MOV Long Life greases tested by EPRI for high temperature MOV's and for bearings
in Lube Notes for December 2006. Both did very well in comparison to the
alternatives, especially when all the characteristics were considered.
Note Number 1, High Temperature Grease Evaluation: "The MOV LL result at the
stem nut temperature of 85°C (185°F) warrants consideration in future testing.
Not only does it appear that it will retain oil better, but it also has better
oxidation stability and consistency retention (remaining a grade 2) than the
other lubricants evaluated."
Note Number 3, Comparison of Roller Bearing Greases: "We believe that MOV LL
will prove to be superior in antirust based on other, more rigorous tests. This
feature is important in areas of high humidity near an ocean. Given that a
bearing failure occurred due to a weld seize, there is a comfort in choosing
MOV LL that has a significantly higher weld point and load-carrying ability."
Click here for
See the movement of MOV Long Life Grease in a Limitorque SMB actuator
To order MOV Long Life, MOV Extra or VSG
Forsythe at 800 305-2806
For US sales of MOV Long Life and MOV Extra other options call
at 770 426-607 or 800 536-6070, Fax 770 426-6191.
Actuation at 800-829-8145 and Fax 770-926-1637.
Technology at 800 448-1795 x104 and Fax 713 932-6874.
MOV Long Life Grease
MOV LONG LIFE – Limitorque SMB Gearbox Grease - Service Lives and Cost Savings
Value User's Group (Note: these require being a MUG member)
paper 02G-JO1, Equivalent Replacement Evaluation for MOV Gearbox Lubricant
MUG Conference All in One Grease - An Update On MOV Long Life
Stem Lubricant Aging Research
2004 MUG Conference MOV Long Life Limit Switch Applications (not
posted yet, contact us for a copy)
2005 MUG Conference MOV Long Life Grease Condition Monitoring Tests
(not posted yet, contact us for a copy)
EPRI (Electric Power Research Institute)
Comparative Analysis of Nebula and MOV Long Life Greases for
Limitorque Main Gearbox Applications, Report 1003483, December 2002. Summary
only, EPRI member can download.
(Nuclear Regulatory Commission) MOV Stem Lubricant Aging Research, March 2003,
Click "Begin Adams Search", then in the search box type in ML030780590 to get
the report. If you want a downloadable file click the icon under the "Image
SUPPLIERS OF MOV LONG LIFE AND MOV EXTRA
Toll free 800 305-2806 or 905 525-7192
Technology Inc., Texas
800 448-1795 x104
800 536-6070 or 770 426-6070
Valves & Automation Inc
555 Executive Drive, Willowbrook, IL
* Usually have MOV Long Life Grades 0,1 & 2 in stock as well as
MOV Extra Grades 0 &1
COG (Candu Owners Group)
COG EQ and Mixing
MUG (Motor Operated Valve Users' Group)
MUG Position Paper.pdf
EPRI (Electric Power Research Institute)
EPRI SMB Single
EPRI Main Gearbox EQ
EPRI Limit Switch
MOV Long Life 9000
Commercial Grade Dedication
TechNote Dropping Pt
QUESTIONS AND ANSWERS
Q&A MOV Long Life
Question & Answers MOV Long Life Grease
1. What's special about MOV Long Life grease?
It was reported in 1994 that some stations were experiencing problems with the
calcium complex that had been used historically. It turned out that while
'approved' that its last formulation had some disadvantages. We then started
working with stations, EPRI and others to develop a grease that would work
better in the main gearbox of valve actuators and also in the limit switch
gearbox and on the stems. The stations in particular wanted a grease that would
last much longer before it became too hard for further service. This has been
accomplished. MOV Long Life is recommended by MUG, extensively tested by COG
and EPRI and is the only approved grease for safety related Limitorque MOV's.
The Grade 0 (softer) is used as factory files, many stations use a stiffer
Grade 1 for the gearboxes and the stems and an even stiffer Grade 2 is
available for bearings. Reports so far are that MOV Long Life lasts at least 3
times as long as the now obsolete product.
2. Who's using it?
Users include many US nuclear stations as well as those in Canada, Sweden and
Spain. Work in underway on applications in France and Japan.
3. How does it perform?
MOV Long Life has outstanding oxidation resistance, as well as excellent
resistance to working (polyurea greases do not as a rule) and provides much
better corrosion protection and wear resistance. MOV Long Life for EQ
applications has been radiation tested to over 220 Mrad and also stiffens up in
contact with water so it stays in place better.
4. Who has tested it?
MOV Long Life has been independently tested by a number of utilities and by
outside organisations. This data is available in most cases and there are links
on the website to EPRI testing and the MUG Position Paper.
5. Is it compatible with our current grease?
The calcium sulphonate thickener is compatible with the calcium complex grease
recommended previously by Limitorque. This has been confirmed in testing and it
has been stated that they can mixed even for safety related valves. This is not
the same as other greases and the old calcium complex it is reportedly not
compatible with the other greases offered by the previous manufacturers.
However, while adding MOV Long Life will tend to be better than adding more of
the obsolete grease, to get all the benefits of the better performance remove
as much of old grease as possible.
6. It costs more so is it worth it?
MOV Long Life uses an expensive baseoil and it is still a low volume product
however, the main cost is associated with the extra QA and the questions
arising from it's use at nuclear plants. In addition, there are the years of
previous work and testing that have to be recovered. Given the performance and
the longer life it is indeed worth it. For fossil applications and for
non-safety related equipment there is MOV Extra. This has a good but less
expensive baseoil, it is made in large volumes and it has a further advantage
of better mobility at low temperatures.
7. What is its shelf life?
The shelf life of a product is open to some interpretation and for power plants
there is little guidance on what this means. However, some military
specifications do require longer shelf lives and specify the testing. In most
cases a time is given to reflect when the manufacturer believes that the grease
will still meet the typical performance specifications and be within the NLGI
Grade requirements. For the previous grease this was stated as being only 1
year! This might because of the age hardening and while the grease can
obviously still perform at time intervals many times this amount it does mean
that extra testing on even product from unopened pails might be required. The
stated shelf life of MOV Long Life is 5 years. Beyond this time it is
recommended that the pails be examined for oil separation and if present to mix
it back in. The grease can also be tested for penetration if required or other
tests if contamination is suspected.
8. What can be used for high radiation applications?
MOV Long Life has been radiated tested by at least four different agencies and
it has performed very well. The EPRI testing was to over 220 Mrad. In either
wet or dry applications it should do well and for bearings or other similar
applications the stiffer Grade 2 might be more suitable. It can also be used
for gear couplings although it will not be as good in centrifugal separation as
the specialty products but it should do better in other areas.
9. Can it be used in the Limitorque limit switch gearbox?
MOV Long Life has been compared against the two current products and it
outperformed them in almost every regard. It certainly should not suffer from
the age hardening of one of current products (see NRC report) and yet provides
good wear protection and much better corrosion protection. Given that the
grease is this application is seldom changed remove as much of the old grease
as possible and do not mix. MOV Long Life is being used now for this
application and the 2003 and 2004 MUG presentations.
10. Can MOV Long Life be used on stems?
MOV Long Life provides good wear protection and in testing by others it
certainly appears to perform better than the now obsolete calcium complex
grease. The Grade 1 or even the Grade 2 would be preferred. Testing by others
has shown no rate of loading effects and no significant changes in the
coefficient of friction. Stems testing by EPRI is currently underway (2004).