Q: What marking(s) should be on a steam generating power boiler operating in excess of 100 psi?
A: Regardless of size, in 48 of the 50 states, an ASME mark with an “S” designator and registration with the National Board is required.
Q: Is there a size exemption for power boilers smaller than 6 inches in diameter?
A: NO! There is no size exemption in the ASME B&PVC for steam generating power boilers operating in excess of 15 psi.
Q: Some units have the ASME mark with a “U” designator. Is this an acceptable substitution for the ASME mark and the “S” designator?
A: NO! The “U” designator complies with a completely different Section of the ASME B&PVC and is not appropriate for steam generating power boilers operating in excess of 15 psi.
Q: Are steam generating power boilers that have been designed to conform to the EC Pressure Equipment Directive (PED) (97/23/EC) acceptable to use in the United States?
A: NO! All steam generating power boilers operating at pressures in excess of 15 psig fall under the jurisdiction of the ASME.
Q: If steam generating equipment has an ASME mark with an “E” designator, does it matter what ASME mark and designator are on the steam generating power boiler?
A: YES! The same principles stated above still apply. The power boiler must have the ASME mark with the “S” designator and registration with the National Board.
Q: If the material of a steam generating power boiler is stainless steel, is it acceptable to use either tap water or well water?
A: NO! Only deionized (DI) water may be used with a stainless steel steam generating power boiler.