Bill Truesdell, freelance writer

Technical Writing

Here is a selection of technical writing samples:

Plant Engineering: Trapping water in compressed air systems

Air traps remove water and suspended contaminants while minimizing the loss of compressed air.

Plant engineers who pay more attention to compressed air systems usually pay less to compress air. Damage due to freeze-ups, dirt fouling, and corroded system components is reduced.

Making dry compressed air a plant priority could yield enough savings to shut down a second compressor or delay the investment in a new one. The first step toward any savings is understanding the importance of moisture removal from a compressed air system.

Moisture in a compressed air system reduces system efficiency in several ways. Moisture can wash away lubricating oils in air tools, instruments and equipment. Water in components may freeze if the ambient temperature drops below freezing. Slugs of condensate, rammed through the system at high velocity, can create water hammer and differential shock.

High-speed slugs impact and gradually erode piping elbows, valves and motor vanes. Pitting of these surfaces gives salt ions and acids a place to accumulate and cause further damage through chemical action. The weakened surfaces are then vulnerable to stress corrosion from mechanical vibration and water hammer.

How Rex Materials Group’s TCS Can Help You Win the Battle Against High Operating Costs.

Win the barrel heating/cooling battle and reduce your operating costs while saving up to 70% on energy costs in the process.

There is new hope for extruders and injection-molding operations struggling to hold their own against increasing operating costs and soaring energy costs. Controlling barrel temperatures has always been a struggle against the high energy costs of heating, slow response time, uneven temperature control and high maintenance costs—especially of water-cooled equipment.

But now producers have a new ally in this dilemma with Rex Materials Group’s unique and patented barrel heating and cooling technology. Barrel heaters – which must first heat themselves before conducting heat into the barrels – traditionally control barrel temperatures.

Rex Materials Group’s patented Thermal Control Solution (TCS) barrel heating and cooling system consists of heating segments with a radiant heating element embedded in high-temperature ceramic fiber insulation. The heater segments are wired together in series, wrapped around the barrel and secured with high-temperature Velcro.

During the heating cycle, TCS uses the radiant heaters embedded in the high-temperature ceramic insulation to direct heat into the barrel while minimizing heat loss. Since there is virtually no thermal mass to the heater, there is no corresponding lag time or wasted energy. Couple this with the use of radiant heat transfer, and the barrel gets to the set point temperature much more quickly than traditional conductive-type heaters.

If cooling is required to control barrel temperature, usually forced ambient air or water is used to achieve this cooling. However, ambient air systems are slow, and water systems have high maintenance requirements which mean excessive downtime and wasted energy.

By providing an air gap between the radiant heaters and the barrel, TCS solves the cooling challenge, too. The gap is designed to expose about 75% of the barrel surface area which allows high-velocity air provided by a high-suction blower to immediately begin cooling the barrel.

This new take on barrel cooling requires virtually no maintenance. What’s more, it captures the waste heat for re-use such as space heating. Plants can also exhaust the heat inside in the winter or outside in the summer to keep the plant cooler and reduce air conditioning costs.

Rex Materials Group says the TCS is easy to install, offers tighter temperature control and provides a safer work environment because its insulation makes it safe for workers to touch the outside of the heaters, even at full operating temperature.

Since introducing the TCS in 2005, Rex Materials Group has revolutionized barrel heating/cooling technologies—and turned a lot of assumptions about annual energy savings inside out.

Excerpt from an Armstrong International Bulletin on Electronic Steam Humidifiers

Methods of steam distribution

The Series EHU-600 is designed to provide maximum flexibility for steam distribution. Steam can be distributed through an air-handling system (normally an existing air duct) or directly into the area being humidified with the Armstrong EHF fan packages.

Duct-type distribution. Where an existing air duct system is available, steam can be introduced into the duct through steam dispersion tube(s).

