4-Pass Boiler
The 4-pass design was first built in 1978 so that customers could have water back design reliability with the four pass design efficiency.
Features
- Efficiencies up to 90%
- Low Maintenance Costs
- 15 Year Warranties
Overview
Johnston's 4-pass design was first built in 1978 so that customers could have water back design reliability with the four pass design efficiency. Every Johnston 4-pass maximizes effective heat transfer using a full five square feet of heating surface per BHP. Also, the rear tube sheet has only one inside and one outside surface temperature, which reduces stress and keeps maintenance to a minimum. As the combustion chamber is part of the pressure vessel, internal water circulation is improved and overall boiler efficiency is enhanced.
Each boiler is fully factory fire tested over the complete operating range. The boilers are built in accordance with the latest ASME code requirements, National Electric Code and other required local, state and insurance requirements. Dependent on the design and operating conditions, efficiencies can reach up to 90%. Here at Johnston, we strive to supply the right products for your special applications.
DOCUMENTS & DOWNLOADS
| 3 and 4 Pass Boiler Brochure 3 and 4 Pass Boiler Brochure.pdf | |
 | Johnston Boiler Guide Specifications Johnston Boiler Guide Specifications.exe |
