View Full Version : Save money / close call

16-07-2006, 05:50 PM
Away to save money when you are a well known company in frozen food. It starts with not covering the refrigeration engineer who is off sick. So you cover his time off with an electician who can start the plant and freezers. This was O.K. until this week when the oil loading and unloading control valve block for a WRV 255 Howden compressor whent wrong. So he switched off the electrical control side and shut off the oil feed line from the oil separator. He then started to remove the 4 cap head screws and found it was still under pressure some how!. This left an out line of him on the wall 6mts. away before he could stop the oil.
As the compressor had stoped with 4 Bar Ammonia pressure in the head and oil separator and 4 pipes connected to the valve he could not under stand where the oil came from. ( I did let him know as I then had to come in and change the valve.) He had not even shut the suction or delivery valves on the compressor.

US Iceman
16-07-2006, 07:13 PM
HI Arthur,

That situation is why it is important to have written procedures and to have personnel who are trained on the system in those procedures.

Hopefully, no one was injured.

Other than their knickers. :D

16-07-2006, 07:33 PM
Hi Iceman, We have written procedures and PTW system in place but no control, They seem think that anyone who has seen the written procedure can do the job. They get upset when you walk away when not happy with the safety side of the job.

US Iceman
17-07-2006, 05:46 PM
Hi Arthur,

What is a PTW system? That's different terminology than what I'm used to.

If your company is large enough don't they have a Health & Safety person who administrates the program?

There have been some cases here worse than the one you described. One person was killed, the other was rendered legally blind.

Same type of thing. Two mechanics were sent to work on a scraped surface heat exchanger. Written procedures were in place I believe, but the mechanics were just general sorts. Not refrigeration guys.

They opened up the heat exchanger with the ammonia still in it!

Very, very sad.

Having procedures also means only qualified personnel should be doing the work AND that they are trained on the procedures.

I don't blame you for walking off if you consider the request dangerous.

Perhaps you should let the person requesting the work, to do it themselves by following the procedures.:rolleyes: (i'm not being serious with this comment, but I think you understand what I mean:D )

I am continually surprised by the managerial people who think they understand everything, and won't listen to someone who has more knowledge on the subject.

17-07-2006, 07:03 PM
Iceman, PTW = Permit To Work

US Iceman
17-07-2006, 08:23 PM
Got it, thanks Brian.

Does this require a specific training time for each operating procedure before the permit is issued?

Or, are the permits issued after just reading the procedure?

Sir Josiah Sodd
17-07-2006, 09:16 PM
Permits are an official recognition of hazardous work.
It's a form of words that recognises hazardous procedures and set out rules of conduct.

Similarly you obtain a 'hot work' permit if you are welding / brazing or using a bare flame. The company will have a set fire protection procedure that you have to comply with.

18-07-2006, 07:06 PM
Hi Iceman,
All they seem to care about now is the envioronment and paper work. The out come of this one was to dig out the procedure for pumping down a low side compressor connectet to a common low pressure suction with other compressors, so you do not need to use a vac. pump as you have -30" vac in the common suction, and get every one to sign it off. This is OK but the unit where it happend was a stand alone plant with only one low side unit.
All the engineers working on the refrigeration plant should have been trained and hould a Safe Handling of Ammonia card.
About 3 years ago they put out a procedure for working on the refrigeration plant and said that we had to sign it off, It said that we had to start the fans in the roof if we have a leak. OK but the Ammonia leak system shuts off all the elec. power to the factory. So I did not sign it off.

US Iceman
18-07-2006, 07:17 PM
HI Arthur,

...but the Ammonia leak system shuts off all the elec. power to the factory.

That is one of the inconsistencies of ammonia systems and interpretations of safety regulations.

The fans need to be kept running to vent the ammonia (which decrease the likelihood of higher concentrations developing into a real problem).

My preference is to shut off all electric, except the fans. However you still need adequate emergency lighting.

From a safety standpoint consider this: You need to have the lights on to see what you are doing right. If you shut the electricity off, the lights go out.:o

If you use incandescent lamps and one gets broken, there is your ignition source.

There are a lot of "little" problems like this that should be carefuuly reviewed.

18-07-2006, 07:49 PM
Hi Iceman, This is why I will not put my Name down to this safe system of work, After all I only live with and work on the plant. The one who had the leak system in is only seen when you want new parts for it. Have asked how we pull off the pressure from the system with no power. We need a new bit for it now.
A new 187HP elec. motor that whent Bang to day and had to remove, only 9 more to go in this heat but keep all the doors shut and brick up all the windows some one may hear them running and call in about it.

US Iceman
18-07-2006, 08:16 PM
Hey Arthur,

...keep all the doors shut and brick up all the windows some one may hear them running and call in about it.

Are you in an area close to people then?

Oh boy, if that's the case you are faced with some issues.

I think the sound issue could be solved by some sound attenuation on the ventilating air inlets or fan systems.

But as you know, everything costs money!

The money spent on replacing motors will pay for some corrective work, but sometimes the managers don't see it like that.:(

PS. I don't blame you for not signing the paper. I wouldn't either.:D