The selection of the steam dispersion tube(s) should meet the duct requirements as noted in Chart 6-1. As an example, if the air duct in which you are installing the humidifier has a width between 17 and 22 inches, you should use steam dispersion tube Model D-1.5. If the steam dispersion tube would be located below the humidifier, install a drip leg with water seal.

Area distribution method. The Armstrong EHF fan packages provide humidity distribution where an air-handling duct system is not available. The attractive EHF-2 unit may be installed directly on top of the Model EHU-600 Humidifier. The EHF-2 and 3 units may be hung on a wall and used in conjunction with any appropriate Series EHU-600 Humidifier.

The maximum humidity dispersion capacity of each EHF-2 area fan package is 30 lbs/hr. It is incorporates a blower rated at 115 v.-1.3 amp. CFM rating is 280 CFM @ 1,380 RPM.

Excerpt from the Installation Manual for Outback Steel-Framed Gable Buildings

Proper Use of This Manual

Before beginning construction of the building, read the following notifications and notices to understand how this manual is to be used.

This manual is a reference source, with information on how to construct a typical OutBack building. It is not a set of specific instructions for your building. There are no specific measurements or comprehensive component lists in this manual. For specific measurements and components for your building, please see the engineering plans.

Please be aware of the following:

  • This manual is to be used for reference only, and the information contained in it is not specific to your building.
  • For information specific to your building, please consult the engineering plans.
  • This manual must be used in conjunction with the engineering plans.
  • All measurements are to be taken from the accompanying plans and specifications.
  • The engineer’s plans override any information in this manual.
  • This is not a work safety manual, so it is of utmost importance to follow all safety recommendations of OSHA (Occupational Safety and Health Administration).


  • Please adhere to all local building department requirements.
  • Do not work on the building in damp conditions and do not walk on roof sheeting in damp or frosty conditions.
  • If you are employing a tradesman to erect your building for you, check with the governing authority to see if he needs to be licensed. Also verify that all insurances for both the tradesman and his employees are current.

This manual is to be read in conjunction with:

1. Engineering plans – The engineering plans contain the foundation plan, all elevations and all connection details specific to your building. The engineering plans contain all pertinent information for the construction of your building.

2. Bill of materials – The bill of materials is a list of all ordered components of the building. Please consult the bill of materials as soon as possible after delivery to ensure all necessary components have been received and to ensure the timely replacement of missing parts.

Description of Engineering Plans

The engineering plans consist of the following sections:

1. Foundation plan – Typically located on sheet 1 of the engineering plans and labeled as 1/1, this displays the foundation of the building and many components in relation to the foundation. Items indicated on the plan include doors and windows (which can be referenced from the above Door and Window Schedule), sidewall/endwall columns and x-bracing.

2. Sidewall exterior elevations – Typically located on sheet 1, with the front elevation labeled as 2/1 and the back elevation labeled as 3/1, these display the view of the sidewalls as shown from the outside of the building. Items indicated on the elevations include wall girts, roof purlins, x-bracing and vertical bracing.

3. Endwall interior elevations – Typically located on sheet 1, with the left interior elevation labeled as view 5/1 and the right interior elevation labeled as 4/1, these display the view of the endwalls as shown from the interior of the building. Items indicated on the elevations include wall girts, roof purlins, columns, rafters, endwall columns, x-bracing and flybracing.

4. Mezzanine plan (if applicable) – Because this doesn’t exist on every building, its location on the Engineering plans is variable from building to building. This plan shows the layout of the mezzanine. Items indicated on the plan are mezzanine joists, mezzanine girders and columns.

5. Connection details – These details are typically shown on sheet 2. They consist of all the connections necessary for the construction of the building and are referenced from the plans and elevations on sheet 1.

6. Slab detail – Typically located on sheet 2, this shows the construction of the building foundation slab.

7. Member and material schedule – Typically located on sheet 2, this lists materials and members used in the construction of the building. It is referenced throughout the Engineering Plans, as well as this manual.

8. General structural notes – These are general engineering notes, listing various requirements for the construction of the building.