compared
to a skid-mounted boiler, a trailer-mounted boiler (with a capacity
up to 120,000 lb/hr) is the most economical to rent, since the need
for a new foundation, crane handling, and special rigging can be
avoided.
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| Figure 2. Two 70,000 lb/hr
trailer-mounted boilers and one 140,000 lb/hr mobile feedwater van. |
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Careful evaluation of a location that
can handle the requirements of boiler equipment is also important.
The location must be easily accessible for the delivery and setting
of heavy machinery and must be able to support the bearing load of a
trailer-mounted truck and the load of a boiler. The site must also
have ready access to the building or process steam main and allow for
easy connection to fuel, water, and electrical power supplies. The
connection sizes must be verified to meet the needs of the rental
equipment, and early determination of proper sizing will save
valuable time when the equipment arrives.
SUPPLIER CONSIDERATIONS
Once maximum potential steam
requirements are determined and an ideal location for the equipment
has been selected, it is time to evaluate a supplier. Though not
always feasible, the best way to evaluate a rental company is to
visit its facility. Observing work in progress at the company’s
facility can provide valuable insight into the quality of the
equipment and service the company is accustomed to providing.
However, if you are unable to conduct a site visit, then asking the
right questions will quickly help you decide which company you feel
most comfortable to rely on to meet your unique needs and
requirements.
An item to consider during the
evaluation process includes knowing if the company is a full-time,
dedicated rental company with the experience, equipment, and
capabilities you require. Be cautious with firms that claim to be
full-time and offer below market-level pricing. Sometimes these firms
can offer a better price, but equipment age, reliability, startup,
support, code compliance, and conformance to emissions regulations
are a few areas that may require extra attention.
Next,
pay special consideration to where the company’s equipment is
located, in addition to the location of technical representatives and
start-up technicians. Most established rental companies have trained
representatives in all major industrial areas who are trained and
familiar with the rental company’s equipment and procedures. In
addition, you should always ask if the rental company has multiple
storage locations, which aids in minimizing transportation costs and
travel time.
When it comes to evaluating a
supplier’s proposal, there are a number of issues that need to be
addressed to make certain that what you want and need are what you
are going to be charged for. The proposal should include normal
factors, such as a clearly defined rental rate, payment terms,
change-of-scope clauses, liability coverage, transportation costs,
and a warranty statement. A well-written proposal should also address
the anticipated term on the rental unit, freight costs, and time and
travel charges for technicians and should specify appropriate
responsibility for installation and removal costs. It should also be
clear that any additional costs, such as for repairs resulting from
normal use, should be the responsibility of the rental company.
Moreover, repairs that result from poor maintenance or improper
operation from the rental company will be billed back to the company.
In addition to a concise proposal, reputable
rental companies will also be able to provide a complete set of
drawings and equipment specifications in considerable detail.
Detailed equipment specifications include items such as the total
capacity and operating characteristics of the boiler, water treatment
needs and requirements, emissions requirements, weather protection,
performance testing, and ASME code requirements.
PREPARE FIRST, THEN MAINTAIN
Once a rental company is selected, the
rental agreement signed, and the delivery and start-up schedule is
determined, the user must be certain that the site is ready for
delivery and well-trained boiler operators have been selected to
safely operate the equipment. The next step is to arrange for any
necessary operating permits required from regulatory agencies. This
includes any special permits that may be required in those areas
where emission limits are strictly controlled. For locations that
must comply with stringent NOx regulations, be sure to inquire about
low NOx technology options such as selective catalytic reduction
systems that can be easily installed and shipped with the boiler to
make certain environmental compliance is achieved.
To
ensure continuous, safe, and trouble-free performance, there are a
number of regular checks and maintenance tasks which must be
performed during normal operation of the equipment. It is important
that a log sheet be kept on site for the recording of every routine
check and maintenance items completed.
Daily
checks include an examination of all safety devices, followed by an
inspection of the low-water cutoff during every shift. The entire
system should also be checked for leaks, including the fuel supply
system. Any irregularities must be corrected immediately. It is also
important to check the flame pattern of the burner to make sure the
combustion devices are working efficiently.
To
maintain continuous proper boiler performance, feedwater treatment
and correct blowdown techniques must be performed. Makeup and boiler
water quality should be checked at every shift and boiler water
treatment chemicals must be used. Failure to maintain proper water
chemistry is a major cause of damage to rental boilers and the single
biggest rehabilitation expense. Make sure the rental company provides
sample coolers on their equipment to facilitate the water chemistry.
Also, get your water treatment company on board right away to include
the rental boiler in their normal services.
CLEANUP AND RETURN
There are certain steps to ensure the
safe return of a unit to the rental company’s facility. It is the
responsibility of the user to have plant or local boiler shop
personnel disconnect equipment after use, which includes draining and
flushing all boiler lines with clean water to help minimize any
chance of corrosion. This also applies to valves, gauges, controls,
and piping which are susceptible to freezing when exposed to wintry
conditions during transit. Next, the stack,
non-return valves, and safety valves are to be removed and securely
stored in their proper place for shipment. Lastly, a complete check
of the condition of the boiler and the boiler tubes for build-up
should also be noted. When the final inspection is complete, all
items should be properly documented, recorded, and sent to the rental
company once the equipment is shipped back to the rental
company. Even if all the guidelines above are
considered, it is still possible for things to go wrong. Most often,
this relates to reasons including inadequate planning and budget
allotment, non-engineering installation, lack of qualified operators,
poor water treatment, and lack of proper maintenance. As long as you
plan in advance, budget accordingly, verify connection sizes and
permitting issues, properly train operators, frequently monitor the
feedwater quality, and take responsibility in maintaining the
equipment once it is installed, you can be confident that the risks
associated with renting equipment will be minimized and that your
project will be a success. It may never be
quite as easy to rent a boiler as it is to rent that convertible on
your vacation, but with a little advanced planning and by exercising
a little caution when evaluating the supplier, the equipment, and the
proposal, you can avoid most potential problems that you might not
otherwise consider. Nationwide Boiler’s
Emergency Preparedness Plan is a useful tool to aid in planning for
the installation of a temporary steam plant before the need actually
arises. Download your free copy today at www.nationwideboiler.com.
TB
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