Apex Series

70-1200 HP

PREMIUM 3 Pass Firetube Boiler
Industry Leading Wetback Design

Boilersmith AP3 Apex Series
Boilersmith AP3 Apex Series
View printable literature – Apex Series AP3


  • WETBACK for low maintenance, long life and maximum efficiency
  • Liberal dimensions; durable, proven three-pass firetube arrangement
  • Flexible firing rate and output
  • Undesirable, throw-away, non-repairable construction is avoided (as seen on some watertube and exotic boiler designs)
  • “Off the shelf” components resulting in lower parts cost
  • Minimal Service costs
  • Heavy-duty, first-class materials
  • Renowned for a long life, up to 30 years or more
  • Equipped with premium, packaged FORCED DRAFT burners; factory test-fired
  • Extra handholes are provided, in a superior location, in the front tube sheet below the furnace
  • Thoughtfully engineered; enhanced by our extensive design experience
  • Excellent overall plant efficiency (83% plus combustion efficiency on natural gas, 85% plus on No. 2 oil)
  • Skillfully crafted to high standards
  • Ample steam space/release surface
  • Doors open without removal of burner components or fuel and power lines
  • Large 5/8″ BOLTS are used on all doors; fewer are required; opening/closing is faster; easily damaged studs are avoided
  • Heavy door gaskets are intended for repeated use and are easily replaced
  • Outstanding inspection accessibility

Standard Steam Trim

  • Safety valve(s)
  • Waterglass set
  • Pressure gauge
  • Gauge cock
  • Trycocks
  • Pressure control – high limit (manual reset)
  • Pressure control – operating
  • Pressure control – high fire or proportional firing (full modulation)
  • McDonnell & Miller 157S low water cutoff and pump control
  • Water column blowdown valve
  • Manual reset, probe type auxiliary low water cutoff control
  • Stainless steel feed water check valve
  • Feed water shutoff valve
  • Ball type, quick opening, bottom blowoff valve (Optional quick opening valve types are available)
  • Slow opening Y-pattern globe, bottom blowoff valve
  • Surface blowdown skimmer pipe, ball valve and throttling valve
  • Drain valve
  • Stack thermometer

Standard Hot Water trim

  • Relief valve(s)
  • Pressure guage with gauge cock
  • Water temperature indicator
  • Manual reset, probe type low water cutoff
  • Operating temperature control
  • Manual rest high limit temperature control
  • High fire temperature control or proportional firing rate (modulationg) control
  • Drain valve
  • Stack thermometer

Premium Performance

The furnaces of APEX Series boilers are of large diameter and ample length. This, along with the full water-cooled rear chamber, ensures that the furnace absorbs much more heat, maximizing efficiency and minimizing pollutants, while allowing tubesheets to have a cooler, longer life.

Options and Alternatives

We specialize in customizing your boiler. The APEX can be equipped to suit a wide variety of installations and specifications. We will help direct you to the most cost-effective models and features.