View Full Version : NH3 Valve Exercising Program

10-06-2015, 05:47 AM
I am looking for information on valve exercising programs. We currently do not have a program in place and I think it is time we do. What I am questioning is, how frequent, the type of lubricant to apply while exercising and what to apply after the exercising is complete? I have looked around and WD40 and petroleum jelly are what I see talked about the most. Maybe these are the best products to use but it seems like a home remedy to me. Also any other suggestions would be helpful. Thanks in advance for your help.

10-06-2015, 07:19 AM
It is great to see someone approaching preventive maintenance as this appears to be a dying art in all industry these days.
A study found that in 2002 the best companies were only carrying out 31% of cost effective maintenance. In the UK it has been observed that preventive maintenance levels have fallen below 10%.

Valve easing is the easiest task to implement with great returns for effort.

All valve manufacturers recommend that valves are operated on a 3 monthly schedule from fully open to fully closed.
A further recommendation is that critical isolation valves are removed and inspected every 2 years (never happens)

Greasing and lubrication do not really apply as valve shaft seal prevent ingress / egress what you are trying to do though with a lubrication regime is prevent spalling of exposed shafts etc. any form of corrosion inhibitor will work.
For high humidity and environmental exposed areas I have found that Denso tape is unbeatable (grease impregnated tape)

Gears require a high pressure grease and WD40 will wash away, molybdenum greases and sprays are excellent in most areas and dry PTFE sprays work well with synthetic lined bearings/seals etc.

Good old petroleum jelly is cheap and effective in preventing corrosion on most exposed surfaces.

The loss of good maintenance is a sad day for engineers as arriving on a fully maintained site to witness poorly implemented maintenance regimes just reflects badly on the engineers attending, To readers - Ask yourself when last you fully operated a valve and greased exposed surfaces? Then consider holding down bolts etc. etc.

A wise older man I work with ran a large refrigerated port in the Arab countries and employed a person solely to grease and paint valves etc. on a continuous basis. If equipment looks good people treat it with respect, have faith in the equipment, are under the opinion equipment is maintained, which further encourages good maintenance and customer investment.

10-06-2015, 11:33 AM
Hookster, it is really informative feed back. I know one dyestuff and dyes intermediates industry in India, where there are more than 30 to 40 refrigeration Ammonia based systems, mainly flake ice plants, brine chilling and water chilling plant. That industry is having around 125 reciprocating compressors. One of my friend is maintaining all these plants. On reading your feed back I discussed with him and learned that he takes shut down of all these plants in sequence for preventive maintenance. Each plant undergoes preventive routine once a year. The Ammonia is removed from the system and system is pressure tested, all the valves are operated as explained by you and some of them are replaced if stuck. The thickness of receiver and shell and tube condenser shell is measured by ultrasonic meters. Compressors are overhauled in-house. His spares cost is unbelievably low - USD 8000 to 10000 for these 125 compressors annually. The oil removed from these plants is disposed off as per pollution control board norms. He has maintained a record of oil drained from each drain point and how much oil is topped up or replaced for these compressors for almost last 20 years. Really Amazing.

10-06-2015, 05:27 PM
Yes Sandy
That is excellent maintenance and it is good to hear it being applied in practice. Good maintenance saves time and money.
Unfortunately most maintenance over here is lip service and profit margin. You just have to look through the photos on this forum to realise it!

Fixing a breakdown is all kudos and satisfying, while preventing that failure in the long run is the real talent.

10-06-2015, 11:59 PM
Hi Hookster
There is an old saying "An ounce of prevention is worth a ton of cure", it's a pity a lot more companies don't do preventative maintenance instead of breakdown maintenance. Sadly most maintenance is based on cost these days.

[Fixing a breakdown is all kudos and satisfying, while preventing that failure in the long run is the real talent.]
This is very true.

11-06-2015, 06:03 AM
I agree with all the sentiments as per previous posters, but after repeatedly quoting maintenance programs for plants I am getting screwed by the bean counters.