Reference Manual

10B −10
impregnation vessel to raise the temperature of
chips and liquor going to the digester.
D Typical process conditions:
— Fluid: Black liquor
— T = 345_F
— P = 250 psig – 275 psig
— dP = 38 psi – 75 psi
D Typical valve selection:
— NPS 6 to NPS 8 valve with an alloy 6
scraping seat due to concerns over the
precipitation of calcium carbonate causing
plating or scaling buildup. A SST V300 valve
with an alloy 6 HD seal and alloy 6 bearings
should be used in this application.
Valve: TV-60A-C Bottom circulation
temperature
These valves control steam to the bottom
circulation heaters which, in turn, control the
temperature of liquor leaving the heaters for the
bottom zone of the impregnation vessel.
D Typical process conditions:
— Fluid: Steam
— T = 400 – 525_F
— P = 165 psig
— dP = 60 psi
— Q = 10000 – 40000 lbs/hr
D Typical valve selection:
— These are throttling valves, typically NPS
6, for which Kamyr has specified V300
valves with stainless steel bodies and
stainless steel trim. Nitronic 50 shafts, PEEK
bearings, and HD metal seals are also called
for.
Valve: PV-10 Digester pressure relief
This valve is used in emergency situations to
relieve elevated digester pressure by releasing
black liquor from the top screens to the No. 2 flash
tank. This valve requires tight shutoff and
fail-closed spring return actuation.
D Typical process conditions:
— Fluid: Black liquor
— T = 350_F
— P = 180 psig
— dP = 180 psi maximum
— Q = 2600 gpm
D Typical valve selection:
— Kamyr has specified full bore ball valves
for this application. However, a CV500 (NPS
3 to NPS 6) in stainless steel with alloy 6 trim
is an excellent valve for this application.
Valve: PV-11 Digester pressure control
This is a critical valve in the digester process. This
valve is used to maintain pressure in the digester
and to distribute fresh cool water to the pulp. This
prevents the overheating of the pulp, which would
result in the degradation of the pulp fibers. This
valve is typically interlocked with PV-10 to prevent
over-pressurization of the process.
D Typical process conditions:
— Fluid: Washer filtrate
— T = 180_F
— P = 250 psig
— dP = 55 psi
D Typical valve selection:
— Kamyr has specified a Vee-Ball V300
valve, NPS 4 to NPS 6 size, for this
application. The valve should have a
stainless steel body and ball, Nitronic 50
shaft, PEEK bearings, and an HD metal seal.
A piston actuator is typically used.
Valve: HV-54 Top circulation pressure
control
This valve is used primarily during start-up to
supply cooking liquor to pressurize the top
circulation lines prior to pumping.
D Typical process conditions:
— T = 170_F
— P = 320 psig
— dP = 45 psid
— Q = 400 gpm
D Typical valve selection:
— The V300 valve is an appropriate
alternate valve for this tag. This valve is
typically in the NPS 3 size range.
Valve: HV-52 Top circulation isolation
valve
This valve serves to isolate the high pressure
feeder line from the impregnation vessel. It is
typically installed on the main chip/liquor feed-line.
D Typical process conditions:
— T = 240_F
— P = 250 psig