Model 4
1,500 – 6,000 MBTU
Rev. 03-08
Section B2-2
ILLUSTRATIONS
Figure B2-1. Model 4 Dimension Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-9
Figure B2-2. Model 4 Standard Pilot and Main Gas Trains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-2
Figure B2-3. Boiler room air supply - “Engineered Design” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-19
Figure B2-4. Typical gas header piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-26
TABLES
Table B2-1. Model 4 Boiler Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-5
Table B2-2. Model 4 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-10
Table B2-3. Model 4 Steam Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-11
Table B2-4. Recommended Steam Nozzle Size (to maintain 4000 to 5000 fpm nozzle velocity) . . . B2-11
Table B2-5. Min. req. NATURAL GAS pressure STANDARD UL, FM, & XL GAP gas trains . . . . . . . B2-13
Table B2-6. Min. req. NATURAL GAS pressure OVERSIZED UL, FM, & XL GAP gas trains . . . . . . . B2-13
Table B2-7. Min. req. PROPANE GAS pressure STANDARD UL, FM, & XL GAP gas trains . . . . . . . B2-14
Table B2-8. Min. req. PROPANE GAS pressure OVERSIZED UL, FM, & XL GAP gas trains . . . . . . . B2-14
Table B2-9. Safety valve outlet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-15
Table B2-10. Predicted efficiency, 10 psig operating (includes radiation and convection losses) . . . B2-15
Table B2-11. Model 4 emission data - Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-16
Table B2-12. Model 4 emission data - No. 2 Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-16
Table B2-13. Feedwater makeup rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-17
Table B2-14. Water quality parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-17
Table B2-15. Model 4 fuel, combustion air, and flue gas flow rates . . . . . . . . . . . . . . . . . . . . . . . B2-19
Table B2-16. Gas line capacity - Schedule 40 metallic pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-22
Table B2-17. Gas line capacity - Schedule 40 metallic pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-22
Table B2-18. Gas line capacity - Schedule 40 metallic pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-23
Table B2-19. Gas line capacity - Schedule 40 metallic pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-24
Table B2-20. Gas line capacity - Schedule 40 metallic pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . B2-25
This section contains information on the Model 4 Commercial Watertube Boiler product line for low and high
pressure steam applications. Sizes range from 1.5 to 6 MMBtu/hr. The Model 4 Boiler is an excellent choice
where high outputs are needed but space limitations exist. The model number designation is 1500 through
6000, representing MBtu/hr input (1,500,000 to 6,000,000 Btu/hr).
Fuel series designation is as follows:
• Series 100: No. 2 oil firing.
• Series 700: Natural gas firing.
• Series 200: No. 2 oil/natural gas firing.
Design pressure designation is stated as 15 psig, 150 psig, and 250 psig for steam. For example, an M4P-
700-2500-150ST boiler designates a gas-fired, 2,500,000 Btu/hr, 150 psig, steam boiler.
