Products 2018-02-09T14:21:37-08:00

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NPJ is ready to deliver services that include everything from consulting to plant design and installation.

We’re committed to finding cost-effective and creative solutions for your steam needs.

Our complete list of services includes:

  • Turnkey Projects
  • System Design and Engineering
  • Project Management

Installation control panels, cabling, and instrumentation and make start-up adjustments to the combustion of burner

NPJ have formed team of experienced engineers who maintain contacts and relations with local engineering and construction companies that by decade have already established themselves as successful contractors to all industrial plants and facilities.

The D-type water tube boilers represent one of the most popular boiler configurations and this design is offered by a lot of industrial boiler manufacturers around the world. This type of boiler is often specified by consulting engineers although it is not symmetrical and well balanced as an A-type or an O-type boiler but it is a well-designed which has proven itself as being reliable.

  • Capacities from 4.5 TPH to 180 TPH
  • Design pressure from 4 barg to 103 barg
  • Temperatures up to 480 oC
  • Right hand and left hand models are available
  • Water wall design built with gas tight membrane or tangent tubes
  • Operate with natural gas, #2 & #6 fuel oil and alternative fuels
  • Meets or exceeds NOx Emission Standards while providing high turndown ratio

The A-type water tube boilers represent a symmetrical, well balanced Boiler with a large furnace volume, designed with a centered steam drum and two lower mud drums. Radiant and convective type super heaters can be added at the rear end of the A-type units and

provide superhe

ated steam at a constant temperature over all the firing range. For very large capacities, high pressures and temperatures, it is often the choice of the consulting engineers and of the end users.

An O-type water tube boiler represents an alternate way of designing water tube boilers. It is symmetrical, well balanced and very compact compared to D-type boilers and A-type boilers. Capacities for O-type package units can go as high as 115 TPH with pressures up to 103 barg and temperatures up to 565 oC. It is appropriate where space is limited. It can be field erected if required by site conditions or for size larger than 115 TPH. It can fire any fuel but may be less appropriate to fire no.6 oil than an A-type or D-type boiler. Solid fuels like wood wastes cannot be fired in the O-type furnace and if used have to be burned in separate combustion chamber. Furnace sizes are smaller than a D-type or an A-type and will result in higher heat release rates influencing NOx levels. They are also used as heat recovery steam generators.

The Aquatube Boiler is one of the Watertube Boilers that used  where hot water or steam is required for heating or for the processes like dry cleaners, apartment, building etc., in institutional parts like schools, university campus, hospitals and industrial parts like oil & gas plant, food industries, textiles, pulp & paper, wood processing etc….

The Aquatube is also ideal for boiler replacement projects. The boiler may be provided pre-assembled ex-works and ready for start-up or delivered in modules and assembled onsite using conventional boilermaking techniques.


The Aquatube’s large furnace design, combined with the small amount of refractory used in the boiler, insures minimal per-cubic-foot  heat loss and low NOx emissions.

Standard Equipment

  • High pressure or temperature control (manual reset)
  • Operating pressure or temperature control
  • Low water level cut-off electrode
  • Thermometer or pressure gauge
  • Safety valves
  • Optional combustion control system and boiler accessories available to meet the most stringent specifications and applications.
  • Control panel assembled at the boiler or burner
  • Fully modulating or high-fire/low-fire burner
  • Flame supervision system
  • Main fuel and light-up gauges
  • Convenient operator control devices and indicator lights


  • The Aquatube boiler is a water tube boiler consisting of multiple runs and circuits/elements balanced by a staggered tube arrangement and longitudinal gas passes.
  • The Aquatube boiler’s symmetrical tube arrangement, along with the staggered tube design of balanced gas and water flow, insures optimal heat transfer under turbulent flow.
  • Symmetrical tube arrangement means that tube replacement requires only half the width of the boiler: a plus for multiple boiler facilities.
  • Boiler casing is extremely well insulated. Boiler tubes are insulated with 2-inch ceramic wool high-temperature resistant casing supported by ¼-inch inner liner impervious to combustible gas. The inner casing is insulated on the outside with another layer of 2-inch commercial insulation covered by outer corrugated steel sheets. Radiation loss is low and outer casing temperatures remain below generally accepted limits.
  • Efficiency of up to 85% is possible without adding recovery equipment.


  • Low- and high-pressure steam
  • Low- and high-temperature water
  • Glycol water solution
  • Thermal liquid up to 600°F (315°C)
  • Tangential tube furnace wall
  • Water-cooled rear membrane wall (optional water-cooled front membrane wall)

It is obvious that efficient garbage disposal and treatment result in positive effects on the environment.
However, from all the existing technologies, only waste-to-energy does not generate negative impacts on the long-term.

The garbage is completely and immediately burned, without any damage to the environment and generate electricity. The combustion residues are inert due to the high temperature involved. Consequently, no negative impacts are neutralizing the positive effects on public health and on the environment.

  • Dual Fuel Burners & Retrofits
  • Recovery Boilers & HRSG
  • Pressure Vessels and Condensate Tanks
  • Fired Heaters
  • Heat Exchangers
  • Utilities Equipment
  • Deaerators,  Flash Tanks and Blowdown Tanks
  • Tubes for Boilers