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Swygart25604  
#1 Posted : 19 June 2018 09:46:47(UTC)
Rank: Forum user
Swygart25604

I have just arrived in a role where we have a CHP Plant newly installed on site, which contains a diathermic oil system (heat convection), leading to a hear exchanger. 

For air pressure systems, there is obviously PSSR 2000, but what about these sorts of oil systems? Do they need a written scheme of examination in similar vein, and to what regs would the inspection be? The system operates at 6 bar, and is rated at 10 bar max.

Unbelievably, its slipped through the project management company overseeing the project, and the supplier has yet to come up with the goods. I would like to establish the correct position as a starting point.

HSSnail  
#2 Posted : 19 June 2018 11:38:05(UTC)
Rank: Super forum user
HSSnail

PSSR is not just about air its also about fluids at a pressure 0.5 bar above atmospheric (from memory), but as for the examination i think there is a volume requirement as well. Should be in the ACOP. And why is the Secruity Image drip is IOSH getting at me?
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Swygart25604 on 19/06/2018(UTC)
Swygart25604  
#3 Posted : 19 June 2018 12:08:59(UTC)
Rank: Forum user
Swygart25604

Hi Brian,

So the answer is......L122,  Page 9, Figure 1.....is there a relevant fluid in the system and a pressure vessel that has a pressure x volume product of 250 bar litres or more, as to the duties you have under PSSR 2000.

Thanks!!

Granlund40055  
#4 Posted : 19 June 2018 12:20:06(UTC)
Rank: Forum user
Granlund40055

Is the diathermic oil a relevant fluid as defined in Reg 2 (pg 11 of the ACoP).  Such oils have very low vapour pressures.  What is the max operating temp and therefore the vapour pressure ?

ie "relevant fluid" means—

(a) steam;

(b) any fluid or mixture of fluids which is at a pressure greater than 0.5 bar above atmospheric pressure, and which fluid or mixture of fluids is—

(i) a gas, or

(ii) a liquid which would have a vapour pressure greater than 0.5 bar above atmospheric pressure when in equilibrium with its vapour at either the actual temperature of the liquid or 17.5 degrees Celsius; or

of course PUWER still requires a maintenance regime.

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Swygart25604 on 19/06/2018(UTC)
Swygart25604  
#5 Posted : 19 June 2018 12:40:52(UTC)
Rank: Forum user
Swygart25604

Hi,

Good point.............which I will check and find out.

Thanks!!

Swygart25604  
#6 Posted : 19 June 2018 13:14:02(UTC)
Rank: Forum user
Swygart25604

The plot thickens slightly.......

The system doesn't have vessel as such, in which the state of a fluid is changed. The system goes into heat exchangers and returns through the same loop. It would be operating at a maximum of 300C.

So is Figure 1 of L122 to be read that its only a pressure vessel that should contain steam or to have a pressure x volume product >250 bar litres (presumably)? As opposed to a "system" having that pressure x volume product? Strictly speaking, it reads just "pressure vessel" to me and so should be pretty clear? Or am I missing something?

If this is the case, then Regs 8-10 don't apply, but Reg 15 will, which is taken care of in the system design.

Comments gratefully received.

HSSnail  
#7 Posted : 19 June 2018 14:27:45(UTC)
Rank: Super forum user
HSSnail

A very quick internet search would suggest the vapour presure of the oil is 0.45Bar at 300C so as Granlund40055said it may not even be a relevant fluid - but i would check that figur carfuly.

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Swygart25604 on 19/06/2018(UTC)
Swygart25604  
#8 Posted : 19 June 2018 14:43:13(UTC)
Rank: Forum user
Swygart25604

Hi All,

Thank you very much for the advice and thoughts; I'll get the TDS for the oil in question and we'll work it out to confirm.

bunster  
#9 Posted : 22 June 2018 11:13:55(UTC)
Rank: Forum user
bunster

If you have the TDS just check the flashpoint of the oil, if this is less than the operating temperature of the system this may also come under DSEAR regs 

Ian Bell2  
#10 Posted : 22 June 2018 12:07:20(UTC)
Rank: Super forum user
Ian Bell2

The oil will only come under DSEAR if classified as 'dangerous' i.e. flammable/highly flammable etc.

Under CLP that means a flashpoint of 60deg C or less

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Swygart25604 on 25/06/2018(UTC)
bunster  
#11 Posted : 22 June 2018 12:59:58(UTC)
Rank: Forum user
bunster

Originally Posted by: Ian Bell2 Go to Quoted Post

The oil will only come under DSEAR if classified as 'dangerous' i.e. flammable/highly flammable etc.

Under CLP that means a flashpoint of 60deg C or less

Yes I agree however the reason I mention this is because I had an incident with a thermal oil system where a small leak occured in the system and because it was under pressure a vapour was formed which fortunately set off the fire alarm system and alerted us to the leak.

While investigating the cause of the leak, an examination of the oil found that it had degraded over time significantly and had reduced the flashpoint from 240 deg C to below 60. We had to change all the oil in the system and as part of the maintenance procedure have a sample of the oil tested annually. 

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Swygart25604 on 25/06/2018(UTC)
Swygart25604  
#12 Posted : 25 June 2018 07:29:34(UTC)
Rank: Forum user
Swygart25604

Hi guys,

The site is subject to DSEAR due to the nature of what is produced, but this area is new and is awaiting a repeat assessment to confirm the new equipment, so thanks for the heads up! I will take both points about the oil on board.

Thanks to all who have contributed!

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