Minimum Pressure rating for boiler feedwater, blowoff valve and flange
Minimum Pressure rating for boiler feedwater, blowoff valve and flange
(OP)
Hello,
I have question about ASME B31.1 Power Piping.
In case of feedwater and blowoff, when designing the piping, the presssure shall exceed MAWP by either 25% or 225 psi whichever less.
Acording to ASME B31.1 "Poer Piping" 122.1.7
It says " The minimum pressure and temperature rating for all valves and fittings in steam, feed water, blowoff, and miscellaneous piping shall be equal to the pressure and temperature specified for the connected piping on the side that has higher pressure, ..."
When designing the feedwater, blowoff valve and connecting flange, does "the pressure and temperature specified" in 122.1.7(ASME B31.1) mean MAWP or "25% or 225 psi exceeded MAWP"?
Thank you!!
I have question about ASME B31.1 Power Piping.
In case of feedwater and blowoff, when designing the piping, the presssure shall exceed MAWP by either 25% or 225 psi whichever less.
Acording to ASME B31.1 "Poer Piping" 122.1.7
It says " The minimum pressure and temperature rating for all valves and fittings in steam, feed water, blowoff, and miscellaneous piping shall be equal to the pressure and temperature specified for the connected piping on the side that has higher pressure, ..."
When designing the feedwater, blowoff valve and connecting flange, does "the pressure and temperature specified" in 122.1.7(ASME B31.1) mean MAWP or "25% or 225 psi exceeded MAWP"?
Thank you!!





RE: Minimum Pressure rating for boiler feedwater, blowoff valve and flange
For superheater, economizer, blowdown ,etc the drain valve and piping design pressure would be MAWP plus gravity head. MAWP is the steam drum design pressure, and the steam drum is usually higher than the drains, unless they built the boiler upside down:)