03302017Thu
Last updateThu, 30 Mar 2017 2pm

i

The Challenges of Slurry Valve Packing

The Challenges of Slurry Valve Packing

Because of the difficulties of dealing w...

The Many Layers of Valve Qualification

The Many Layers of Valve Qualification

While there has been much rhetoric from ...

Valves Help Achieve Net-Zero Water Use

Valves Help Achieve Net-Zero Water Use

With drought and climate change affecting ...

Valve Selection in Pulp and Paper Operations

Valve Selection in Pulp and Paper Operations

Over the centuries, the pulp and paper i...

The Weekly Report

New Products

  • ja-news-2
  • ja-news-3

Industry Headlines

Industry Headlines

Wolseley Announces Name Change, CEO Succession

16 HOURS AGO

Wolseley plc is officially changing its name to Ferguson plc, subject to shareholder approval. Ferguson is the most significant brand in the Wolseley Group of companies and accounts for 84% of the Wolseley Group’s profitability.

The company also announced that CEO Frank Roach will retire on July ...

Readmore

Spirax Sarco Employees Build Prosthetic Hands for Children

22 HOURS AGO

Spirax Sarco hosted their annual charity event at the Westin Hotel in Savannah, GA on Saturday, March 11, 2017 where participants built prosthetic hands for children in third-world countries who are missing limbs.

There are 300,000 landmine rated amputees globally and 20% of those are children. Emplo...

Readmore

Permian Drillers Acquiring Slivers of Land for Horizontal Drills

-1 DAYS AGO

With horizontal drilling in the Permian Basin allowing producers to “drill longer wells than ever before, companies such as Pioneer Natural Resources Co., Parsley Energy Inc. and Double Eagle Energy Permian LLC are increasingly haggling with other producers for slivers of land that allow them ...

Readmore

In Blow to Nuclear Industry, Westinghouse Files for Bankruptcy

21 HOURS AGO

“The Westinghouse unit of Japanese technology giant Toshiba plunged into Chapter 11 bankruptcy Wednesday as the Cranberry Township, Pa.-based division faces cost overruns and delays with its U.S. nuclear plant projects,” reports USA Today .

“The company said the bankruptcy does not aff...

Readmore

Richmond Fed: Manufacturing Grows at Fastest Rate in Nearly Seven Years

-1 DAYS AGO

Manufacturers in the fifth district were generally upbeat in March, according to the latest survey by the Federal Reserve Bank of Richmond. The index for shipments and new orders both rose and employment gains were more common. This improvement led to a composite index for manufacturing that rose from...

Readmore

Consumer Confidence Reaches 16-Year High in March

-1 DAYS AGO

The Conference Board Consumer Confidence Index, which had increased in February, improved sharply in March. The Index now stands at 125.6, up from 116.1 in February. The Present Situation Index rose from 134.4 to 143.1 and the Expectations Index increased from 103.9 last month to 113.8.

“Consum...

Readmore

Grease for Motor Actuator Maintenance

Maintaining the right amount of grease inside motor actuators that use grease for lubrication is a vital part of valve maintenance, and can save time and money by preventing problems before they happen. Inadequate lubrication is often the culprit in a malfunctioning motor actuator, and understanding how to effectively manage grease in motor actuators can be a simple way to keep costs down and to keep actuators out of the repair shop.

Motor actuators must have the correct amount and type of grease in the gear case to provide for trouble-free operation.

 

Getting Inside
The first step is getting inside the actuator. Actuators have from two to four grease plugs to allow adding and checking the level of grease. The quality, quantity, and consistency of the grease in the actuator should initially be checked every 18 months, then at a frequency derived from the results. This inspection must be accomplished through these grease plugs.

Motor actuators are built to operate on the partial immersion principle. What matters is whether or not the "worm" is totally immersed in grease. This is to ensure that the efficiency of the worm/worm gear set is operating at its highest level, because this gear set is the most inefficient gear set in the actuator, operating at about 20% to 25%.

Due to the heat of the sun or system operation, the gear box is pressurized, which is why just filling up the gear box with grease causes the grease to push through the seals and into the motor windings and/or into the limit switch compartment.

To determine the correct amount of grease to add to a gear box, perform an inspection by using one of the many "fill and drain" plugs to ensure the worm is totally immersed in grease. When the actuator is mounted in a different orientation, the amount of grease needed to totally immerse the worm will change.

If your actuator is disassembled for repairs or rebuilding, these grease plugs should all be removed, cleaned, and reinstalled. Sometimes these plugs will be corroded in the housing and must be drilled out. Due to the metal chips that will fall into the grease, don't drill them out during operation. Instead, remove them during the rebuild when the inside is exposed.

The drive sleeve in an actuator extends through the housing on both the bottom and top sides. A seal is used to prevent leakage of grease at this penetration. The lower drive sleeve is held in place by a seal retainer, which is installed and removed, from the bottom of the actuator. This seal retainer is held in place by screws, bolts, or just a press fit on different sizes of actuators.

When the actuator is disassembled for repair or rebuild, this seal retainer does not need to be removed to fish out the seal and replace it. However, it should be removed to allow the rebuilt drive sleeve to be installed first. If the seal is installed first, and then the drive sleeve, there is no way to ensure that the seal is not nicked or rolled during the drive sleeve installation.

Grease in the main gear box will not flow into the clutch housing compartment of the actuator, so this compartment must also have grease added to cover the motor pinion/worm shaft clutch gear set. Fill this area just enough to cover the gear set-not too full.

The actuator can be mounted in any position since it has a totally sealed gear case. However, mounting positions that would cause vulnerable areas of the actuator (e.g., motor and limit switch compartment) to be saturated with grease in the event of a seal failure are not recommended.

The Right Grease
Use only the correct type when adding grease to your actuators. This means the grease must:

 

  • contain an "EP" additive
  • be suitable for the temperature range needed
  • be water and heat resistant and non-separating
  • not create more than 8% swell in Buna N or Viton seals
  • not contain any grit, abrasive, or fillers
  • not slump-preferred NLGI grade 0 to 1
  • not be corrosive to steel gears, ball, or roller bearings
  • have a dropping point above 316° F for temperature ranges of -20° F to 150° F.

In addition to the above, keep in mind that grease is made up of a filler (soap) and oil. Different types of fillers are used and not all types will mix well with each other. If you are going to add grease, use the same type of grease in the gearbox or ensure the new grease is compatible.

Regularly checking the level and quality of grease inside motor actuators will provide results that speak for themselves. Quite literally, proper lubrication makes a motor actuator function more smoothly, and keeps it lasting longer and working at maximum efficiency at very little cost.

  • Latest Post

  • Popular

  • Links

  • Events

Advertisement

Looking for a career in the Valve Industry?

ValveCareers Horiz

To learn more, watch the videos below or visit ValveCareers.com a special initiative of the Valve Manufacturers Association