PVI Designs and Delivers Customized Water Heaters for the U.S. Military

In August 2013, PVI Industries delivered the last of several hundred, highly customized water heaters designed exclusively for U.S. Army Force Provider and successfully concluded a 5-year contract.

PVI initially contacted the Army in November 2002 upon discovering the military was highly dissatisfied with the performance and longevity of the existing field-deployed water heater. Finding a replacement was among the highest priorities of the Force Provider group whose primary purpose is to support deployed troops with necessities including shelters, showers, laundries and field kitchens – all containerized for rapid deployment.

Designed by the military in the 1960s, the existing heater was functional but understandably far beneath the technology available in today’s commercial water heater market. It was plagued by poor combustion and limited service life, with many heaters developing unrepairable leaks after only a few months of operation. The cost of continually replacing the heaters became unacceptable.

PVI’s involvement with the Army began with the discovery of a request for quotation for the existing water heater on a government procurement website. Purely out of curiosity, drawings were acquired and these indicated that the general size and performance requirements were a good fit with PVI’s manufacturing and custom design capabilities. The existing heater was a hybrid fire tube and shell-in-shell heat exchanger design. The exchanger and tank were fabricated from carbon steel with roughly 40 gallons of water storage and the heater utilized an unusual and relatively crude fuel oil combustion system rated at an estimated 500,000 Btu/h. PVI’s interest was not to build the existing water heater but, if possible, to introduce the military to an entirely different and vastly improved heater design.

The challenge now turned to locating the individuals in the military responsible for designing, specifying and managing the acquisition of the field-deployed water heaters. After several phone calls to different military installations, PVI was eventually directed to Force Provider in Natick, Massachusetts. Concurrent research revealed that the military was unsatisfied with the existing heater and was urgently looking for a replacement.

PVI contacted U.S. Army Force Provider saying only “we heard you are looking for a replacement for the field deployed water heater, and we think we have a solution.” Force Provider engineers agreed to supply the general specifications for the replacement heater. PVI began a custom design and proof of concept process and soon returned a proposal based upon a significantly size-reduced adaptation of the TURBOPOWER oil fired water heater– a design that had been commercially available for twenty years. The Btu input, size and the weight of the heater were essential requirements and the PVI proposal meet all three. Force Provider agreed to test a PVI prototype in spring 2003.

Engineers at Force Provider were impressed by the hot water output and combustion quality of the first prototype and they requested delivery of two additional second-generation prototypes in fall 2003. That began a four year product development relationship where PVI’s engineering supervisor worked directly with the Force Provider engineers on the design of several additional prototypes incorporating modifications and improvements suggested by both parties. Every year, these prototypes were sent to various branches of the military for field use and evaluation; including forward base camps in combat zones. By 2008, the Army began purchasing the water heaters in small quantities for inclusion into containerized field systems for immediate delivery overseas. The final prototype (version VIII) was sent to the military’s Aberdeen proving grounds for environmental, vibration and drop testing.

Field evaluation of the prototypes was so positive that a performance specification was prepared to include all of the capabilities of the PVI water heater, now named the AWH 400 by the U.S. Army.
The water heater was required to meet the following requirements:

  • Provide 9 gallons per minute at a 90°F temperature rise
  • Prove the ability to operate under extreme heat and extreme cold
  • Prove the ability to operate after exposure to highly corrosive, salt spray environment
  • Prove the ability to operate in torrential rainstorm conditions
  • Prove the ability to operate immediately after extreme vibration testing
  • Prove the ability to operate immediately after drop testing from a height of three feet on all four corners of the heater
  • Prove the ability to operate on three primary fuels; #2 diesel, military JP8 and military JPA
  • Combust fuel with a smoke measure of less than 2
  • Weigh less than 500 pounds and include fork lift accessibility as well as carrying handles on all sides of the heater
  • Provide tight temperature control around the operating set point while using a semi-instantaneous, low-water-volume design

The PVI heater incorporated a modern packaged oil burner, a passivated stainless steel storage tank, copper alloy tank connections and 100% accessibility to both the tank and heat exchanger by virtue of a heat exchanger connected to the tank by a bolted flange. The PVI heater, although downsized from the commercial version, still provided a thermal efficiency of 81% which was a substantial improvement over the existing heater. Because downtime had to be minimized, the PVI heater included replacement parts stored in the upper portion of a NEMA 4X control enclosure.

In June 2008, PVI was awarded the contract as sole provider of the AWH 400 heaters to the U.S. Army and several first article test units were manufactured. One was shipped to Natick for review and approval, and an additional verification trial at Aberdeen. Four water heaters were subjected to RAM testing (reliability, accessibility and maintainability) at PVI where they were exposed to the elements in a specially constructed outdoor test facility. RAM testing required more than a thousand hours of run time using military JP8 fuel with strict limits on heater downtime and maintenance. Failure of the RAM test would jeopardize the contract. In the RAM test and at the Aberdeen proving grounds, the U.S. Army’s new AWH 400 passed with flying colors.

In March of 2009, PVI began delivery of the heaters at the rate or 25 per month for each delivery order received. In every case, the heaters were delivered ahead of schedule and on budget. The heaters are now being used by the U.S. Army, U.S. Air Force and U.S. Marine Corp in bases across the U.S. and around the world. The field response to the new AWH 400 heater has been entirely positive with the heater exhibiting exceptional reliability after many thousands of hours of operation in severe environments and without a single heater experiencing a corrosion failure of the tank or heat exchanger. The success of the AWH 400 is a shining example of close cooperation between U.S. Army engineers with critical and unique requirements and a commercial water heater manufacturer with many years’ of experience, applicable product designs and the ability to custom design and manufacture.

PVI is proud to have worked with U.S. Army Force Provider to develop the AWH 400 water heater for the well deserving men and women in all branches of the U.S. military serving around the world.