Johnston Boilers

Johnston Boiler Company pioneered the first water backed boiler over 100 years ago, and the first packaged water backed boiler over 50 years ago. Johnston features a complete packaged boiler that needs just the essential utility and discharge hook-ups before supplying your steam or hot water needs. The complete package is thoroughly factory fire tested at all applicable loads and fuels prior to painting and shipment.

Depending on design and operating pressure, efficiencies reach 90% - the highest in the industry without turbulators or an economizer. Minimum use of refractory and the full water back design reduces maintenance while at the same time enhances pressure vessel longevity.

From front to back, top to bottom, every Johnston “J21” or “509” series boiler comes with an unprecedented – industry leading 15 year warranty covering the tube sheets, furnace, rear combustion chamber, and flue doors – materials and labor.

4-Pass Design

For many years, there were two choices – a 4 pass dry backed boiler or a 3 pass water backed boiler. This was a hard decision for many users. A 4 pass would have a higher efficiency, but higher maintenance costs associated with frequent refractory repair. While the 3 pass water backed required less maintenance, a decrease in efficiency could be expected.

In 1978, that all changed when Johnston introduced the first packaged 4 pass water backed boiler. Now, a customer could have the best of both worlds – water backed reliability with 4 pass design efficiency.

Every Johnston 4 pass maximizes effective heat transfer using a full five square feet of heating surface per BHP while at the same time eliminating tube sheet stresses and costly maintenance repairs that are common with dry backed designs.

3 Pass Design

When Johnston introduced the first 3 pass water backed firetube boiler to the market back in 1934, it changed the boiler industry forever.

Today, the Johnston 3 pass boiler is still a strong and dominate force in the boiler industry with its high steam and water storage areas, high efficiencies, rugged construction, and its ability to keep up with wide load demands.

The Johnston 3 pass also offers something the competition doesn’t – watertube capacity with firetube efficiency. Up to 2500 BHP (86,250 PPH) is available, while maintaining the Johnston water backed quality the industry has grown to respect.

Like the 4 pass, the 3 pass incorporates a design that maximizes heat transfer while minimizing the use of refractory – no expensive door repairs. Both the 3 and 4 pass models offer the same 15 year limited pressure vessel and 15 year front and rear flue door warranty.

Lower maintenance costs, fuel savings, and long term durability are all major factors in choosing the right boiler for your project. We encourage you to compare our boilers to the competition. In the end, there is no equal to the original – Johnston.

XID Scotch Marine Boiler

The XID Boiler is designed specifically for industrial process steam installation requiring extremely dry steam, high peak demand and rapily changing loads. The XID Boiler has several important design advantages:

Distance from normal water line at steam nozzle is up to 2 times that of older design, completive boilers.
Steam volume is 2 or more times that of older design, completive boilers.
Generous furnace volume provides greater primary heat transfer surface and improved burner operation.
Waterback design eliminates costly refectory repair and thermal stress on the rear tube sheet.
15 year warranty provided for furnace, tube sheets, combustion chamber and fluid doors.