Hi there
The duty you describe is a fairly agressive one, and one which is prone to
misoperation. The blowdown tank will be fitted with water sprays to condense the
flash steam and cool the blowdown to a level suitable for drainage. Trouble can
start if, for example, there is insufficient spray water and blowdown is called
for to control a drum water level excursion. Then, the blowdown tank drain can
be subjected to the flash steam temperature instead of the cooled blowdown
temperature.
I have seen CPVC used in an application similar to the one you describe, and it
was/is badly buckled but still operating (serving a battery of 10 bar saturated
steam boilers). Not sure of the cause but the boiler operators said it was due
to occasional hot discharges. Unless the flash temperature is lower than the
allowable temp for CPVC and adequate expansion provision is made, I would be
looking for a material with higher temperature rating and appropriate corrosion
resistance. Alternatively it may be cheaper to arrange a backup blowdown tank
spray water supply. In any case I would probably not bury the line - a pipe duct
would be more appropriate as the duty is severe and periodic repairs and
maintenance are likely to be required.
Cheers
Steve
To: PipingDesign@yahoogroups.comFrom: ashok_yargol2000@yahoo.comDate: Mon, 7 Jan 2008 06:20:14 +0000Subject: [PipingDesign] regarding CPVC pipes
in a powerplant we have blowndown tank normally consists of condensate from boiler and from that blowndown tank i want to use CPVC pipe , this pipe runs underground and gets connected to another tank.now my question is can we use CPVC pipe other than any CS pipe
[Non-text portions of this message have been removed] Received on Mon Jan 07 04:42:00 2008
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