CAST IRON AT SUB ZERO TEMPERATURES

[gorkus]

would be cast iron PUMP(gg-20)able to stand lower temperatures?
The pump is going to be installed outside and the temperature could be up to minus 30 deg.C.

 

[SNORGY]

What is it pumping? If it is pumping water, it won't be operating under pressure at -30 C, for example (not very well, anyway). If the fluid is benign, then a cracked pump might not be all that big a concern.

Still, for cast iron, if only to protect one's investment, I would winterize it - or else go to DI or something.

Regards,

SNORGY.

 

[gorkus]

the fluid pumped is car oil

 

[JoeySoap]

I have had a cast iron pump pulled apart as the piping cooled (and contracted) after the pump stopped. It was warmer than -30 Celsius too.

 

[seymours2571]

It depends. Gray cast iron would be a no go at those low temperatures. Ductile iron may work, but it would depend on the stress the housing is subjected to and the grade of ductile iron.

Stephen Seymour, PE
Seymour Engineering & Consulting Group

http://www.seymourecg.com

 

[gorkus]

The working pressure is 2 bar
the flow is 500 l/h

and its grey cast iron , grade gg-20.

the pump will be cover with some type of insulation.

 

[JoeySoap]

I suspect that you are at risk of pulling the pump apart from the brief details given here. As I posted above, I've seen it happen on a Cast Iron pump that was piped up with Carbon Steel piping that cracked the pump casing when it cooled down one winters night. If I recall correctly, the night time temperature only went down to about -10 Celcius or so in that case. But the pump still cracked all the same. The cracked pump dumped solvent all over the floor and into the plant drains. The local environment agency were not amused.

 

[MartinSr00]

Grey cast iron is very brittle -- even under temperate conditions.

For me, the rule has always been for cast iron no more than 100 psi or so pressure, ambient service, no thermal shocks.

It's like putting a glass and putting it on the stove. Heat it slowly and you might be ok. Anything goes wrong, it cracks.

 

[bingopin]

My "rule of thumb" is no cast iron in any hydrocarbon service regardless of temperature. At -30C, I would not use ductile iron. Go with steel.

 

[GaTechTheron]

Automotive oil is not a hydrocarbon, and it is fine with Iron. However, I would never use Cast Iron or Ductile Iron in a service this cool. Go with Steel.

 

[BigInch]

Better you secondary contain that too.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[hbw]

Brittle failure at low temperature is a serious consideration. Brittle failure occurs suddenly and without warning. Pressure containing materials for low temperature service must be ductile. Grey cast iron is brittle at any temperature and should not be used at low temperature. You should use a carbon steel or stainless steel pump that rated for use at the service temperature per ASME Section 8 and Section 2. Contact a pump vendor for a recommendation.

Low temperature piping will impose thermal expansion / contraction loads (forces)on the pump nozzles.

 

[Clvet]

-30 C is about -22 F. Ductile if I recall is rated to -20 F, after which it begins to lose it's "ductility". I don't have a tremendous amount of experience with cast, but I've seen ductile used in services going down to -90 F. I would never recommend it but I've seen it done and at that low of a temperature. There you'll definitely have brittleness issues but at -22F, ductile should be fine.

 

[reel]

We have almost 20 DI pumps installed outside (-30C/-40C in winter) and pumping RUG, diesel, etc. Never had any problems during normal operations. Problems could arise when you start pumping a hot media without insulation. I would not use a cast iron pump.